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Sample records for rat mastomys natalensis

  1. The ecology of Praomys (Mastomys) natalensis in southern Africa

    PubMed Central

    Isaäcson, Margaretha

    1975-01-01

    The only non-human host of Lassa virus so far identified is the multimammate mouse, Praomys (Mastomys) natalensis, but its precise role in the natural Lassa fever cycle remains to be determined. This species is also an important link in the plague cycle in southern Africa and is one of the commonest rodents of Africa. It is a prolific breeder and can be kept and bred easily in captivity. It is thus an excellent laboratory animal, although it needs to be handled with care because it is aggressive towards man and bites readily. The current status of knowledge of its taxonomy, ecology, distribution, and role as a disease vector is reviewed, but attention is drawn to the possibly disastrous consequences of attempting to eradicate a vector species before the natural cycle of the disease and the ecology of the vector are fully understood. ImagesFig. 2 PMID:1085218

  2. Laboratory test of seven rodenticides for the control of Mastomys natalensis.

    PubMed

    Gill, J E; Redfern, R

    1979-10-01

    Laboratory feeding tests were carried out to assess the efficacy of seven rodenticides against Mastomys natalensis. The poisons (warfarin, coumatetralyl, difenacoum, brodifacoum, bromadiolone, calciferol and zinc phosphide) were all toxic at the concentrations normally used against Rattus norvegicus (Berk.), although several were unpalatable. Trials are now needed to demonstrate the relative efficacy of these poisons in the field, but it is likely that, given suitable bait formulations, they would all be useful as practical control agents. PMID:489963

  3. The biology, behaviour, and ecology of Mastomys natalensis in southern Africa

    PubMed Central

    Coetzee, Cornelius G.

    1975-01-01

    The multimammate mouse, Mastomys natalensis, is the most widespread and common rodent in Africa south of the Sahara. It is an ideal carrier of normally non-human diseases to the domestic environment, not only because of its semi-commensal habit but also because of a combination of other behavioural and ecological factors. Of these, the most important is an exceptionally high propagation rate. PMID:1085219

  4. Laboratory test of seven rodenticides for the control of Mastomys natalensis.

    PubMed Central

    Gill, J. E.; Redfern, R.

    1979-01-01

    Laboratory feeding tests were carried out to assess the efficacy of seven rodenticides against Mastomys natalensis. The poisons (warfarin, coumatetralyl, difenacoum, brodifacoum, bromadiolone, calciferol and zinc phosphide) were all toxic at the concentrations normally used against Rattus norvegicus (Berk.), although several were unpalatable. Trials are now needed to demonstrate the relative efficacy of these poisons in the field, but it is likely that, given suitable bait formulations, they would all be useful as practical control agents. PMID:489963

  5. Gairo virus, a novel arenavirus of the widespread Mastomys natalensis: Genetically divergent, but ecologically similar to Lassa and Morogoro viruses.

    PubMed

    Gryseels, Sophie; Rieger, Toni; Oestereich, Lisa; Cuypers, Bart; Borremans, Benny; Makundi, Rhodes; Leirs, Herwig; Günther, Stephan; Goüy de Bellocq, Joëlle

    2015-02-01

    Despite its near pan-African range, the Natal multimammate mouse, Mastomys natalensis, carries the human pathogen Lassa virus only in West Africa, while the seemingly non-pathogenic arenaviruses Mopeia, Morogoro, and Luna have been detected in this semi-commensal rodent in Mozambique/Zimbabwe, Tanzania and Zambia, respectively. Here, we describe a novel arenavirus in M. natalensis from Gairo district of central Tanzania, for which we propose the name "Gairo virus". Surprisingly, the virus is not closely related with Morogoro virus that infects M. natalensis only 90km south of Gairo, but clusters phylogenetically with Mobala-like viruses that infect non-M. natalensis host species in Central African Republic and Ethiopia. Despite the evolutionary distance, Gairo virus shares basic ecological features with the other M. natalensis-borne viruses Lassa and Morogoro. Our data show that M. natalensis, carrying distantly related viruses even in the same geographical area, is a potent reservoir host for a variety of arenaviruses.

  6. Polymorphism in vkorc1 Gene of Natal Multimammate Mice, Mastomys natalensis, in Tanzania.

    PubMed

    Gryseels, Sophie; Leirs, Herwig; Makundi, Rhodes; Goüy de Bellocq, Joëlle

    2015-01-01

    Resistance of rodents to anticoagulant rodenticides has emerged in several areas across the world. Single nucleotide mutations in the vkorc1 gene have been shown to elicit various levels of anticoagulant resistance, and these mutations are prevalent in several Rattus and Mus musculus populations. In sub-Saharan Africa, the Natal multimammate mouse, Mastomys natalensis, is one of the most damaging pests to crops, and anticoagulant poisons such as bromadiolone are frequently used to control these rodents in agricultural fields. Here, we investigate if vkorc1 shows any polymorphism in natural populations of M. natalensis. We sequenced the third exon of vkorc1 of 162 M. natalensis captured from 14 different agricultural sites in Morogoro Region, Tanzania. In addition to 6 SNPs in the noncoding flanking region, we detected 3 nonsynonymous SNPs in this exon: 10 animals (6.2%) carried a Leu108Val variant, 2 animals (1.2%) an Ala140Thr variant, and 1 animal (0.6 %) an Arg100His variant, all 3 in heterozygous form. Ala140Thr is just one residue from a mutation known to be involved in anticoagulant resistance in Rattus and Mus. While in vitro or in vivo experiments are needed to link vkorc1 genetic polymorphisms to level of VKOR activity and anticoagulant susceptibility, our results suggest that M. natalensis individuals may vary in their response to anticoagulant rodenticides. This is the first vkorc1 sequence data from a species outside the Rattus or Mus genera, and for the first time from a rodent species endemic to Africa. PMID:26223233

  7. Transcriptome analysis of Mastomys natalensis papillomavirus in productive lesions after natural infection.

    PubMed

    Salvermoser, Melanie; Chotewutmontri, Sasithorn; Braspenning-Wesch, Ilona; Hasche, Daniel; Rösl, Frank; Vinzón, Sabrina E

    2016-07-01

    Mastomys coucha, an African rodent, is a useful animal model of papillomavirus infection, as it develops both premalignant and malignant skin tumors as a consequence of a persistent infection with Mastomys natalensis papillomavirus (MnPV). In this study, we mapped the MnPV transcriptome in productive lesions by both classical molecular techniques and high-throughput RNA sequencing. Combination of these methods revealed a complex and comprehensive transcription map, with novel splicing events not described in other papillomaviruses. Furthermore, these splicing occurrences could potentially lead to the expression of novel E2, E1∧E4, E7 and L2 isoforms. Expression level estimation of each transcript showed that late-region mRNAs considerably outnumber early transcripts, with species coding for L1 and E1∧E4 being the most abundant. In summary, the full transcription map assembled in this study will allow us to further understand MnPV gene expression and the mechanisms that lead to natural tumour development. PMID:27043420

  8. Shedding dynamics of Morogoro virus, an African arenavirus closely related to Lassa virus, in its natural reservoir host Mastomys natalensis

    PubMed Central

    Borremans, Benny; Vossen, Raphaël; Becker-Ziaja, Beate; Gryseels, Sophie; Hughes, Nelika; Van Gestel, Mats; Van Houtte, Natalie; Günther, Stephan; Leirs, Herwig

    2015-01-01

    Arenaviruses can cause mild to severe hemorrhagic fevers. Humans mainly get infected through contact with infected rodents or their excretions, yet little is known about transmission dynamics within rodent populations. Morogoro virus (MORV) is an Old World arenavirus closely related to Lassa virus with which it shares the same host species Mastomys natalensis. We injected MORV in its host, and sampled blood and excretions at frequent intervals. Infection in adults was acute; viral RNA disappeared from blood after 18 days post infection (dpi) and from excretions after 39 dpi. Antibodies were present from 7 dpi and never disappeared. Neonatally infected animals acquired a chronic infection with RNA and antibodies in blood for at least 3 months. The quantified excretion and antibody patterns can be used to inform mathematical transmission models, and are essential for understanding and controlling transmission in the natural rodent host populations. PMID:26022445

  9. Increased Incidence of Squamous Cell Carcinomas in Mastomys natalensis Papillomavirus E6 Transgenic Mice during Two-Stage Skin Carcinogenesis

    PubMed Central

    Helfrich, Iris; Chen, Min; Schmidt, Rainer; Fürstenberger, Gerhard; Kopp-Schneider, Annette; Trick, David; Gröne, Hermann-Josef; zur Hausen, Harald; Rösl, Frank

    2004-01-01

    Papillomaviruses cause certain forms of human cancers, most notably carcinomas of the uterine cervix. In contrast to the well-established involvement of papillomavirus infection in the etiology of cervical carcinomas and in carcinomas of a rare hereditary condition, epidermodysplasia verruciformis, a causative role for cutaneous human papillomavirus types in the development of nonmelanoma skin cancer has not been proven. In order to better understand the functions of individual genes of cutaneous papillomavirus types, we generated transgenic mice carrying oncogene E6 of the Mastomys natalensis papillomavirus (MnPV), which causes keratoacanthomas of the skin in its natural host. In the present study, we demonstrate that under conditions of experimental two-stage skin carcinogenesis, fast-paced squamous cell carcinomas develop in nearly 100% of MnPV E6 transgenic mice in comparison to 10% in their nontransgenic littermates (log rank test; P < 0.0001). Therefore, we conclude that the MnPV E6 transgene favors the malignant progression of chemically induced tumors. Whereas an activating H-ras mutation is a consistent feature in benign and malignant tumors in wild-type mice, the majority of papillomas and keratoacanthomas and all squamous cell carcinomas obtained in MnPV E6 transgenic mice contain nonmutated ras alleles. These results indicate that the development of squamous cell carcinomas in MnPV E6 transgenic mice does not depend on an activated H-ras oncogene. PMID:15078961

  10. The Impact of Human Conflict on the Genetics of Mastomys natalensis and Lassa Virus in West Africa

    PubMed Central

    Denys, Christiane; ter Meulen, Jan; Wirth, Thierry

    2012-01-01

    Environmental changes have been shown to play an important role in the emergence of new human diseases of zoonotic origin. The contribution of social factors to their spread, especially conflicts followed by mass movement of populations, has not been extensively investigated. Here we reveal the effects of civil war on the phylogeography of a zoonotic emerging infectious disease by concomitantly studying the population structure, evolution and demography of Lassa virus and its natural reservoir, the rodent Mastomys natalensis, in Guinea, West Africa. Analysis of nucleoprotein gene sequences enabled us to reconstruct the evolutionary history of Lassa virus, which appeared 750 to 900 years ago in Nigeria and only recently spread across western Africa (170 years ago). Bayesian demographic inferences revealed that both the host and the virus populations have gone recently through severe genetic bottlenecks. The timing of these events matches civil war-related mass movements of refugees and accompanying environmental degradation. Forest and habitat destruction and human predation of the natural reservoir are likely explanations for the sharp decline observed in the rodent populations, the consequent virus population decline, and the coincident increased incidence of Lassa fever in these regions. Interestingly, we were also able to detect a similar pattern in Nigeria coinciding with the Biafra war. Our findings show that anthropogenic factors may profoundly impact the population genetics of a virus and its reservoir within the context of an emerging infectious disease. PMID:22615894

  11. Chemotherapeutic studies on Litomosoides carinii infection of Mastomys natalensis. 8. The action of furazolidone on adult worms and microfilariae.

    PubMed

    Wegerhof, P H; Lämmler, G; Sänger, I; Zahner, H

    1979-09-01

    After oral administration of furazolidone in doses of 5 x 50 mg/kg and 1 x 100 mg/kg body weight to Litomosoides carinii--infected Mastomys natalensis microfilaraemia decreased continuously and was reduced by more than 98% 42 days after start of treatment. After the 5-day treatment all adult female and male worms were found dead and encapsulated within 2 weeks, whereas after the single dose 100% of the female parasites were encapsulated 28 days after treatment. In untreated animals quantiative examinations of the intrauterine stages showed an average number of 500 x 103 embryos per adult female worm. Following the 5-day treatment the number of embryos per female parasite was reduced after 42 days to 12.5 x 103, and after the single treatment to 26.9 x 103. By classification into 5 different stages (2- and 4-cell stages, Morula stage, "Horse-shoe" stage, "Ring" and "Brezel" stages, and intruterine microfilariae) an embryogram showed a continuous increase in pathologically-altered embryos during the whole observation period. The 2- and 4-cell stages suffered the most damaged. By 16 days after the end of the 5-day treatment and by 28 days after the single treatment all embryonic stages in the uteri were found to be pathologically altered. Furazolidone possessess high macrofilaricidal activity together with a considerable adverse effect on embryognesis and some delayed effect on microfilaraemia. PMID:543002

  12. The impact of human conflict on the genetics of Mastomys natalensis and Lassa virus in West Africa.

    PubMed

    Lalis, Aude; Leblois, Raphaël; Lecompte, Emilie; Denys, Christiane; Ter Meulen, Jan; Wirth, Thierry

    2012-01-01

    Environmental changes have been shown to play an important role in the emergence of new human diseases of zoonotic origin. The contribution of social factors to their spread, especially conflicts followed by mass movement of populations, has not been extensively investigated. Here we reveal the effects of civil war on the phylogeography of a zoonotic emerging infectious disease by concomitantly studying the population structure, evolution and demography of Lassa virus and its natural reservoir, the rodent Mastomys natalensis, in Guinea, West Africa. Analysis of nucleoprotein gene sequences enabled us to reconstruct the evolutionary history of Lassa virus, which appeared 750 to 900 years ago in Nigeria and only recently spread across western Africa (170 years ago). Bayesian demographic inferences revealed that both the host and the virus populations have gone recently through severe genetic bottlenecks. The timing of these events matches civil war-related mass movements of refugees and accompanying environmental degradation. Forest and habitat destruction and human predation of the natural reservoir are likely explanations for the sharp decline observed in the rodent populations, the consequent virus population decline, and the coincident increased incidence of Lassa fever in these regions. Interestingly, we were also able to detect a similar pattern in Nigeria coinciding with the Biafra war. Our findings show that anthropogenic factors may profoundly impact the population genetics of a virus and its reservoir within the context of an emerging infectious disease.

  13. The impact of human conflict on the genetics of Mastomys natalensis and Lassa virus in West Africa.

    PubMed

    Lalis, Aude; Leblois, Raphaël; Lecompte, Emilie; Denys, Christiane; Ter Meulen, Jan; Wirth, Thierry

    2012-01-01

    Environmental changes have been shown to play an important role in the emergence of new human diseases of zoonotic origin. The contribution of social factors to their spread, especially conflicts followed by mass movement of populations, has not been extensively investigated. Here we reveal the effects of civil war on the phylogeography of a zoonotic emerging infectious disease by concomitantly studying the population structure, evolution and demography of Lassa virus and its natural reservoir, the rodent Mastomys natalensis, in Guinea, West Africa. Analysis of nucleoprotein gene sequences enabled us to reconstruct the evolutionary history of Lassa virus, which appeared 750 to 900 years ago in Nigeria and only recently spread across western Africa (170 years ago). Bayesian demographic inferences revealed that both the host and the virus populations have gone recently through severe genetic bottlenecks. The timing of these events matches civil war-related mass movements of refugees and accompanying environmental degradation. Forest and habitat destruction and human predation of the natural reservoir are likely explanations for the sharp decline observed in the rodent populations, the consequent virus population decline, and the coincident increased incidence of Lassa fever in these regions. Interestingly, we were also able to detect a similar pattern in Nigeria coinciding with the Biafra war. Our findings show that anthropogenic factors may profoundly impact the population genetics of a virus and its reservoir within the context of an emerging infectious disease. PMID:22615894

  14. Care of Mastomys in the laboratory.

    PubMed

    Scholz, Jodi; Wilson, Steven

    2016-05-20

    Mastomys rodents occupy a valuable niche in biomedical research, but there is very little published information regarding how to care for them in the laboratory. Here we provide information about the physical and behavioral characteristics of this unusual laboratory rodent, its taxonomic history, common diseases that affect it, and its use in research. We also provide housing recommendations based upon almost 15 years of experience successfully maintaining a colony of Mastomys coucha at our institution.

  15. Ultrastructure of ECL cells in Mastomys after long-term treatment with H2 receptor antagonist loxtidine.

    PubMed

    Vigen, Reidar Alexander; Kidd, Mark; Modlin, Irvin M; Chen, Duan; Zhao, Chun-Mei

    2012-06-01

    Gastric ECL-cell hyperplasia and carcinoids (ECLoma) develop after 1 year in rats treated with omeprazole or 2 months in Mastomys treated with loxtidine. The aim of this study was to examine the ultrastructure of ECL cells in Mastomys after loxtidine treatment with an attempt to evaluate whether an impairment of autophagy was involved in the tumorigenesis. Mastomys were given loxtidine for 8 or 27 weeks. Morphological analysis of ECL cells showed that (1) cell size was not increased after 8 or 27 weeks; (2) secretory vesicles, a hallmark feature of welldifferentiated ECL cells, were unchanged after 8 weeks but reduced after 27 weeks; (3) granules were reduced after 8 or 27 weeks; (4) microvesicles were unchanged after the treatment; and (5) vacuoles and lipofuscin bodies were found occasionally after 8 weeks but not at 27 weeks. In addition, the appearance of ECL-cell ultrastructure differed between loxtidine-treated Mastomys and rats treated with omeprazole or subjected to antrectomy, but was similar between Mastomys treated with loxtidine for 27 weeks and mice deficient in CCK(2) receptor. We suggest that the ultrastructure of ECL cells in Mastomys after long-term treatment with loxtidine displayed an impaired formation of vacuoles and lipofuscin bodies, markers of the autophagic pathway.

  16. Biologically active constituents of leaves and roots of Aloe arborescens var. natalensis.

    PubMed

    Hirata, T; Suga, T

    1977-01-01

    Several biologically active substances, such as aloenin (1), magnesium lactate, aloe-emodin (4), barbaloin (5), and succinic acid, were found to be contained in the leaf juice of Aloe arborescens Mill. var. natalensis Berger, which has widely been used in domestic medicines. Aloenin (1) and magnesium lactate were elucidated to exhibit an inhibitory action on the gastric juice secretion of rats. Various constituents other than the above bioactive substances were found in the leaves and the roots of the plant.

  17. Commiphora molmol extracts as plant molluscicide against Lymnaea natalensis.

    PubMed

    Massoud, Ahmad M; El-Shazly, Atef M; Nagaty, Ibrahim Maged; Morsy, Tosson A

    2007-08-01

    Two extracts from the herbal plant, Commiphora molmol showed a high molluscicidal effect against Lymnaea natalensis. The oil extract was more potent than the oleo-resin. A concentration of 10 ppm of the oil extract killed 100% of L. natalensis after 5th day, but the oleo-resin extract killed 100% of them at a concentration 20 ppm after 5th day. PMID:17985579

  18. Antimicrobial activity of the solvent fractions from Bulbine natalensis Tuber.

    PubMed

    Yakubu, M T; Mostafa, M; Ashafa, A O T; Afolayan, A J

    2012-01-01

    Bulbine natalensis Baker has been acclaimed to be used as an antimicrobial agent in the folklore medicine of South Africa without scientific evidence to substantiate or refute this claim. In view of this, the in vitro antimicrobial activity of solvent fractions (ethanol, ethyl acetate, n-butanol and water) from Bulbine natalensis Tuber against 4 Gram positive and 12 Gram negative bacteria as well as 3 fungal species were investigated using agar dilution. The ethanolic extract, n-butanol and ethyl acetate fractions inhibited 75, 87.5 and 100% respectively of the bacterial species in this study. The ethanolic, n-butanol and ethyl acetate fractions produced growth inhibition at MIC range of 1-10, 3-10 as well as 1 and 5 mg/ml respectively whereas the water fraction did not inhibit the growth of any of the bacterial species. Again, it was only the ethyl acetate fraction that inhibited the growth of Shigelli flexneri, Staphyloccus aureus and Escherichia coli. The ethanolic, ethyl acetate and n-butanolic fractions dose dependently inhibited the growth of Aspergillus niger and A. flavus whereas the water fraction produced 100% growth inhibition of the Aspergillus species at all the doses investigated. In contrast, no growth inhibition was produced on Candida albicans. The growth inhibition produced by the solvent fractions of B. natalensis Tuber in this study thus justifies the acclaimed use of the plant as an antimicrobial agent. The ethyl acetate fraction was the most potent. PMID:23983381

  19. Establishment of an Immortalized Skin Keratinocyte Cell Line Derived from the Animal Model Mastomys coucha

    PubMed Central

    Hasche, Daniel; Stephan, Sonja; Savelyeva, Larissa; Westermann, Frank; Rösl, Frank

    2016-01-01

    In the present report we describe the establishment of a spontaneous immortalized skin keratinocyte cell line derived from the skin of the multimammate rodent Mastomys coucha. These animals are used in preclinical studies for a variety of human diseases such as infections with nematodes, bacteria and papillomaviruses, especially regarding cutaneous manifestations such as non-melanoma skin cancer. Here we characterize the cells in terms of their origin and cytogenetic features. Searching for genomic signatures, a spontaneous mutation in the splicing donor sequence of Trp53 (G to A transition at the first position of intron 7) could be detected. This point mutation leads to alternative splicing and to a premature stop codon, resulting in a truncated and, in turn, undetectable form of p53, probably contributing to the process of immortalization. Mastomys coucha-derived skin keratinocytes can be used as an in vitro system to investigate molecular and immunological aspects of infectious agent interactions with their host cells. PMID:27533138

  20. Establishment of an Immortalized Skin Keratinocyte Cell Line Derived from the Animal Model Mastomys coucha.

    PubMed

    Hasche, Daniel; Stephan, Sonja; Savelyeva, Larissa; Westermann, Frank; Rösl, Frank; Vinzón, Sabrina E

    2016-01-01

    In the present report we describe the establishment of a spontaneous immortalized skin keratinocyte cell line derived from the skin of the multimammate rodent Mastomys coucha. These animals are used in preclinical studies for a variety of human diseases such as infections with nematodes, bacteria and papillomaviruses, especially regarding cutaneous manifestations such as non-melanoma skin cancer. Here we characterize the cells in terms of their origin and cytogenetic features. Searching for genomic signatures, a spontaneous mutation in the splicing donor sequence of Trp53 (G to A transition at the first position of intron 7) could be detected. This point mutation leads to alternative splicing and to a premature stop codon, resulting in a truncated and, in turn, undetectable form of p53, probably contributing to the process of immortalization. Mastomys coucha-derived skin keratinocytes can be used as an in vitro system to investigate molecular and immunological aspects of infectious agent interactions with their host cells. PMID:27533138

  1. Presumptive horizontal symbiont transmission in the fungus-growing termite Macrotermes natalensis.

    PubMed

    de Fine Licht, H H; Boomsma, J J; Aanen, D K

    2006-10-01

    All colonies of the fungus-growing termite Macrotermes natalensis studied so far are associated with a single genetically variable lineage of Termitomyces symbionts. Such limited genetic variation of symbionts and the absence of sexual fruiting bodies (mushrooms) on M. natalensis mounds would be compatible with clonal vertical transmission, as is known to occur in Macrotermes bellicosus. We investigated this hypothesis by analysing DNA sequence polymorphisms as codominant SNP markers of four single-copy gene fragments of Termitomyces isolates from 31 colonies of M. natalensis. A signature of free recombination was found, indicative of frequent sexual horizontal transmission. First, all 31 strains had unique multilocus genotypes. Second, SNP markers (n = 55) were largely in Hardy-Weinberg equilibrium (90.9%) and almost all possible pairs of SNPs between genetically unlinked loci were in linkage equilibrium (96.7%). Finally, extensive intragenic recombination was found, especially in the EF1alpha fragment. Substantial genetic variation and a freely recombining population structure can only be explained by frequent horizontal and sexual transmission of Termitomyces. The apparent variation in symbiont transmission mode among Macrotermes species implies that vertical symbiont transmission can evolve rapidly. The unexpected finding of horizontal transmission makes the apparent absence of Termitomyces mushrooms on M. natalensis mounds puzzling. To our knowledge, this is the first detailed study of the genetic population structure of a single lineage of Termitomyces.

  2. Susceptibility of two-week old Lymnaea natalensis to some plant extracts.

    PubMed

    Kela, S L; Ogunsusi, R A; Ogbogu, V C; Nwude, N

    1989-01-01

    The molluscacidal potency of 17 Nigerian plants extracted by the unevaporated crude water (UECW) method was evaluated on two-week old Lymnaea natalensis Krauss. Five extracts were not active but extracts of Balanites aegytiaca, Blighia sapida, Boswellia dalzielii, Cissampelos mucronata, Detarium microcarpum, Kigelia africana, Opilia celtidifolia, Parkia clappertoniana, Polygonum limbatum, Pseudocedrela kotschyi, Nauclea latifolia and Securidaca longipedunculata were molluscacidal. There is potential for their future use in the integrated control of Lymnaea natalensis, as well as other snails. Mortality data for lethal concentration values for all extracts were analysed by use of probit transformation. The upper and lower fiducial limits of the LC50 (P = 0.05) were also determined. PMID:2626571

  3. Reflecting optics in the diverticular eye of a deep-sea barreleye fish (Rhynchohyalus natalensis).

    PubMed

    Partridge, J C; Douglas, R H; Marshall, N J; Chung, W-S; Jordan, T M; Wagner, H-J

    2014-05-01

    We describe the bi-directed eyes of a mesopelagic teleost fish, Rhynchohyalus natalensis, that possesses an extensive lateral diverticulum to each tubular eye. Each diverticulum contains a mirror that focuses light from the ventro-lateral visual field. This species can thereby visualize both downwelling sunlight and bioluminescence over a wide field of view. Modelling shows that the mirror is very likely to be capable of producing a bright, well focused image. After Dolichopteryx longipes, this is only the second description of an eye in a vertebrate having both reflective and refractive optics. Although superficially similar, the optics of the diverticular eyes of these two species of fish differ in some important respects. Firstly, the reflective crystals in the D. longipes mirror are derived from a tapetum within the retinal pigment epithelium, whereas in R. natalensis they develop from the choroidal argentea. Secondly, in D. longipes the angle of the reflective crystals varies depending on their position within the mirror, forming a Fresnel-type reflector, but in R. natalensis the crystals are orientated almost parallel to the mirror's surface and image formation is dependent on the gross morphology of the diverticular mirror. Two remarkably different developmental solutions have thus evolved in these two closely related species of opisthoproctid teleosts to extend the restricted visual field of a tubular eye and provide a well-focused image with reflective optics.

  4. Pollinators, "mustard oil" volatiles, and fruit production in flowers of the dioecious tree Drypetes natalensis (Putranjivaceae).

    PubMed

    Johnson, Steven D; Griffiths, Megan E; Peter, Craig I; Lawes, Michael J

    2009-11-01

    The Putranjivaceae is an enigmatic family, notable for being the only lineage outside the Capparales to possess the glucosinolate biochemical pathway, which forms the basis of an induced chemical defense system against herbivores (the "mustard oil bomb"). We investigated the pollination biology and floral scent chemistry of Drypetes natalensis (Putranjivaceae), a dioecious subcanopy tree with flowers borne on the stem (cauliflory). Flowering male trees were more abundant than female ones and produced about 10-fold more flowers. Flowers of both sexes produce copious amounts of nectar on disc-like nectaries accessible to short-tongued insects. The main flower visitors observed were cetoniid beetles, bees, and vespid wasps. Pollen load analysis indicated that these insects exhibit a high degree of fidelity to D. natalensis flowers. Insects effectively transfer pollen from male to female plants resulting in about 31% of female flowers developing fruits with viable seeds. Cetoniid beetles showed significant orientation toward the scent of D. natalensis flowers in a Y-maze olfactometer. The scents of male and female flowers are similar in chemical composition and dominated by fatty acid derivatives and isothiocyanates from the glucosinolate pathway. The apparent constitutive emission of isothiocyanates raises interesting new questions about their functional role in flowers. PMID:21622327

  5. Comparative toxicity of Paraquat herbicide and some plant extracts in Lymnaea natalensis snails.

    PubMed

    Bakry, Fayez A; Eleiwa, Mona E; Taha, Samir A; Ismil, Somya M

    2016-01-01

    Paraquat has been shown to be a highly toxic compound for humans and animals, and many cases of acute poisoning and death have been reported over the past few decades. The present study was undertaken to evaluate comprehensively herbicides (Paraquat) and some plant extracts to biochemical aspects of Lymnaea natalensis snails. It was found that the exposure of L. natalensis to Paraquat and plant extracts led to a significant reduction in the infectivity of Fasciola gigantica miracidia to the snail. The glucose level in hemolymph of exposed snails was elevated, while the glycogen showed a decrease in soft tissues when compared with the control group. In addition, the activity level of some enzymes representing glycolytic enzymes as hexokinase (HK), pyruvate kinase (PK), phosphofructokinase (PFK), lactate dehydrogenase (LDH), and glucose phosphate isomerase (GPI) in snail's tissues were reduced in response to the treatment. It was concluded that the pollution of the aquatic environment by herbicide would adversely affect the metabolism of the L. natalensis snails. Snails treated with Agave attenuate, Ammi visnaga, and Canna iridiflora plant had less toxic effect compared to snails treated with Paraquat. PMID:24081640

  6. Reflecting optics in the diverticular eye of a deep-sea barreleye fish (Rhynchohyalus natalensis).

    PubMed

    Partridge, J C; Douglas, R H; Marshall, N J; Chung, W-S; Jordan, T M; Wagner, H-J

    2014-05-01

    We describe the bi-directed eyes of a mesopelagic teleost fish, Rhynchohyalus natalensis, that possesses an extensive lateral diverticulum to each tubular eye. Each diverticulum contains a mirror that focuses light from the ventro-lateral visual field. This species can thereby visualize both downwelling sunlight and bioluminescence over a wide field of view. Modelling shows that the mirror is very likely to be capable of producing a bright, well focused image. After Dolichopteryx longipes, this is only the second description of an eye in a vertebrate having both reflective and refractive optics. Although superficially similar, the optics of the diverticular eyes of these two species of fish differ in some important respects. Firstly, the reflective crystals in the D. longipes mirror are derived from a tapetum within the retinal pigment epithelium, whereas in R. natalensis they develop from the choroidal argentea. Secondly, in D. longipes the angle of the reflective crystals varies depending on their position within the mirror, forming a Fresnel-type reflector, but in R. natalensis the crystals are orientated almost parallel to the mirror's surface and image formation is dependent on the gross morphology of the diverticular mirror. Two remarkably different developmental solutions have thus evolved in these two closely related species of opisthoproctid teleosts to extend the restricted visual field of a tubular eye and provide a well-focused image with reflective optics. PMID:24648222

  7. Reflecting optics in the diverticular eye of a deep-sea barreleye fish (Rhynchohyalus natalensis)

    PubMed Central

    Partridge, J. C.; Douglas, R. H.; Marshall, N. J.; Chung, W.-S.; Jordan, T. M.; Wagner, H.-J.

    2014-01-01

    We describe the bi-directed eyes of a mesopelagic teleost fish, Rhynchohyalus natalensis, that possesses an extensive lateral diverticulum to each tubular eye. Each diverticulum contains a mirror that focuses light from the ventro-lateral visual field. This species can thereby visualize both downwelling sunlight and bioluminescence over a wide field of view. Modelling shows that the mirror is very likely to be capable of producing a bright, well focused image. After Dolichopteryx longipes, this is only the second description of an eye in a vertebrate having both reflective and refractive optics. Although superficially similar, the optics of the diverticular eyes of these two species of fish differ in some important respects. Firstly, the reflective crystals in the D. longipes mirror are derived from a tapetum within the retinal pigment epithelium, whereas in R. natalensis they develop from the choroidal argentea. Secondly, in D. longipes the angle of the reflective crystals varies depending on their position within the mirror, forming a Fresnel-type reflector, but in R. natalensis the crystals are orientated almost parallel to the mirror's surface and image formation is dependent on the gross morphology of the diverticular mirror. Two remarkably different developmental solutions have thus evolved in these two closely related species of opisthoproctid teleosts to extend the restricted visual field of a tubular eye and provide a well-focused image with reflective optics. PMID:24648222

  8. Setaria digitata microfilaraemia in Mastomys coucha: an animal model for chemotherapeutic and immunobiological studies.

    PubMed

    Mukhopadhyay, S; Dash, A P; Ravindran, B

    1996-10-01

    Intraperitoneal implantation of adult gravid females of the bovine filarial parasite, Setaria digitata in Mastomys coucha was found to induce microfilaraemia lasting for about 125 days. The microfilariae (mf) could be detected as early as 4 days post-implantation (p.i.) and peak levels of about 30 mf in 20 microliters of blood were observed by 21 days. A significant positive correlation was found between mf density and the body weight of recipients pre-implantation. The implanted adult worms were generally viable only for less than 1 week. Implantation resulted in a significant decrease in total leucocytes and erythrocytes, induction of eosinophilia, splenomegaly and anti-erythrocyte autoantibodies. The microfilariae in circulation developed into 3rd-stage infective larvae (L3) when fed onto Aedes aegypti (refm, Liverpool strain). The mf in circulation were found to be eliminated by oral administration of diethylcarbamazine citrate, indicating the usefulness of this model for screening potential anti-microfilarial drugs. During the microfilaraemic phase, priming with tetanus toxoid (TT) resulted in significantly decreased production of anti-toxin levels indicating a state of generalized immunosuppression. Induction of antibodies to various fractionated antigenic components of adult parasites could be demonstrated by enzyme immunoassay (EIA) in M. coucha implanted with live or cold-stunned adult worms. The S. digitata-M. coucha model thus is found amenable to perform chemotherapeutic and immunobiological investigations in experimental filariasis. PMID:8873474

  9. Influence of certain fertilizers on the activity of some molluscicides against Biomphalaria alexandrina and Lymnaea natalensis snails.

    PubMed

    Ragab, Fawzy; Shoukry, Nahla M

    2006-12-01

    Effect of the fertilizers (ammonium nitrate, potassium sulphate and urea) on molluscicidal activity of the molluscicides (copper sulphate, niclosamide & mollutox) against B. alexandrina and L. natalensis was investigated. The molluscicides were more potant than fertilizers. Snails were exposed for 24 hr to a fertilizers using LC0 (1/10 & LC50) then, to molluscicides. Pre-exposure to potassium sulphate caused a synergistic action with copper sulphate, niclosamide and mollutox on L. natalen-sis. Pre-exposure to urea caused an additive effect with niclo-samide and mollutox against L. natalensis and B. alexandrina respectively. Pre-exposure to ammonium nitrate caused an additive action to niclosamide on L. natalensis. Snails were exposed for 24hr to one molluscicide, then exposed to fertilizers, showed that pre-exposure to niclosamide or mollutox caused an additive effect with ammonium nitrate and potassium sulphate. Pre-exposure to mollutox caused an additive effect with urea on the two snails' sp. juvenile or adult B. alexandrina were ex-posed to LC0 of molluscicide-fertilizer mixture, showed that urea when mixed with each molluscicides showed greatly reduced on the growth rate percent (0.00), survival rate and snail fecundity. Molluscicides and fertilizers mixed at different ratios of LC (40:10, 30:20, 25:25, 20:30 & 10:40), the toxicity of the mixtures caused antagonistic effect on adult B. alexandrina, but a mixture of niclosamide-ammonium nitrate caused a potent effect (synergism or additive) except at ratio 20:30 which showed an antagonism on L. natalensis. Mixtures of copper sulphatepotassium sulphate (10:40), niclosamide-potassium sulphate (20:30), mollutox-ammonium nitrate (25:25) revealed an additive effect on L. natalensis.

  10. Erosion and abrasion-inhibiting in situ effect of the Euclea natalensis plant of African regions.

    PubMed

    Sales-Peres, Silvia Helena de Carvalho; Xavier, Cheila Nilza Hamina; Mapengo, Marta Artemisa Abel; Forim, Moacir Rossi; Silva, Maria de Fatima; Sales-Peres, Arsenio

    2016-06-14

    This study evaluated the effect of Euclea natalensis gel on the reduction of erosive wear with or without abrasion, in enamel and dentin. During two five-day experimental crossover phases, volunteers (n = 10) wore palatal devices containing human enamel and dentin blocks (E = 8 and D = 8). The gel was applied in a thin layer in the experimental group, and was not applied in the control group. In the intraoral phase, volunteers used the palatal appliance for 12 h before the gel treatment, and were instructed to start the erosive challenges 6 h after the gel application. Erosion was performed with Coca-Cola® (for 5 min) 4 times/day. The appliance was then put back into the mouth and was brushed after 30 minutes. After intraoral exposure, the appliances were removed and the specimens were analyzed using profilometry (mean ± SD, μm). The Euclea natalensis gel caused less wear in enamel in the experimental group (EROS = 12.86 ± 1.75 µm; EROS + ABRAS = 12.13 ± 2.12 µm) than in the control group (EROS = 14.12 ± 7.66 µm; EROS + ABRAS = 16.29 ± 10.72 µm); however, the groups did not differ from each other significantly. A statistically significant value was found for erosion and eros + abrasion in dentin (p = 0.001). Euclea natalensis may play a role in the prevention of dentin loss under mild erosive and abrasive conditions. A clinical trial is required to confirm these promising results in a clinical situation. PMID:27305512

  11. Erosion and abrasion-inhibiting in situ effect of the Euclea natalensis plant of African regions.

    PubMed

    Sales-Peres, Silvia Helena de Carvalho; Xavier, Cheila Nilza Hamina; Mapengo, Marta Artemisa Abel; Forim, Moacir Rossi; Silva, Maria de Fatima; Sales-Peres, Arsenio

    2016-06-14

    This study evaluated the effect of Euclea natalensis gel on the reduction of erosive wear with or without abrasion, in enamel and dentin. During two five-day experimental crossover phases, volunteers (n = 10) wore palatal devices containing human enamel and dentin blocks (E = 8 and D = 8). The gel was applied in a thin layer in the experimental group, and was not applied in the control group. In the intraoral phase, volunteers used the palatal appliance for 12 h before the gel treatment, and were instructed to start the erosive challenges 6 h after the gel application. Erosion was performed with Coca-Cola® (for 5 min) 4 times/day. The appliance was then put back into the mouth and was brushed after 30 minutes. After intraoral exposure, the appliances were removed and the specimens were analyzed using profilometry (mean ± SD, μm). The Euclea natalensis gel caused less wear in enamel in the experimental group (EROS = 12.86 ± 1.75 µm; EROS + ABRAS = 12.13 ± 2.12 µm) than in the control group (EROS = 14.12 ± 7.66 µm; EROS + ABRAS = 16.29 ± 10.72 µm); however, the groups did not differ from each other significantly. A statistically significant value was found for erosion and eros + abrasion in dentin (p = 0.001). Euclea natalensis may play a role in the prevention of dentin loss under mild erosive and abrasive conditions. A clinical trial is required to confirm these promising results in a clinical situation.

  12. Streptomyces natalensis programmed cell death and morphological differentiation are dependent on oxidative stress

    PubMed Central

    Beites, Tiago; Oliveira, Paulo; Rioseras, Beatriz; Pires, Sílvia D. S.; Oliveira, Rute; Tamagnini, Paula; Moradas-Ferreira, Pedro; Manteca, Ángel; Mendes, Marta V.

    2015-01-01

    Streptomyces are aerobic Gram-positive bacteria characterized by a complex life cycle that includes hyphae differentiation and spore formation. Morphological differentiation is triggered by stressful conditions and takes place in a pro-oxidant environment, which sets the basis for an involvement of the oxidative stress response in this cellular process. Characterization of the phenotypic traits of Streptomyces natalensis ΔkatA1 (mono-functional catalase) and ΔcatR (Fur-like repressor of katA1 expression) strains in solid medium revealed that both mutants had an impaired morphological development process. The sub-lethal oxidative stress caused by the absence of KatA1 resulted in the formation of a highly proliferative and undifferentiated vegetative mycelium, whereas de-repression of CatR regulon, from which KatA1 is the only known representative, resulted in the formation of scarce aerial mycelium. Both mutant strains had the transcription of genes associated with aerial mycelium formation and biosynthesis of the hyphae hydrophobic layer down-regulated. The first round of the programmed cell death (PCD) was inhibited in both strains which caused the prevalence of the transient primary mycelium (MI) over secondary mycelium (MII). Our data shows that the first round of PCD and morphological differentiation in S. natalensis is dependent on oxidative stress in the right amount at the right time. PMID:26256439

  13. Crosstalk between ROS Homeostasis and Secondary Metabolism in S. natalensis ATCC 27448: Modulation of Pimaricin Production by Intracellular ROS

    PubMed Central

    Santos, Catarina L.; Osório, Hugo; Moradas-Ferreira, Pedro; Mendes, Marta V.

    2011-01-01

    Streptomyces secondary metabolism is strongly affected by oxygen availability. The increased culture aeration enhances pimaricin production in S. natalensis, however the excess of O2 consumption can lead to an intracellular ROS imbalance that is harmful to the cell. The adaptive physiological response of S. natalensis upon the addition of exogenous H2O2 suggested that the modulation of the intracellular ROS levels, through the activation of the H2O2 inducible catalase during the late exponential growth phase, can alter the production of pimaricin. With the construction of defective mutants on the H2O2 related enzymes SodF, AhpCD and KatA1, an effective and enduring modulation of intracellular ROS was achieved. Characterization of the knock-out strains revealed different behaviours regarding pimaricin production: whilst the superoxide dismutase defective mutant presented low levels of pimaricin production compared to the wild-type, the mutants defective on the H2O2-detoxifying enzymes displayed a pimaricin overproducer phenotype. Using physiological and molecular approaches we report a crosstalk between oxidative stress and secondary metabolism regulatory networks. Our results reveal that the redox-based regulation network triggered by an imbalance of the intracellular ROS homeostasis is also able to modulate the biosynthesis of pimaricin in S. natalensis. PMID:22114674

  14. Development of cycad ovules and seeds. 2. Histological and ultrastructural aspects of ontogeny of the embryo in Encephalartos natalensis (Zamiaceae).

    PubMed

    Woodenberg, Wynston Ray; Berjak, Patricia; Pammenter, N W; Farrant, Jill M

    2014-07-01

    Development of the embryo of Encephalartos natalensis from a rudimentary meristematic structure approximately 700 μm in length extends over 6 months after the seed is shed from the strobilus. Throughout its development, the embryo remains attached to a long suspensor. Differentiation of the shoot meristem flanked by two cotyledonary protuberances occurs over the first 2 months, during which peripheral tannin channels become apparent. Tannins, apparently elaborated by the endoplasmic reticulum, first accumulate in the large central vacuole and ultimately fill the channel. By the fourth month of development, the root meristem is apparent and procambial tissue forming discrete vascular bundles can be discerned in the elongating cotyledons. Between 4 and 6 months, mucilage ducts differentiate; after 6 months, when the seed becomes germinable, the embryo is characterised by cotyledons far longer than the axis. Shoot and root meristem cells remain ultrastructurally similar throughout embryo ontogeny, containing small vacuoles, many well-differentiated mitochondria and endoplasmic reticulum (ER) profiles, abundant polysomes, plastids containing small starch deposits and Golgi bodies. Unusually, however, Golgi bodies are infrequent in other cells including those elaborating mucilage which is accumulated in distended ER and apparently secreted into the duct lumen directly by ER-derived vesicles. The non-meristematic cells accumulate massive starch deposits to the exclusion of any protein bodies and only very sparse lipid, features which are considered in terms of the prolonged period of embryo development and the high atmospheric oxygen content of the Carboniferous Period, when cycads are suggested to have originated.

  15. Characterization of the polyene macrolide P450 epoxidase from Streptomyces natalensis that converts de-epoxypimaricin into pimaricin

    PubMed Central

    2004-01-01

    The biosynthesis of the antifungal agent pimaricin by Streptomyces natalensis has been proposed to involve a cytochrome P450 encoded by the gene pimD. Pimaricin is derived from its immediate precursor de-epoxypimaricin by epoxidation of the C-4–C-5 double bond on the macrolactone ring. We have overproduced PimD with a N-terminal His6 affinity tag in Escherichia coli and purified the enzyme for kinetic analysis. The protein showed a reduced CO-difference spectrum with a Soret maximum at 450 nm, indicating that it is a cytochrome P450. Purified PimD was shown to catalyse the in vitro C-4–C-5 epoxidation of 4,5-de-epoxypimaricin to pimaricin. The enzyme was dependent on NADPH for activity with optimal pH at 7.5, and the temperature optimum was 30 °C. The kcat value for the epoxidation of de-epoxypimaricin was similar to the values reported for other macrolide oxidases. Enzyme activity was inhibited at high substrate concentration. This is the first time that a polyene macrolide P450 mono-oxygenase has been expressed heterologously and studied. The unique specificity of this epoxidase should be useful for the oxidative modification of novel polyene macrolide antibiotics. PMID:15228385

  16. Development of cycad ovules and seeds. 2. Histological and ultrastructural aspects of ontogeny of the embryo in Encephalartos natalensis (Zamiaceae).

    PubMed

    Woodenberg, Wynston Ray; Berjak, Patricia; Pammenter, N W; Farrant, Jill M

    2014-07-01

    Development of the embryo of Encephalartos natalensis from a rudimentary meristematic structure approximately 700 μm in length extends over 6 months after the seed is shed from the strobilus. Throughout its development, the embryo remains attached to a long suspensor. Differentiation of the shoot meristem flanked by two cotyledonary protuberances occurs over the first 2 months, during which peripheral tannin channels become apparent. Tannins, apparently elaborated by the endoplasmic reticulum, first accumulate in the large central vacuole and ultimately fill the channel. By the fourth month of development, the root meristem is apparent and procambial tissue forming discrete vascular bundles can be discerned in the elongating cotyledons. Between 4 and 6 months, mucilage ducts differentiate; after 6 months, when the seed becomes germinable, the embryo is characterised by cotyledons far longer than the axis. Shoot and root meristem cells remain ultrastructurally similar throughout embryo ontogeny, containing small vacuoles, many well-differentiated mitochondria and endoplasmic reticulum (ER) profiles, abundant polysomes, plastids containing small starch deposits and Golgi bodies. Unusually, however, Golgi bodies are infrequent in other cells including those elaborating mucilage which is accumulated in distended ER and apparently secreted into the duct lumen directly by ER-derived vesicles. The non-meristematic cells accumulate massive starch deposits to the exclusion of any protein bodies and only very sparse lipid, features which are considered in terms of the prolonged period of embryo development and the high atmospheric oxygen content of the Carboniferous Period, when cycads are suggested to have originated. PMID:24240517

  17. New Hosts of The Lassa Virus.

    PubMed

    Olayemi, Ayodeji; Cadar, Daniel; Magassouba, N'Faly; Obadare, Adeoba; Kourouma, Fode; Oyeyiola, Akinlabi; Fasogbon, Samuel; Igbokwe, Joseph; Rieger, Toni; Bockholt, Sabrina; Jérôme, Hanna; Schmidt-Chanasit, Jonas; Garigliany, Mutien; Lorenzen, Stephan; Igbahenah, Felix; Fichet, Jean-Nicolas; Ortsega, Daniel; Omilabu, Sunday; Günther, Stephan; Fichet-Calvet, Elisabeth

    2016-01-01

    Lassa virus (LASV) causes a deadly haemorrhagic fever in humans, killing several thousand people in West Africa annually. For 40 years, the Natal multimammate rat, Mastomys natalensis, has been assumed to be the sole host of LASV. We found evidence that LASV is also hosted by other rodent species: the African wood mouse Hylomyscus pamfi in Nigeria, and the Guinea multimammate mouse Mastomys erythroleucus in both Nigeria and Guinea. Virus strains from these animals were isolated in the BSL-4 laboratory and fully sequenced. Phylogenetic analyses of viral genes coding for glycoprotein, nucleoprotein, polymerase and matrix protein show that Lassa strains detected in M. erythroleucus belong to lineages III and IV. The strain from H. pamfi clusters close to lineage I (for S gene) and between II &III (for L gene). Discovery of new rodent hosts has implications for LASV evolution and its spread into new areas within West Africa. PMID:27140942

  18. New Hosts of The Lassa Virus

    PubMed Central

    Olayemi, Ayodeji; Cadar, Daniel; Magassouba, N’Faly; Obadare, Adeoba; Kourouma, Fode; Oyeyiola, Akinlabi; Fasogbon, Samuel; Igbokwe, Joseph; Rieger, Toni; Bockholt, Sabrina; Jérôme, Hanna; Schmidt-Chanasit, Jonas; Garigliany, Mutien; Lorenzen, Stephan; Igbahenah, Felix; Fichet, Jean-Nicolas; Ortsega, Daniel; Omilabu, Sunday; Günther, Stephan; Fichet-Calvet, Elisabeth

    2016-01-01

    Lassa virus (LASV) causes a deadly haemorrhagic fever in humans, killing several thousand people in West Africa annually. For 40 years, the Natal multimammate rat, Mastomys natalensis, has been assumed to be the sole host of LASV. We found evidence that LASV is also hosted by other rodent species: the African wood mouse Hylomyscus pamfi in Nigeria, and the Guinea multimammate mouse Mastomys erythroleucus in both Nigeria and Guinea. Virus strains from these animals were isolated in the BSL-4 laboratory and fully sequenced. Phylogenetic analyses of viral genes coding for glycoprotein, nucleoprotein, polymerase and matrix protein show that Lassa strains detected in M. erythroleucus belong to lineages III and IV. The strain from H. pamfi clusters close to lineage I (for S gene) and between II & III (for L gene). Discovery of new rodent hosts has implications for LASV evolution and its spread into new areas within West Africa. PMID:27140942

  19. Immunization with Wuchereria bancrofti Glutathione-S-transferase Elicits a Mixed Th1/Th2 Type of Protective Immune Response Against Filarial Infection in Mastomys.

    PubMed

    Andure, Dhananjay; Pote, Kiran; Khatri, Vishal; Amdare, Nitin; Padalkar, Ramchandra; Reddy, Maryada Venkata Rami

    2016-10-01

    Lymphatic filariasis is a mosquito borne parasitic infection and can severely affect the normal working ability of an individual. Currently there is no vaccine available to prevent this infection and the development of a potential vaccine could effectively support the on-going mass drug administration program by World Health Organization (WHO). Filarial parasites have complex mechanisms to modulate the host immune responses against them. The glutathione-S-transferases (GST) are the important enzymes effectively involved to counteract the oxidative free radicals produced by the host. In the present study, we have shown that the mastomys which are fully permissible rodents for Brugia malayi when immunized with Wuchereria bancrofti recombinant GST (rWbGST) could induce 65.5 % in situ cytotoxicity against B. malayi infective (L3) larvae. There was a balanced Th1/Th2 immune response in the vaccinated animals, characterized by higher levels of WbGST-specific IgG1 and IgG2a antibodies and pronounced IFN-γ, IL-10 and IL-4 cytokines production by the spleen cells. PMID:27605739

  20. Rat-atouille: A Mixed Method Study to Characterize Rodent Hunting and Consumption in the Context of Lassa Fever.

    PubMed

    Bonwitt, Jesse; Kelly, Ann H; Ansumana, Rashid; Agbla, Schadrac; Sahr, Foday; Saez, Almudena Mari; Borchert, Matthias; Kock, Richard; Fichet-Calvet, Elisabeth

    2016-06-01

    Lassa fever is a zoonotic hemorrhagic illness predominant in areas across Nigeria, Sierra Leone, Guinea, Liberia, and southern Mali. The reservoir of Lassa virus is the multimammate mouse (Mastomys natalensis), a highly commensal species in West Africa. Primary transmission to humans occurs through direct or indirect contact with rodent body fluids such as urine, feces, saliva, or blood. Our research draws together qualitative and quantitative methods to provide a fuller and more nuanced perspective on these varied points of human-animal contact. In this article, we focus on the hunting, preparation, and consumption of rodents as possible routes of exposure in Bo, Sierra Leone. We found that the consumption of rodents, including the reservoir species, is widespread and does not neatly tally against generational or gender lines. Further, we found that the reasons for rodent consumption are multifactorial, including taste preferences, food security, and opportunistic behavior. We argue that on certain topics, such as rodent consumption, establishing trust with communities, and using qualitative research methods, is key to investigate sensitive issues and situate them in their wider context. To conclude, we recommend ways to refine sensitization campaigns to account for these socio-cultural contexts. PMID:26895631

  1. Fasciola gigantica: cercarial shedding pattern from Lymnaea natalensis after long-term exposure to cadmium at different temperatures.

    PubMed

    Soliman, Maha F M

    2009-04-01

    Little is known about the response of Fasciola spp., inside its snail host to pollutant toxicity. The effect of long-term exposure of Lymnaea natalensis to 0.1 microg/l, 10 microg/l, or 100 microg/l cadmium (Cd) on the infection rates with F. gigantica, percentage of cercariae-shedding snails and cercariae shedding pattern was investigated. The snails were exposed to Cd for 7 days either pre-infection with single Fasciola miracidium or during the late pre-patent period of the infection. The possible interaction between metal exposure and acclimatization temperature was also studied in three ranges; 16-18 degrees C, 23-25 degrees C and 30-32 degrees C. Results clearly showed that host exposure to 100 microg/l Cd significantly affected the pattern of Fasciola development inside its snail host, and that the acclimatization temperature was a key factor affecting the role played by Cd. Pre-infection exposure to Cd caused a significant reduction in the infection rates where the effect was temperature-dependent. Post-infection exposure to Cd significantly increased the percentage of cercariae-shedding snails; the effect was temperature-independent. Interestingly, post-infection exposure significantly altered the differential cercarial output pattern, while no clear impact on the total was found. The alteration in the differential cercarial output was represented as a significantly higher proportion of floating metacercaria as compared to fixed ones and also higher proportion of dead cercariae which may directly reduce the transmission of Fasciola to the final host. The mechanisms of cadmium impact are briefly discussed. PMID:19101545

  2. Uptake and distribution of copper sulfate and its effect on the respiration rate of the hemocyanin-producing freshwater snail Lymnaea natalensis

    SciTech Connect

    Wolmarans, C.T.; Yssel, E.

    1988-08-01

    Copper sulfate was one of the earliest compounds suggested as a molluscicide and although several new compounds have since been developed, copper sulfate is still widely used against freshwater snail intermediate hosts of trematode parasites causing bilharzia. However, the toxic effect that copper sulfate may have on these species has not yet been investigated adequately. This incomplete picture of the action of copper sulfate on freshwater snails is further complicated by the fact that some of these snail species have hemocyanin (a protein containing copper) as respiration pigment. Because of the existence of a copper metabolic pathway, these species may handle external copper differently from those species with hemoglobin as respiration pigment. In the present study, the uptake of external copper in the form of copper sulfate, as well as the effect of this ion on respiration rate, was investigated in Lymnaea natalensis, the intermediate host of Fasciola gigantica. This snail possesses hemocyanin as respiratory pigment.

  3. Observations on a lesser-known monogenean, Udonella myliobati, from a copepod parasite, Lepeophtheirus natalensis, parasitizing the spotted ragged-tooth shark, Carcharias taurus, from South African waters.

    PubMed

    Olivier, P A; Dippenaar, S M; Khalil, L F; Mokgalong, N M

    2000-06-01

    The phylogeny of the genus Udonella has been disputed for quite some time, but recent phylogenetic analysis of molecular data confirms that the genus is a monopisthocotylean monogenean. Specimens of Udonella myliobati parasitizing the copepod Lepeophtheirus natalensis, an ectoparasite of the spotted ragged-tooth shark, (Carcharias taurus), were collected and studied. A total of 771 monogenean specimens were recovered from 54 infected copepods examined, with a mean intensity of 14,3 worms per copepod. Most of the monogeneans were found attached to the dorsal surface of the lateral and frontal marginal membranes of the copepod carapace. Eggs, with filaments and adhesive discs, were found ventrally on the host, mainly attached to the maxillae and maxillipeds, in clusters of 12-14. Observations on the morphology, distribution and behaviour of this monogenean are presented with the aid of light and scanning electron microscopy.

  4. Sequence variability and geographic distribution of Lassa virus, Sierra Leone.

    PubMed

    Leski, Tomasz A; Stockelman, Michael G; Moses, Lina M; Park, Matthew; Stenger, David A; Ansumana, Rashid; Bausch, Daniel G; Lin, Baochuan

    2015-04-01

    Lassa virus (LASV) is endemic to parts of West Africa and causes highly fatal hemorrhagic fever. The multimammate rat (Mastomys natalensis) is the only known reservoir of LASV. Most human infections result from zoonotic transmission. The very diverse LASV genome has 4 major lineages associated with different geographic locations. We used reverse transcription PCR and resequencing microarrays to detect LASV in 41 of 214 samples from rodents captured at 8 locations in Sierra Leone. Phylogenetic analysis of partial sequences of nucleoprotein (NP), glycoprotein precursor (GPC), and polymerase (L) genes showed 5 separate clades within lineage IV of LASV in this country. The sequence diversity was higher than previously observed; mean diversity was 7.01% for nucleoprotein gene at the nucleotide level. These results may have major implications for designing diagnostic tests and therapeutic agents for LASV infections in Sierra Leone.

  5. Sequence Variability and Geographic Distribution of Lassa Virus, Sierra Leone

    PubMed Central

    Stockelman, Michael G.; Moses, Lina M.; Park, Matthew; Stenger, David A.; Ansumana, Rashid; Bausch, Daniel G.; Lin, Baochuan

    2015-01-01

    Lassa virus (LASV) is endemic to parts of West Africa and causes highly fatal hemorrhagic fever. The multimammate rat (Mastomys natalensis) is the only known reservoir of LASV. Most human infections result from zoonotic transmission. The very diverse LASV genome has 4 major lineages associated with different geographic locations. We used reverse transcription PCR and resequencing microarrays to detect LASV in 41 of 214 samples from rodents captured at 8 locations in Sierra Leone. Phylogenetic analysis of partial sequences of nucleoprotein (NP), glycoprotein precursor (GPC), and polymerase (L) genes showed 5 separate clades within lineage IV of LASV in this country. The sequence diversity was higher than previously observed; mean diversity was 7.01% for nucleoprotein gene at the nucleotide level. These results may have major implications for designing diagnostic tests and therapeutic agents for LASV infections in Sierra Leone. PMID:25811712

  6. Poor housing quality increases risk of rodent infestation and Lassa fever in refugee camps of Sierra Leone.

    PubMed

    Bonner, Phillip Cullison; Schmidt, Wolf-Peter; Belmain, Steven R; Oshin, Babafemi; Baglole, Debbie; Borchert, Matthias

    2007-07-01

    Lassa fever, a viral hemorrhagic fever endemic in parts of West Africa, is a severe febrile illness transmitted to humans by the rodent Mastomys natalensis. To determine risk of Lassa fever in households in Sierra Leonean refugee camps, we analyzed the spatial relationships between households with a Lassa case and focal locations of potential rodent habitats. Quality and hygiene factors of households were assessed to determine possible risk factors for household rodent infestation and occurrence of Lassa fever. The odds to have a rat burrow were higher in case houses than in control houses (OR 24, 95% CI 6.0-93). Case houses scored significantly worse in the quality of housing and external hygiene. These findings suggest that risk of Lassa fever in refugee camps depends on individual housing quality and the hygiene of the immediate surrounding environment.

  7. Small mammals as hosts of immature ixodid ticks.

    PubMed

    Horak, I G; Fourie, L J; Braack, L E O

    2005-09-01

    Two hundred and twenty-five small mammals belonging to 16 species were examined for ticks in Free State, Mpumalanga and Limpopo Provinces, South Africa, and 18 ixodid tick species, of which two could only be identified to genus level, were recovered. Scrub hares, Lepus saxatilis, and Cape hares, Lepus capensis, harboured the largest number of tick species. In Free State Province Namaqua rock mice, Aethomys namaquensis, and four-striped grass mice, Rhabdomys pumilio, were good hosts of the immature stages of Haemaphysalis leachi and Rhipicephalus gertrudae, while in Mpumalanga and Limpopo Provinces red veld rats, Aethomys chrysophilus, Namaqua rock mice and Natal multimammate mice, Mastomys natalensis were good hosts of H. leachi and Rhipicephalus simus. Haemaphysalis leachi was the only tick recovered from animals in all three provinces.

  8. Lassa Serology in Natural Populations of Rodents and Horizontal Transmission

    PubMed Central

    Becker-Ziaja, Beate; Koivogui, Lamine; Günther, Stephan

    2014-01-01

    Abstract Lassa virus causes hemorrhagic fever in West Africa. Previously, we demonstrated by PCR screening that only the multimammate mouse, Mastomys natalensis, hosts Lassa virus in Guinea. In the present study, we used the same specimen collection from 17 villages in Coastal, Upper, and Forest Guinea to investigate the Lassa virus serology in the rodent population. The aim was to determine the dynamics of antibody development in M. natalensis and to detect potential spillover infections in other rodent species. Immunoglobulin G (IgG) antibody screening was performed using the indirect immunofluorescence assay with the Guinean Lassa virus strain Bantou 289 as antigen. The overall seroprevalence was 8% (129/1551) with the following rodents testing positive: 109 M. natalensis, seven Mastomys erythroleucus, four Lemniscomys striatus, four Praomys daltoni, three Mus minutoides, and two Praomys rostratus. Nearly all of them (122/129) originated from Bantou, Tanganya, and Gbetaya, where Lassa virus is highly endemic in M. natalensis. The antibody seroprevalence in M. natalensis from this high-endemic area (27%; 108/396) depended on the village, habitat, host age, and host abundance. A main positive factor was age; the maximum seroprevalence reached 50% in older animals. Our data fit with a model implicating that most M. natalensis rodents become horizontally infected, clear the virus within a period significantly shorter than their life span, and develop antibodies. In addition, the detection of antibodies in other species trapped in the habitats of M. natalensis suggests spillover infections. PMID:25229705

  9. Novel Arenavirus, Zambia

    PubMed Central

    Thomas, Yuka; Moonga, Ladslav; Nakamura, Ichiro; Ohnuma, Aiko; Hang’ombe, Bernard; Takada, Ayato; Mweene, Aaron; Sawa, Hirofumi

    2011-01-01

    To investigate arenavirus in Zambia, we characterized virus from the kidneys of 5 arenavirus RNA–positive rodents (Mastomys natalensis) among 263 captured. Full-genome sequences of the viruses suggested that they were new strains similar to Lassa virus–related arenaviruses. Analyzing samples from additional rodents and other species can elucidate epizootiologic aspects of arenaviruses. PMID:22000372

  10. μ-Theraphotoxin-An1a: primary structure determination and assessment of the pharmacological activity of a promiscuous anti-insect toxin from the venom of the tarantula Acanthoscurria natalensis (Mygalomorphae, Theraphosidae).

    PubMed

    Rates, Breno; Prates, Maura V; Verano-Braga, Thiago; da Rocha, Angela P; Roepstorff, Peter; Borges, Carlos L; Lapied, Bruno; Murillo, Laurence; Pimenta, Adriano M C; Biondi, Ilka; De Lima, Maria Elena

    2013-08-01

    Tarantulas are included in the mygalomorph spider family Theraphosidae. Although the pharmacological diversity of theraphosid toxins (theraphotoxins) is broad, studies dedicated to the characterization of biologically active molecules from the theraphosid genus Acanthoscurria have been restricted to the investigation of antimicrobial peptides and polyamines produced by the hemocytes of Acanthoscurria gomesiana. The present study reports the purification, primary structure determination and electrophysiological effects of an anti-insect toxin, named μ-theraphotoxin-An1a (μ-TRTX-An1a), from the venom of Acanthoscurria natalensis - a tarantula species occurring in the Brazilian biomes caatinga and cerrado. The analysis of the primary structure of μ-TRTX-An1a revealed the similarity of this toxin to theraphosid toxins bearing a huwentoxin-II-like fold. Electrophysiological experiments showed that μ-TRTX-An1a (100 nM) induces membrane depolarization, increases the spontaneous firing frequency and reduces spike amplitude of cockroach dorsal unpaired median (DUM) neurons. In addition, under voltage-clamp conditions, μ-TRTX-An1a (100 nM) only partially blocks voltage-dependent sodium current amplitudes in DUM neurons without any effect on their voltage dependence. This effect correlates well with the reduction of the spontaneous action potential amplitudes. Altogether, these last results suggest that μ-TRTX-An1a affects insect neuronal voltage-dependent sodium channels, which are among possible channels targeted by this promiscuous toxin. PMID:23651762

  11. The effect of diethylcarbamazine on microfilariae of Litomosoides carinii in vitro and in vivo.

    PubMed

    Weiner, D J; Abraham, D; D'Antonio, R

    1986-01-01

    Culture-derived Litomosoides carinii microfilariae (MFF) were used in in vitro and in vivo systems to investigate the effect of diethylcarbamazine (DEC) on these MFF. In vivo: Male rats, Mastomys natalensis, all of the same age, were injected intrathoracically (12) or intraperitoneally (36) with 10(3) or 10(4) MFF. After 30 min one half of each group of rats was given DEC per os. At 30, 60, and 120 min after DEC administration, two rats from the treated and two from the untreated group were bled and killed. The pleural or peritoneal cavities were rinsed with warm saline (0.15 M NaCl) to recover MFF. In both the intrathoracic and intraperitoneal experiments, equal numbers of MFF were recovered from treated and control rats at 30 and 120 min. However, at 60 min 85.5% fewer were recovered from the treated than from the nontreated animals. MFF were not found in the blood. In vitro: MFF were added to tissue culture dish wells (Linbro Div., Flow Labs, Hamden, Conn) prepared as follows: DEC-Serum (serum from normal rats given DEC at 500 mg/kg), DEC + Serum (serum with added DEC), serum only, RPMI 1640 only, and RPMI 1640 + DEC. Furthermore, the five treatments were prepared either with or without unstimulated peritoneal exudate (PE) cells. At 30 min in the DEC-Serum wells 45% of the MFF had adherent PE cells; in the remaining wells these cells adhered to 11% or fewer MFF. We interpret the aforementioned phenomena as representing the first step in the trapping and elimination of MFF after DEC treatment of L. carinii-infected M. natalensis. PMID:3799010

  12. Housing equity for health equity: a rights-based approach to the control of Lassa fever in post-war Sierra Leone.

    PubMed

    Kelly, J Daniel; Barrie, M Bailor; Ross, Rachel A; Temple, Brian A; Moses, Lina M; Bausch, Daniel G

    2013-01-01

    Poor quality housing is an infringement on the rights of all humans to a standard of living adequate for health. Among the many vulnerabilities of those without adequate shelter is the risk of disease spread by rodents and other pests. One such disease is Lassa fever, an acute and sometimes severe viral hemorrhagic illness endemic in West Africa. Lassa virus is maintained in the rodent Mastomys natalensis, commonly known as the "multimammate rat," which frequently invades the domestic environment, putting humans at risk of Lassa fever. The highest reported incidence of Lassa fever in the world is consistently in the Kenema District of Sierra Leone, a region that was at the center of Sierra Leone's civil war in which tens of thousands of lives were lost and hundreds of thousands of dwellings destroyed. Despite the end of the war in 2002, most of Kenema's population still lives in inadequate housing that puts them at risk of rodent invasion and Lassa fever. Furthermore, despite years of health education and village hygiene campaigns, the incidence of Lassa fever in Kenema District appears to be increasing. We focus on Lassa fever as a matter of human rights, proposing a strategy to improve housing quality, and discuss how housing equity has the potential to improve health equity and ultimately economic productivity in Sierra Leone. The manuscript is designed to spur discussion and action towards provision of housing and prevention of disease in one of the world's most vulnerable populations. PMID:23282054

  13. Housing equity for health equity: a rights-based approach to the control of Lassa fever in post-war Sierra Leone.

    PubMed

    Kelly, J Daniel; Barrie, M Bailor; Ross, Rachel A; Temple, Brian A; Moses, Lina M; Bausch, Daniel G

    2013-01-02

    Poor quality housing is an infringement on the rights of all humans to a standard of living adequate for health. Among the many vulnerabilities of those without adequate shelter is the risk of disease spread by rodents and other pests. One such disease is Lassa fever, an acute and sometimes severe viral hemorrhagic illness endemic in West Africa. Lassa virus is maintained in the rodent Mastomys natalensis, commonly known as the "multimammate rat," which frequently invades the domestic environment, putting humans at risk of Lassa fever. The highest reported incidence of Lassa fever in the world is consistently in the Kenema District of Sierra Leone, a region that was at the center of Sierra Leone's civil war in which tens of thousands of lives were lost and hundreds of thousands of dwellings destroyed. Despite the end of the war in 2002, most of Kenema's population still lives in inadequate housing that puts them at risk of rodent invasion and Lassa fever. Furthermore, despite years of health education and village hygiene campaigns, the incidence of Lassa fever in Kenema District appears to be increasing. We focus on Lassa fever as a matter of human rights, proposing a strategy to improve housing quality, and discuss how housing equity has the potential to improve health equity and ultimately economic productivity in Sierra Leone. The manuscript is designed to spur discussion and action towards provision of housing and prevention of disease in one of the world's most vulnerable populations.

  14. Stochastic seasonality and nonlinear density-dependent factors regulate population size in an African rodent

    USGS Publications Warehouse

    Leirs, H.; Stenseth, N.C.; Nichols, J.D.; Hines, J.E.; Verhagen, R.; Verheyen, W.

    1997-01-01

    Ecology has long been troubled by the controversy over how populations are regulated. Some ecologists focus on the role of environmental effects, whereas others argue that density-dependent feedback mechanisms are central. The relative importance of both processes is still hotly debated, but clear examples of both processes acting in the same population are rare. Keyfactor analysis (regression of population changes on possible causal factors) and time-series analysis are often used to investigate the presence of density dependence, but such approaches may be biased and provide no information on actual demographic rates. Here we report on both density-dependent and density-independent effects in a murid rodent pest species, the multimammate rat Mastomys natalensis (Smith, 1834), using statistical capture-recapture models. Both effects occur simultaneously, but we also demonstrate that they do not affect all demographic rates in the same way. We have incorporated the obtained estimates of demographic rates in a population dynamics model and show that the observed dynamics are affected by stabilizing nonlinear density-dependent components coupled with strong deterministic and stochastic seasonal components.

  15. Evaluation of demographic parameters of native rodent populations and implications for control

    PubMed Central

    French, Norman R.

    1975-01-01

    The ecology of the multimammate mouse ,Mastomys natalensis, is reviewed and approximations are derived for the parameters governing population growth. By means of computer simulation, the relative importance of the timing of reproduction, the age class distribution or age structure of the population, the competition between Mastomys and Rattus, and the interaction with a predator are evaluated. Although each of these demographic or ecological factors modifies the fate of the Mastomys population, the greatest single impact results from a reproductive season that is divided into two parts rather than a single continuous reproductive season. Division into two parts, correlated with a similar distribution of rainfall, allows time for maturing of the young born early in the season and for production of young by them, thus adding to the momentum of population increase. The interaction of density-dependent factors controlling population growth, competition with another rodent, or predation by a Viverrid predator, may increase the growth rate of the Mastomys population or may depress population growth rate, even to the point of extinction. These simulation studies demonstrate the necessity for critical evaluation of the demographic parameters and ecological characteristics of a particular Mastomys population before an effective control programme can be designed. They also demonstrate, however, that if the programme is based upon sound ecological theory control can be effected. PMID:1085223

  16. The isotopic ecology of African mole rats informs hypotheses on the evolution of human diet.

    PubMed

    Yeakel, Justin D; Bennett, Nigel C; Koch, Paul L; Dominy, Nathaniel J

    2007-07-22

    The diets of Australopithecus africanus and Paranthropus robustus are hypothesized to have included C4 plants, such as tropical grasses and sedges, or the tissues of animals which themselves consumed C4 plants. Yet inferences based on the craniodental morphology of A. africanus and P. robustus indicate a seasonal diet governed by hard, brittle foods. Such mechanical characteristics are incompatible with a diet of grasses or uncooked meat, which are too tough for efficient mastication by flat, low-cusped molars. This discrepancy, termed the C4 conundrum, has led to the speculation that C4 plant underground storage organs (USOs) were a source of nutrition for hominin species. We test this hypothesis by examining the isotopic ecology of African mole rats, which consume USOs extensively. We measured delta18O and delta13C of enamel and bone apatite from fossil and modern species distributed across a range of habitats. We show that delta18O values vary little and that delta13C values vary along the C3 to C4/CAM-vegetative axis. Relatively high delta13C values exist in modern Cryptomys hottentotus natalensis and Cryptomys spp. recovered from hominin-bearing deposits. These values overlap those reported for A. africanus and P. robustus and we conclude that the USO hypothesis for hominin diets retains certain plausibility.

  17. Rats! Oh No, Not Rats!

    ERIC Educational Resources Information Center

    Strong, Gary E.

    1987-01-01

    Examples of problems encountered in a new library building--including rats and humidity--and a description of the library's collections provide a framework for this presentation of the California State Library's emergency management planning. Current preservation efforts are documented and the library's disaster and security plans are described.…

  18. Rat Bite Fever

    MedlinePlus

    ... Issues Listen Español Text Size Email Print Share Rat Bite Fever Page Content Article Body Rat-bite fever is a disease that occurs in humans who have been bitten by an infected rat or, in some cases, squirrels, mice, cats, and ...

  19. Beyond knockout rats

    PubMed Central

    Huang, Guanyi; Tong, Chang; Kumbhani, Dhruv S; Ashton, Charles; Yan, Hexin

    2011-01-01

    The ability to “knockout” specific genes in mice via embryonic stem (ES) cell-based gene-targeting technology has significantly enriched our understanding of gene function in normal and disease phenotypes. Improvements on this original strategy have been developed to enable the manipulation of genomes in a more sophisticated fashion with unprecedented precision. The rat is the model of choice in many areas of scientific investigation despite the lack of rat genetic toolboxes. Most recent advances of zinc finger nucleases (ZFNs) and rat ES cells are diminishing the gap between rat and mouse with respect to reverse genetic approaches. Importantly, the establishment of rat ES cell-based gene targeting technology, in combination with the unique advantages of using rats, provides new, exciting opportunities to create animal models that mimic human diseases more faithfully. We hereby report our recent results concerning finer genetic modifications in the rat, and propose their potential applications in addressing biological questions. PMID:21383544

  20. Canine oral papillomavirus genomic sequence: a unique 1.5-kb intervening sequence between the E2 and L2 open reading frames.

    PubMed

    Delius, H; Van Ranst, M A; Jenson, A B; zur Hausen, H; Sundberg, J P

    1994-10-01

    The canine oral papillomavirus (COPV) is associated with oropharyngeal papillomatosis in dogs, coyotes, and wolves. We have determined the complete nucleotide sequence of COPV, the largest of all known PV genomes (8607 bp). The genomic architecture of the COPV genome is similar to that of other PVs except for a unique and large noncoding region of 1.5 kb between the end of the early region (E2) and the beginning of the late region (L2) and a small (345 bp) upstream regulatory region between the end of L1 and the beginning of E6. Although COPV displays a primarily mucosal tropism, the COPV nucleotide sequence showed the highest overall similarity to cutaneous papillomaviruses such as HPV-1, HPV-63, CRPV (cottontail rabbit PV), FdPV (Felis domesticus PV), and MnPV (Mastomys natalensis PV). PMID:8091677

  1. Diversity and habitat association of small mammals in Aridtsy forest, Awi Zone, Ethiopia

    PubMed Central

    BANTIHUN, Getachew; BEKELE, Afework

    2015-01-01

    Here, we conducted a survey to examine the diversity, distribution and habitat association of small mammals from August 2011 to February 2012 incorporating both wet and dry seasons in Aridtsy forest, Awi Zone, Ethiopia. Using Sherman live traps and snap traps in four randomly selected trapping grids, namely, natural forest, bushland, grassland and farmland, a total of 468 individuals comprising eight species of small mammals (live traps) and 89 rodents of six species (snap traps) were trapped in 2352 and 1200 trap nights, respectively. The trapped small mammals included seven rodents and one insectivore: Lophuromys flavopuntatus (30.6%), Arvicanthis dembeensis (25.8%), Stenocephalemys albipes (20%), Mastomys natalensis (11.6%), Pelomys harringtoni (6.4%), Acomys cahirinus (4.3%), Lemniscomys zebra (0.2%) and the greater red musk shrew (Crocidura flavescens, 1.1%). Analysis showed statistically significant variations in the abundance and habitat preferences of small mammals between habitats during wet and dry seasons. PMID:25855227

  2. Effects of land use on plague (Yersinia pestis) activity in rodents in Tanzania.

    PubMed

    McCauley, Douglas J; Salkeld, Daniel J; Young, Hillary S; Makundi, Rhodes; Dirzo, Rodolfo; Eckerlin, Ralph P; Lambin, Eric F; Gaffikin, Lynne; Barry, Michele; Helgen, Kristofer M

    2015-04-01

    Understanding the effects of land-use change on zoonotic disease risk is a pressing global health concern. Here, we compare prevalence of Yersinia pestis, the etiologic agent of plague, in rodents across two land-use types-agricultural and conserved-in northern Tanzania. Estimated abundance of seropositive rodents nearly doubled in agricultural sites compared with conserved sites. This relationship between land-use type and abundance of seropositive rodents is likely mediated by changes in rodent and flea community composition, particularly via an increase in the abundance of the commensal species, Mastomys natalensis, in agricultural habitats. There was mixed support for rodent species diversity negatively impacting Y. pestis seroprevalence. Together, these results suggest that land-use change could affect the risk of local transmission of plague, and raise critical questions about transmission dynamics at the interface of conserved and agricultural habitats. These findings emphasize the importance of understanding disease ecology in the context of rapidly proceeding landscape change.

  3. Diversity and habitat association of small mammals in Aridtsy forest, Awi Zone, Ethiopia.

    PubMed

    Bantihun, Getachew; Bekele, Afework

    2015-03-18

    Here, we conducted a survey to examine the diversity, distribution and habitat association of small mammals from August 2011 to February 2012 incorporating both wet and dry seasons in Aridtsy forest, Awi Zone, Ethiopia. Using Sherman live traps and snap traps in four randomly selected trapping grids, namely, natural forest, bushland, grassland and farmland, a total of 468 individuals comprising eight species of small mammals (live traps) and 89 rodents of six species (snap traps) were trapped in 2352 and 1200 trap nights, respectively. The trapped small mammals included seven rodents and one insectivore: Lophuromys flavopuntatus (30.6%), Arvicanthis dembeensis (25.8%), Stenocephalemys albipes (20%), Mastomys natalensis (11.6%), Pelomys harringtoni (6.4%), Acomys cahirinus (4.3%), Lemniscomys zebra (0.2%) and the greater red musk shrew (Crocidura flavescens, 1.1%). Analysis showed statistically significant variations in the abundance and habitat preferences of small mammals between habitats during wet and dry seasons.

  4. What is Desert RATS?

    NASA Video Gallery

    The mission manager and test coordinators for the 2011 mission explain why Desert RATS was started 14 years ago, questions being studied in this year's activities, technologies being tested and the...

  5. Anhedonia in postpartum rats.

    PubMed

    Navarre, Brittany M; Laggart, Jillian D; Craft, Rebecca M

    2010-01-12

    Postpartum depression (PPD) is a debilitating illness, yet little is known about its causes. The purpose of this study was to examine a major symptom of depression during the postpartum period, anhedonia, by comparing sucrose preference in female rats that had undergone actual pregnancy or hormone-simulated pregnancy (HSP) to their respective controls. Whereas HSP rats showed significantly less preference than vehicle control rats for 1% sucrose solution during the first three weeks of the "postpartum" period, previously pregnant females showed only slightly depressed sucrose preference for the first 1-2 days postpartum, compared to non-pregnant controls. Habituation to 1% sucrose during the pregnancy period, which increased preference upon later testing in previously pregnant rats tested on postpartum day 2, did not significantly increase preference in HSP rats, suggesting that depressed preference in the latter group was not due to neophobia. Pre-treatment with desipramine did not prevent suppressed sucrose preference in HSP rats, and preference was even further suppressed following chronic sertraline treatment. These results suggest that estradiol withdrawal following HSP may cause anhedonia during the early "postpartum" period. In contrast, females that have undergone actual pregnancy are less likely to show this effect, suggesting that postpartum hormonal changes other than the dramatic decline in estradiol may buffer its negative mood effects.

  6. Landscape determinants of fine-scale genetic structure of a small rodent in a heterogeneous landscape (Hluhluwe-iMfolozi Park, South Africa)

    PubMed Central

    Russo, Isa-Rita M.; Sole, Catherine L.; Barbato, Mario; von Bramann, Ullrich; Bruford, Michael W.

    2016-01-01

    Small mammals provide ecosystem services, acting, for example, as pollinators and seed dispersers. In addition, they are also disease reservoirs that can be detrimental to human health and they can also act as crop pests. Knowledge of their dispersal preferences is therefore useful for population management and landscape planning. Genetic data were used alongside landscape data to examine the influence of the landscape on the demographic connectedness of the Natal multimammate mouse (Mastomys natalensis) and to identify landscape characteristics that influence the genetic structure of this species across a spatially and temporally varying environment. The most significant landscape features shaping gene flow were aspect, vegetation cover, topographic complexity (TC) and rivers, with western facing slopes, topographic complexity and rivers restricting gene flow. In general, thicket vegetation was correlated with increased gene flow. Identifying features of the landscape that facilitate movement/dispersal in M. natalensis potentially has application for other small mammals in similar ecosystems. As the primary reservoir host of the zoonotic Lassa virus, a landscape genetics approach may have applications in determining areas of high disease risk to humans. Identifying these landscape features may also be important in crop management due to damage by rodent pests. PMID:27406468

  7. Landscape determinants of fine-scale genetic structure of a small rodent in a heterogeneous landscape (Hluhluwe-iMfolozi Park, South Africa).

    PubMed

    Russo, Isa-Rita M; Sole, Catherine L; Barbato, Mario; von Bramann, Ullrich; Bruford, Michael W

    2016-01-01

    Small mammals provide ecosystem services, acting, for example, as pollinators and seed dispersers. In addition, they are also disease reservoirs that can be detrimental to human health and they can also act as crop pests. Knowledge of their dispersal preferences is therefore useful for population management and landscape planning. Genetic data were used alongside landscape data to examine the influence of the landscape on the demographic connectedness of the Natal multimammate mouse (Mastomys natalensis) and to identify landscape characteristics that influence the genetic structure of this species across a spatially and temporally varying environment. The most significant landscape features shaping gene flow were aspect, vegetation cover, topographic complexity (TC) and rivers, with western facing slopes, topographic complexity and rivers restricting gene flow. In general, thicket vegetation was correlated with increased gene flow. Identifying features of the landscape that facilitate movement/dispersal in M. natalensis potentially has application for other small mammals in similar ecosystems. As the primary reservoir host of the zoonotic Lassa virus, a landscape genetics approach may have applications in determining areas of high disease risk to humans. Identifying these landscape features may also be important in crop management due to damage by rodent pests.

  8. Landscape determinants of fine-scale genetic structure of a small rodent in a heterogeneous landscape (Hluhluwe-iMfolozi Park, South Africa).

    PubMed

    Russo, Isa-Rita M; Sole, Catherine L; Barbato, Mario; von Bramann, Ullrich; Bruford, Michael W

    2016-01-01

    Small mammals provide ecosystem services, acting, for example, as pollinators and seed dispersers. In addition, they are also disease reservoirs that can be detrimental to human health and they can also act as crop pests. Knowledge of their dispersal preferences is therefore useful for population management and landscape planning. Genetic data were used alongside landscape data to examine the influence of the landscape on the demographic connectedness of the Natal multimammate mouse (Mastomys natalensis) and to identify landscape characteristics that influence the genetic structure of this species across a spatially and temporally varying environment. The most significant landscape features shaping gene flow were aspect, vegetation cover, topographic complexity (TC) and rivers, with western facing slopes, topographic complexity and rivers restricting gene flow. In general, thicket vegetation was correlated with increased gene flow. Identifying features of the landscape that facilitate movement/dispersal in M. natalensis potentially has application for other small mammals in similar ecosystems. As the primary reservoir host of the zoonotic Lassa virus, a landscape genetics approach may have applications in determining areas of high disease risk to humans. Identifying these landscape features may also be important in crop management due to damage by rodent pests. PMID:27406468

  9. Recent isolations of Lassa virus from Nigerian rodents

    PubMed Central

    Wulff, Herta; Fabiyi, A.; Monath, T. P.

    1975-01-01

    Rodents were trapped in the Benue-Plateau and North-Eastern States of Nigeria where Lassa fever had been reported in previous years. Eight Lassa virus strains were isolated from tissues and blood of rodents identified in the field as being of 3 different species: Mastomys natalensis, Rattus rattus, and Mus minutoides. All the infected rodents were collected in village habitats. These isolations indicate the presence of Lassa virus in wild rodents in Nigeria during periods when no human infections were evident. Prior studies in Sierra Leone have indicated that a single rodent species, M. natalensis, may be the important reservoir host of Lassa virus. Since the present study indicates that other rodent species may be involved as well, the ecology of Lassa virus may be more complicated than was heretofore supposed. In view of the importance of determining the geographic and species range of rodent hosts of Lassa virus, and because of the problems inherent in rodent identification under austere field conditions, it is urgent that further studies be conducted in the same areas of Nigeria to confirm these findings. PMID:1085216

  10. Sex-biased parasitism is not universal: evidence from rodent-flea associations from three biomes.

    PubMed

    Kiffner, Christian; Stanko, Michal; Morand, Serge; Khokhlova, Irina S; Shenbrot, Georgy I; Laudisoit, Anne; Leirs, Herwig; Hawlena, Hadas; Krasnov, Boris R

    2013-11-01

    The distribution of parasites among individual hosts is characterised by high variability that is believed to be a result of variations in host traits. To find general patterns of host traits affecting parasite abundance, we studied flea infestation of nine rodent species from three different biomes (temperate zone of central Europe, desert of Middle East and tropics of East Africa). We tested for independent and interactive effects of host sex and body mass on the number of fleas harboured by an individual host while accounting for spatial clustering of host and parasite sampling and temporal variation. We found no consistent patterns of the effect of host sex and body mass on flea abundance either among species within a biome or among biomes. We found evidence for sex-biased flea infestation in just five host species (Apodemus agrarius, Myodes glareolus, Microtus arvalis, Gerbillus andersoni, Mastomys natalensis). In six rodent species, we found an effect of body mass on flea abundance (all species mentioned above and Meriones crassus). This effect was positive in five species and negative in one species (Microtus arvalis). In M. glareolus, G. andersoni, M. natalensis, and M. arvalis, the relationship between body mass and flea abundance was mediated by host sex. This was manifested in steeper change in flea abundance with increasing body mass in male than female individuals (M. glareolus, G. andersoni, M. natalensis), whereas the opposite pattern was found in M. arvalis. Our findings suggest that sex and body mass are common determinants of parasite infestation in mammalian hosts, but neither of them follows universal rules. This implies that the effect of host individual characteristics on mechanisms responsible for flea acquisition may be manifested differently in different host species.

  11. Adrenarche in the rat.

    PubMed

    Pignatelli, Duarte; Xiao, Fang; Gouveia, Alexandra M; Ferreira, Jorge G; Vinson, Gavin P

    2006-10-01

    Normal pubertal development in humans involves two distinct processes: maturation of adrenal androgen secretion (adrenarche) and activation of the hypothalamic-pituitary-gonadal axis (gonadarche). One factor thought to contribute to the adrenarche in man is increased adrenal 17-hydroxylase (CYP17) activity. In the rat, there is evidence for adrenal involvement in the initiation of puberty, but the adrenal glands of this species are generally thought to express CYP17 only very poorly at best. To further examine the nature of postnatal adrenal development in rat, plasma samples and adrenal tissues were taken from animals aged 2-90 days, circulating adrenal steroids assayed, and adrenal zones assessed quantitatively. A relative increase in zona reticularis, and peaks of circulating cortisol, androstenedione, and 17-OH-progesterone were observed around postnatal days 16-20, clearly before the development of the gonads, which begins at 30-35 days. Quantitative reverse transcriptase PCR confirmed a peak in mRNA coding for CYP17 in adrenal tissue from rats of similar age. The results suggest that the rat adrenal has the capacity to secrete steroids arising from 17-hydroxylation, and that this may contribute to a process similar to human adrenarche.

  12. Rat on Mars

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This image taken on Mars by the panoramic camera on the Mars Exploration Rover Opportunity shows the rover's rock abrasion tool, also known as 'rat' (circular device in center), located on its instrument deployment device, or 'arm.' The image was acquired on the ninth martian day or sol of the rover's mission.

  13. Behavior modulation of rats to a robotic rat in multi-rat interaction.

    PubMed

    Shi, Qing; Ishii, Hiroyuki; Tanaka, Katsuaki; Sugahara, Yusuke; Takanishi, Atsuo; Okabayashi, Satoshi; Huang, Qiang; Fukuda, Toshio

    2015-10-01

    In this paper, we study the behavioral response of rats to a robotic rat during multi-rat interaction. Experiments are conducted in an open-field where a robotic rat called WR-5 is put together with three laboratory rats. WR-5 is following one rat (target), while avoiding the other two rats (outside observers) during interaction. The behavioral characteristics of each target rat is evaluated by scoring its locomotor activity and frequencies of performing rearing, body grooming and mounting actions. Additionally, the frequency of being mounted by other rats is also measured. Experimental results show that the target becomes more active after interaction. The rat species, with more active behavioral characteristics, is more susceptible to being adjusted by the robot. The increased time spent by the outside observers in the vicinity of the robot indicates that a biomimetic robot has the promise for modulating rat behavior even without direct interaction. Thus, this study provide a novel approach to shaping the sociality of animals living in groups. PMID:26414400

  14. Behavior modulation of rats to a robotic rat in multi-rat interaction.

    PubMed

    Shi, Qing; Ishii, Hiroyuki; Tanaka, Katsuaki; Sugahara, Yusuke; Takanishi, Atsuo; Okabayashi, Satoshi; Huang, Qiang; Fukuda, Toshio

    2015-10-01

    In this paper, we study the behavioral response of rats to a robotic rat during multi-rat interaction. Experiments are conducted in an open-field where a robotic rat called WR-5 is put together with three laboratory rats. WR-5 is following one rat (target), while avoiding the other two rats (outside observers) during interaction. The behavioral characteristics of each target rat is evaluated by scoring its locomotor activity and frequencies of performing rearing, body grooming and mounting actions. Additionally, the frequency of being mounted by other rats is also measured. Experimental results show that the target becomes more active after interaction. The rat species, with more active behavioral characteristics, is more susceptible to being adjusted by the robot. The increased time spent by the outside observers in the vicinity of the robot indicates that a biomimetic robot has the promise for modulating rat behavior even without direct interaction. Thus, this study provide a novel approach to shaping the sociality of animals living in groups.

  15. Rat retinal transcriptome

    PubMed Central

    Kozhevnikova, Oyuna S.; Korbolina, Elena E.; Ershov, Nikita I.; Kolosova, Natalia G.

    2013-01-01

    Pathogenesis of age-related macular degeneration (AMD), the leading cause of vision loss in the elderly, remains poorly understood due to the paucity of animal models that fully replicate the human disease. Recently, we showed that senescence-accelerated OXYS rats develop a retinopathy similar to human AMD. To identify alterations in response to normal aging and progression of AMD-like retinopathy, we compared gene expression profiles of retina from 3- and 18-mo-old OXYS and control Wistar rats by means of high-throughput RNA sequencing (RNA-Seq). We identified 160 and 146 age-regulated genes in Wistar and OXYS retinas, respectively. The majority of them are related to the immune system and extracellular matrix turnover. Only 24 age-regulated genes were common for the two strains, suggestive of different rates and mechanisms of aging. Over 600 genes showed significant differences in expression between the two strains. These genes are involved in disease-associated pathways such as immune response, inflammation, apoptosis, Ca2+ homeostasis and oxidative stress. The altered expression for selected genes was confirmed by qRT-PCR analysis. To our knowledge, this study represents the first analysis of retinal transcriptome from young and old rats with biologic replicates generated by RNA-Seq technology. We can conclude that the development of AMD-like retinopathy in OXYS rats is associated with an imbalance in immune and inflammatory responses. Aging alters the expression profile of numerous genes in the retina, and the genetic background of OXYS rats has a profound impact on the development of AMD-like retinopathy. PMID:23656783

  16. Erythrocytosis in Spontaneously Hypertensive Rats

    PubMed Central

    Sen, Subha; Hoffman, George C.; Stowe, Nicholas T.; Smeby, Robert R.; Bumpus, F. Merlin

    1972-01-01

    During the study of an inbred strain of Wistar rats which spontaneously develop hypertension when they reach a weight of approximately 150 g, it was found that these animals also develop an erythrocytosis. A significant increase in red cell count was observed in spontaneously hypertensive (SH) rats (8-11 × 106 RBC/mm3) when compared with normotensive rats (6-7 × 106 RBC/mm3) of the same strain. This increase in red cell count paralleled the increase in body weight and the rise in blood pressure. Since the plasma volume, as measured with labeled albumin was normal, there was an absolute increase in red cells. The hematocrit and hemoglobin content of the blood measured in SH rats were only slightly greater than those found in normotensive rats. However, the mean cell volume (MCV) of the red cells in the SH rats was 45-47 μ3 as compared with 51-53 μ3 in normotensive rats. A fourfold increase in 24 hr 59Fe incorporation into the red cells was found in the SH rats when compared with normotensive controls. The bone marrow of the SH rats showed erythroid hyperplasia. When the SH rats were treated with α-methyldopa (Aldomet 200 mg/kg daily, i.p.) the red cell count fell in parallel with the drop in blood pressure. No change in red cell count or blood pressure was observed in normotensive rats treated in the same manner. The erythropoietin titer was high in SH rats, and was undetectable in normotensive rats. These observations suggest a direct relationship between the hypertension and the erythrocytosis mediated by erythropoietin; both are genetically controlled. PMID:5011107

  17. Gravitational Biology: The Rat Model

    NASA Technical Reports Server (NTRS)

    1997-01-01

    In this session, Session JP3, the discussion focuses on the following topics: Morphology of brain, pituitary and thyroid in the rats exposed to altered gravity; Biochemical Properties of B Adrenoceptors After Spaceflight (LMS-STS78) or Hindlimb Suspension in Rats; Influence of Hypergravity on the Development of Monoaminergic Systems in the Rat Spinal Cord; A Vestibular Evoked Potentials (VsEPs) Study of the Function of the Otolith Organs in Different Head Orientations with respect to Earth Gravity Vector in the Rat; Quantitative Observations on the Structure of Selected Proprioceptive Components in Adult Rats that Underwent About Half of their Fetal Development in Space; Effects of a Nine-Day Shuttle Mission on the Development of the Neonatal Rat Nervous System, A Behavioral Study; Muscle Atrophy Associated to Microgravity in Rat, Basic Data For Countermeasures; Simulated Weightlessness by Unloading in the Rat, Results of a Time Course Study of Biochemical Events Occurring During Unloading and Lack of Effect of a rhBNP-2 Treatment on Bone Formation and Bone Mineral Content in Unloading Rats; and Cytological Mechanism of the Osteogenesis Under Microgravity Conditions.

  18. URINARY CALCULI IN GERMFREE RATS

    PubMed Central

    Gustafsson, Bengt E.; Norman, Arne

    1962-01-01

    In a colony of germfree rats 50 per cent of the males had urinary calculi composed of calcium citrate and calcium oxalate. Genetically closely related conventional animals on the same sterilized diet did not present a single case of stone formation. The tendency to calculus formation disappeared when germfree animals were contaminated with the intestinal flora from conventional rats. The calculus formation can readily be explained by the high calcium, high citrate, and high pH of the urine. This pattern was changed to that of conventional rats when the germfree rats were infected with intestinal microorganisms. PMID:13903130

  19. Laughing rats are optimistic.

    PubMed

    Rygula, Rafal; Pluta, Helena; Popik, Piotr

    2012-01-01

    Emotions can bias human decisions- for example depressed or anxious people tend to make pessimistic judgements while those in positive affective states are often more optimistic. Several studies have reported that affect contingent judgement biases can also be produced in animals. The animals, however, cannot self-report; therefore, the valence of their emotions, to date, could only be assumed. Here we present the results of an experiment where the affect-contingent judgement bias has been produced by objectively measured positive emotions. We trained rats in operant Skinner boxes to press one lever in response to one tone to receive a food reward and to press another lever in response to a different tone to avoid punishment by electric foot shock. After attaining a stable level of discrimination performance, the animals were subjected to either handling or playful, experimenter-administered manual stimulation - tickling. This procedure has been confirmed to induce a positive affective state in rats, and the 50-kHz ultrasonic vocalisations (rat laughter) emitted by animals in response to tickling have been postulated to index positive emotions akin to human joy. During the tickling and handling sessions, the numbers of emitted high-frequency 50-kHz calls were scored. Immediately after tickling or handling, the animals were tested for their responses to a tone of intermediate frequency, and the pattern of their responses to this ambiguous cue was taken as an indicator of the animals' optimism. Our findings indicate that tickling induced positive emotions which are directly indexed in rats by laughter, can make animals more optimistic. We demonstrate for the first time a link between the directly measured positive affective state and decision making under uncertainty in an animal model. We also introduce innovative tandem-approach for studying emotional-cognitive interplay in animals, which may be of great value for understanding the emotional-cognitive changes

  20. Prospective cognition in rats

    PubMed Central

    Crystal, Jonathon D.

    2012-01-01

    Efforts to develop animal models of memory are critical for understanding the neural substrate of memory. Memory is essential for daily life and enables information to be stored and retrieved after seconds to years. The ability to remember episodes from the past is thought to be related to the ability to plan for the future. Here we focus on a particular aspect of prospective cognition, namely the ability to remember to take action when a future scenario occurs. This review focuses on a recently developed method to evaluate prospective memory in the rat. Available evidence suggests that rats remember to take action in the future, but little is known about the temporal specificity of such memories or about the flexibility and limitations of prospective memories. Recent studies that suggest that rats remember a specific past episode are reviewed to underscore potential approaches that may be used to explore the range and limits of prospective cognition. The review highlights some directions to explore, including the temporal specificity of prospective cognition, the range of flexibility or creativity within prospective cognition, and the constraints imposed by multiple motivational systems. PMID:23180886

  1. Effect of Leaf Extracts of Aloe arborescens Mill subsp. natalensis Berger on Growth of Trichophyton mentagrophytes

    PubMed Central

    Fujita, Keisuke; Yamada, Yasuo; Azuma, Keizou; Hirozawa, Susumu

    1978-01-01

    The antifungal activity of a lyophilized powder containing aloe leaf homogenate (whole-leaf powder) against Trichophyton mentagrophytes was investigated. The minimal inhibitory concentration was 25 mg/ml by the agar dilution method, using Sabouraud glucose agar medium. At subinhibitory concentrations, the powder exerted its main effect on colony growth by prolongation of the lag phase and inhibition of growth rate. Homogenates of fresh whole leaf were filtered through Whatman GF/A paper, and the filtrate was dialyzed and concentrated by molecular filtration using an Amicon hollow-fiber dialyzer concentrator DC-2, and a powder containing components with molecular weights higher than 10,000 (high-molecular-weight component powder) was prepared by lyophilization. The minimal inhibitory concentrations against three strains of T. mentagrophytes were all 10 mg/ml. The inhibitory activity was fungicidal and was lost by heating at 100°C for 30 min. Both the whole-leaf powder and the high-molecular-weight component powder induced various morphological abnormalities in spores and hyphae by the inhibition of spore germination and development of hyphae. Images PMID:686703

  2. [Cereal grain preference of rats].

    PubMed

    Wang, P Y

    1990-07-01

    Cereal grains are usually used as the main material for preparing rodenticide baits. However, the preferences for different grains varies according to species and habitats of rats, and locations. A formula accepted at one location may not be suitable in other places, where rats are accustomed to different types of food. It is therefore important to understand the feeding habits of local rat species before implementing a control program. Seven kinds of grains, including hulled rice, corn, barley, wheat, sorghum, pranuts, and sweet potatoes were tested to study the preferences of rats in the laboratory. The results revealed that Bandicota nemorivaga, Rattus losea and R. norvegicus prefer hulled rice; Apodemus agrarius and Mus musculus prefer peanuts, and R. rattus prefers corn. The influence of quality and nutrient contents of baits on the consumption of the rats is also discussed. PMID:2402029

  3. [Cereal grain preference of rats].

    PubMed

    Wang, P Y

    1990-07-01

    Cereal grains are usually used as the main material for preparing rodenticide baits. However, the preferences for different grains varies according to species and habitats of rats, and locations. A formula accepted at one location may not be suitable in other places, where rats are accustomed to different types of food. It is therefore important to understand the feeding habits of local rat species before implementing a control program. Seven kinds of grains, including hulled rice, corn, barley, wheat, sorghum, pranuts, and sweet potatoes were tested to study the preferences of rats in the laboratory. The results revealed that Bandicota nemorivaga, Rattus losea and R. norvegicus prefer hulled rice; Apodemus agrarius and Mus musculus prefer peanuts, and R. rattus prefers corn. The influence of quality and nutrient contents of baits on the consumption of the rats is also discussed.

  4. Nephrotoxicity of ifosfamide in rats.

    PubMed

    Springate, J E; Van Liew, J B

    1995-01-01

    Renal proximal tubule cell injury is an important side effect of the chemotherapeutic agent ifosfamide in humans. We investigated the effect of this medication on kidney function in rats. Animals received either 40 or 80 mg kg(-1) ifosfamide intraperitoneally daily for 3 days every 3 weeks for a total of four treatment courses. Ifosfamide-treated rats had significantly lower body weight and hematocrit than sterile water-treated control rats. Animals receiving 40 mg kg(-1) ifosfamide developed isolated phosphaturia after their fourth and final treatment course. Rats receiving 80 mg kg(-1) ifosfamide had low-grade glucosuria, phosphaturia and proteinuria throughout the study. Urine flow rate, creatinine clearance, urinary sodium and potassium excretion and kidney glutathione and malondialdehyde content were not affected by ifosfamide at either dose. These findings indicate that ifosfamide produces abnormalities in rat renal function resembling subclinical Fanconi syndrome.

  5. War on Rats, 1972 Progress Report.

    ERIC Educational Resources Information Center

    District of Columbia Dept. of Environmental Services, Washington, DC.

    The City of Washington, D.C., with federal funding, declared war on one of the city's most pressing problems--rats. The War on Rats Program, in conjunction with Operation Clean Sweep, made a city-wide survey of rat infestations and recorded the areas of heavy rat infestation. After the problem areas had been identified, community organizations…

  6. Radiation induced heart disease in hypertensive rats

    SciTech Connect

    Lauk, S.; Trott, K.R.

    1988-01-01

    Spontaneously hypertensive Wistar rats were given single doses of X rays to their heart. Irradiation decreased the blood pressure before any myocardial radiation damage was apparent. Male rats, which were more hypertensive than female rats, had a shorter survival time after local heart irradiation than female rats. Antihypertensive treatment with hydralazine did not increase the survival time. It is considered that myocardial hypertrophy is the cause of the increased susceptibility of spontaneously hypertensive rats to local heart irradiation.

  7. Generation of Hprt-disrupted rat through mouse←rat ES chimeras

    PubMed Central

    Isotani, Ayako; Yamagata, Kazuo; Okabe, Masaru; Ikawa, Masahito

    2016-01-01

    We established rat embryonic stem (ES) cell lines from a double transgenic rat line which harbours CAG-GFP for ubiquitous expression of GFP in somatic cells and Acr3-EGFP for expression in sperm (green body and green sperm: GBGS rat). By injecting the GBGS rat ES cells into mouse blastocysts and transplanting them into pseudopregnant mice, rat spermatozoa were produced in mouse←rat ES chimeras. Rat spermatozoa from the chimeric testis were able to fertilize eggs by testicular sperm extraction combined with intracytoplasmic sperm injection (TESE-ICSI). In the present paper, we disrupted rat hypoxanthine-guanine phosphoribosyl transferase (Hprt) gene in ES cells and produced a Hprt-disrupted rat line using the mouse←rat ES chimera system. The mouse←rat ES chimera system demonstrated the dual advantages of space conservation and a clear indication of germ line transmission in knockout rat production. PMID:27062982

  8. Rat myocardial protein degradation.

    PubMed

    Steer, J H; Hopkins, B E

    1981-07-01

    1. Myocardial protein degradation rates were determined by following tyrosine release from rat isolated left hemi-atria in vitro. 2. After two 20 min preincubations the rate of tyrosine release from hemi-atria was constant for 4 h. 3. Skeletal muscle protein degradation was determined by following tyrosine release from rat isolated hemi-diaphragm (Fulks, Li & Goldberg, 1975). 4. Insulin (10(-7) M) inhibited tyrosine release from hemi-atria and hemi-diaphragm to a similar extent. A 48 h fast increased tyrosine release rate from hemi-diaphragm and decreased tyrosine release rate from hemi-atria. Hemi-diaphragm tyrosine release was inhibited by 15 mmol/l D-glucose but a variety of concentrations of D-glucose (0, 5, 15 mmol/l) had no effect on tyrosine release from hemi-atria. Five times the normal plasma levels of the branched-chain amino acids leucine, isoleucine and valine had no effect on tyrosine release from either hemi-atria or hemi-diaphragm.

  9. Stress-reactive rats (high-avoidance female rats) have a shorter lifespan than stress-nonreactive rats (low-avoidance female rats)

    PubMed Central

    Ohta, Ryo; Kumagai, Fumiaki; Marumo, Hideki; Usumi, Kenji; Saito, Yoshiaki; Kuwagata, Makiko

    2015-01-01

    Although Hatano high-avoidance and low-avoidance rats (HAA and LAA, respectively) have been selectively bred for good versus poor avoidance learning, HAA rats are known to be more reactive to stress than LAA rats. In this study, HAA and LAA female rats were compared during reproductive aging by observing estrous cycles from 8 to 11 months of age. Furthermore, these rats were allowed to live out their natural lifespans, that is, until 24 months of age, in order to compare their survival and to clarify the relationship between reproductive aging and tumor development. At eight months of age, 2 of 35 HAA rats and 20 of 35 LAA rats had abnormal estrous cycles. The median lifespan of the HAA rats (673 days) was shorter than that of the LAA rats (733 days). The incidence of pituitary neoplasia was higher in the HAA rats than in the LAA rats. These results suggest that HAA female rats (i.e., stress-reactive rats) have a shorter lifespan than LAA female rats (i.e., stress-nonreactive rats) and develop pituitary neoplasia, which was one of the causal factors in their accelerated mortality. However, the onset of an age-matched abnormal cycle did not correspond with their lifespan. PMID:27182111

  10. Beta-endorphin in genetically hypoprolactinemic rat: IPL nude rat

    SciTech Connect

    Cohen, H.; Sabbagh, I.; Abou-Samra, A.B.; Bertrand, J.

    1986-01-20

    Beta-endorphin has been reported to regulate not only stress- and suckling-induced but also basal prolactin secretion. In the aim to better evaluate the endogenous beta-endorphin-prolactin interrelation, the authors measured beta-endorphin levels in a new rat strain, genetically hypoprolactinemic and characterized by a total lack of lactation: IPL nude rat. Beta-endorphin was measured using a specific anti-h-..beta.. endorphin in plasma and extracts of anterior and neurointermediate lobes of the pituitary, hypothalamus and brain. Pituitary extracts were also chromatographed on Sephadex G50 column. Results obtained showed that in IPL nude females on diestrus and males, the beta-endorphin contents of the neurointermediate lobe was significantly lower than in normal rats, while the values found in the other organs and plasma were similar. However, elution pattern of the anterior pituitary extracts from male rats showed greater immunoactivity eluting as I/sup 125/ h-beta-endorphin than in normal rat; this was not the case for the female rat. These results are consistent with a differential regulation of beta-endorphin levels of anterior and neurointermediate lobe by catecholamines. Moreover they suggest that PRL secretion was more related to neurointermediate beta-endorphin. 40 references, 2 figures, 4 tables.

  11. Hormonal changes in antiorthostatic rats

    NASA Technical Reports Server (NTRS)

    Popovic, V.; Popovic, P.; Honeycutt, C.

    1982-01-01

    Hypokinesia, especially hypokinesia with negative tilt ('antiorthostatic hypokinesia'), mimics some of the effects of weightlessness. It is shown that cardiac output is increased during early exposure of rats to antiorthostatic hypokinesia. The increase of the stroke volume and of the cardiac output observed in the antiorthostatic hypokinetic rats is probably the consequence of a blood volume shift toward the chest brought forth by head-down positioning of the animals. It is also possible that struggling of the animals to escape from the harness and an increased metabolism contribute to the elevation of cardiac output. In order to study this hypothesis 'stress hormones' were measured in the antiorthostatic rats. Plasma levels of ACTH, corticosterone and prolactin were measured in the arterial blood (0.3 ml) sampled before, during and after hypokinesia from chronic aortic cannulas of the rats.

  12. Autoshaping in micrencephalic rats

    SciTech Connect

    Goldstein, L.H.; Oakley, D.A.

    1989-06-01

    An autoshaping procedure in which the illumination of a lever was predictive of food reinforcement was used to compare learning in rats with micrencephaly induced by irradiation on the 16th day of gestation and in sham-irradiated controls. Both groups showed equivalent levels of lever-directed activity, and the micrencephalic animals differentiated as well as the control animals between the predictive lever and a nonpredictive lever. The micrencephalic animals were able to redistribute their lever-directed activity when the significance of the levers was reversed and did so more readily than the control animals. Results support the claim that association learning survives either traumatic or developmental neocortical damage and have implications for remedial procedures following both head injury and developmental cerebral pathology in humans.

  13. Do infant rats cry?

    PubMed

    Blumberg, M S; Sokoloff, G

    2001-01-01

    In the current revival of interest in the emotional and mental lives of animals, many investigators have focused attention on mammalian infants that emit distress vocalizations when separated from the home environment. Perhaps the most intensively studied distress vocalization is the ultrasonic vocalization of infant rats. Since its discovery, this vocalization has been interpreted both as a communicatory signal for the elicitation of maternal retrieval and as the manifestation of emotional distress. In contrast, the authors examined the cardiovascular causes and consequences of the vocalization, and on the basis of this work, they hypothesized that the vocalization is the acoustic by-product of the abdominal compression reaction (ACR), a maneuver that results in increased venous return to the heart. Therefore, the vocalization may be analogous to a sneeze, serving a physiological function while incidentally producing sound. PMID:11212634

  14. Signal detection in the rat.

    PubMed

    HACK, M H

    1963-02-22

    An auditory detection experiment was performed with rats as subjects, and the data were analyzed with a signal detection model. Rats were run at fixed sound pressure levels, and their responses were partitioned so that operating characteristics could be constructed. Measures of detectability, (d(e))((1/2)), were calculated from the operating characteristics, and show that (d(e))((1/2)) is a function of sound pressure levels, rising as these levels rise.

  15. Senescence-accelerated OXYS rats

    PubMed Central

    Stefanova, Natalia A; Kozhevnikova, Oyuna S; Vitovtov, Anton O; Maksimova, Kseniya Yi; Logvinov, Sergey V; Rudnitskaya, Ekaterina A; Korbolina, Elena E; Muraleva, Natalia A; Kolosova, Nataliya G

    2014-01-01

    Senescence-accelerated OXYS rats are an experimental model of accelerated aging that was established from Wistar stock via selection for susceptibility to cataractogenic effects of a galactose-rich diet and via subsequent inbreeding of highly susceptible rats. Currently, we have the 102nd generation of OXYS rats with spontaneously developing cataract and accelerated senescence syndrome, which means early development of a phenotype similar to human geriatric disorders, including accelerated brain aging. In recent years, our group found strong evidence that OXYS rats are a promising model for studies of the mechanisms of brain aging and neurodegenerative processes similar to those seen in Alzheimer disease (AD). The manifestation of behavioral alterations and learning and memory deficits develop since the fourth week of age, i.e., simultaneously with first signs of neurodegeneration detectable on magnetic resonance imaging and under a light microscope. In addition, impaired long-term potentiation has been demonstrated in OXYS rats by the age of 3 months. With age, neurodegenerative changes in the brain of OXYS rats become amplified. We have shown that this deterioration happens against the background of overproduction of amyloid precursor protein (AβPP), accumulation of β-amyloid (Aβ), and hyperphosphorylation of the tau protein in the hippocampus and cortex. The development of AMD-like retinopathy in OXYS rats is also accompanied by increased accumulation of Aβ in the retina. These published data suggest that the OXYS strain may serve as a spontaneous rat model of AD-like pathology and could help to decipher the pathogenesis of AD. PMID:24552807

  16. EXPERIMENTAL PARACOCCIDIOIDOMYCOSIS IN PREGNANT RATS.

    PubMed

    Loth, Eduardo Alexandre; Cecatto, Vanessa; Biazim, Samia Khalil; Ferreira, José Henrique Fermino; Danielli, Caroline; Genske, Rodrigo Daniel; Gandra, Rinaldo Ferreira; Franco, Marcello Fabiano de

    2015-12-01

    Paracoccidioidomycosis (PCM), caused by the dimorphic fungus Paracoccidioides brasiliensis (Pb), is the most prevalent systemic mycosis in Latin America. There are few reports in the literature about the disease damages during pregnancy and the consequences to the fetuses and breeding. This study evaluated the implications of PCM during pregnancy on offspring and mothers in Wistar rats. Groups of rats were submitted to systemic Pb infection, by intraperitoneal infusion, and mated 30 days after the infection date. Immediately after birth, rats and neonates were sacrificed to obtain organs for standard histological examination, morphometric analysis, fungi recovery by plating (CFU) and dosing of anti-Pb antibodies by ELISA. There were no stillbirths or miscarriages, however, the fetuses from infected pregnant rats had lower body and organ weight but the fertility rate was 100%. The largest number of CFU was recovered from the organ of pregnant rats, the pathological examination revealed more severe infection in the same group, further on the largest number of granulomas and fungal field. It can be concluded that the PCM was more severe in the group of pregnant rats, with implications to the weight of offspring.

  17. EXPERIMENTAL PARACOCCIDIOIDOMYCOSIS IN PREGNANT RATS

    PubMed Central

    LOTH, Eduardo Alexandre; CECATTO, Vanessa; BIAZIM, Samia Khalil; FERREIRA, José Henrique Fermino; DANIELLI, Caroline; GENSKE, Rodrigo Daniel; GANDRA, Rinaldo Ferreira; de FRANCO, Marcello Fabiano

    2015-01-01

    Paracoccidioidomycosis (PCM), caused by the dimorphic fungus Paracoccidioides brasiliensis (Pb), is the most prevalent systemic mycosis in Latin America. There are few reports in the literature about the disease damages during pregnancy and the consequences to the fetuses and breeding. This study evaluated the implications of PCM during pregnancy on offspring and mothers in Wistar rats. Groups of rats were submitted to systemic Pb infection, by intraperitoneal infusion, and mated 30 days after the infection date. Immediately after birth, rats and neonates were sacrificed to obtain organs for standard histological examination, morphometric analysis, fungi recovery by plating (CFU) and dosing of anti-Pb antibodies by ELISA. There were no stillbirths or miscarriages, however, the fetuses from infected pregnant rats had lower body and organ weight but the fertility rate was 100%. The largest number of CFU was recovered from the organ of pregnant rats, the pathological examination revealed more severe infection in the same group, further on the largest number of granulomas and fungal field. It can be concluded that the PCM was more severe in the group of pregnant rats, with implications to the weight of offspring. PMID:27049707

  18. False Context Fear Memory in Rats

    ERIC Educational Resources Information Center

    Bae, Sarah; Holmes, Nathan M.; Westbrook, R. Frederick

    2015-01-01

    Four experiments used rats to study false context fear memories. In Experiment 1, rats were pre-exposed to a distinctive chamber (context A) or to a control environment (context C), shocked after a delay in a second chamber (context B) and tested either in B or A. Rats pre-exposed to A froze just as much as control rats in B but more than control…

  19. Does rat fetal DNA induce preeclampsia in pregnant rats?

    PubMed

    Konečná, B; Borbélyová, V; Celec, P; Vlková, B

    2015-02-01

    Cell-free fetal DNA in maternal circulation is higher during preeclampsia. It is unclear whether it is the cause or the consequence of the disease. The aim of this study was to prove whether injected rat fetal DNA induces preeclampsia-like symptoms in pregnant Wistar rats. They received daily i.p. injections of water or rat fetal DNA (400 μg) from gestation day 14 to 18. Blood pressure, proteinuria, placental and fetal weight were measured at gestation day 19. Plasma DNase activity, proteinuria and creatinine clearance were assessed. There was no significant difference in any of the measured parameters. The results of this study do not confirm the hypothesis that fetal DNA might induce preeclampsia. This is in contrast to others using human fetal DNA in mice. Further studies should be focused on the effects of fetal DNA from the same species protected from DNase activity.

  20. Prospective memory in the rat

    PubMed Central

    Wilson, A. George; Crystal, Jonathon D.

    2011-01-01

    The content of prospective memory is comprised of representations of an action to perform in the future. When people form prospective memories, they temporarily put the memory representation in an inactive state while engaging in other activities, and then activate the representation in the future. Ultimately, successful activation of the memory representation yields an action at an appropriate, but temporally distant, time. A hallmark of prospective memory is that activation of the memory representation has a deleterious effect on current ongoing activity. Recent evidence suggests that scrub jays and non-human primates, but not other species, are capable of future planning. We hypothesized that prospective memory produces a selective deficit in performance at the time when rats access a memory representation but not when the memory representation is inactive. Rats were trained in a temporal bisection task (90 min/day). Immediately after the bisection task, half of the rats received an 8-g meal (meal group) and the other rats received no additional food (no-meal group). Sensitivity to time in the bisection task was reduced as the 90-min interval elapsed for the meal group but not for the no-meal group. This time-based prospective-memory effect was not based on response competition, an attentional limit, anticipatory contrast, or fatigue. Our results suggest that rats form prospective memories, which produces a negative side effect on ongoing activity. PMID:21922257

  1. Source memory in the rat

    PubMed Central

    Crystal, Jonathon D.; Alford, Wesley T.; Zhou, Wenyi; Hohmann, Andrea G.

    2013-01-01

    Summary Source memory is a representation of the origin (source) of information. When source information is bound together, it makes a memory episodic, allowing us to differentiate one event from another [1, 2]. Here we asked if rats remember the source of encoded information. Rats foraged for distinctive flavors of food that replenished (or failed to replenish) at its recently encountered location according to a source-information rule. To predict replenishment, rats needed to remember where they had encountered a preferred food type (chocolate) with self-generated (walking along a runway encountering chocolate) or experimenter-generated (placement of the rat at the chocolate site by an experimenter) cues. Three lines of evidence implicate the presence of source memory. First, rats selectively adjusted revisits to the chocolate location based on source information, under conditions in which familiarity of events could not produce successful performance. Second, source memory was dissociated from location memory by different decay rates. Third, temporary inactivation of the CA3 region of the hippocampus with lidocaine selectively eliminated source memory, suggesting that source memory is dependent upon an intact hippocampus. Development of an animal model of source memory may be valuable to probe the biological underpinnings of memory disorders marked by impairments in source memory. PMID:23394830

  2. Tuberculosis Detection by Giant African Pouched Rats

    ERIC Educational Resources Information Center

    Poling, Alan; Weetjens, Bart; Cox, Christophe; Beyene, Negussie; Durgin, Amy; Mahoney, Amanda

    2011-01-01

    In recent years, operant discrimination training procedures have been used to teach giant African pouched rats to detect tuberculosis (TB) in human sputum samples. This article summarizes how the rats are trained and used operationally, as well as their performance in studies published to date. Available data suggest that pouched rats, which can…

  3. Using rats for vision research.

    PubMed

    Reinagel, P

    2015-06-18

    A wide variety of species are used for the study of visual neuroscience. This is beneficial because fundamental mechanisms and theoretical principles of vision are likely to be highly conserved, while different species exhibit different visual capacities and present different technical advantages for experiments. Eight years ago my laboratory adopted the hooded rat as our primary preparation for vision research. To some this may be surprising, as nocturnal rodents have often been presumed to have poor vision and weak visual behavior. This commentary will provide my personal perspective on how I came to work with rats; discuss an example research project for which rats have been advantageous; and comment on the opportunities and challenges of the preparation.

  4. Rats are sensitive to ambiguity.

    PubMed

    Fast, Cynthia D; Blaisdell, Aaron P

    2011-12-01

    In the present study, we investigated response decisions made under conditions of incomplete information in rats. In Experiment 1, rats were trained on either a positive patterning (PP; A-, B-, AB+) or a negative patterning (NP; A+, B+, AB-) instrumental lever-press discrimination. Subjects that had learned an NP discrimination responded less to Cue A when Cue B was covered at test. The cover did not, however, affect test responses to Cue A in the PP condition. In Experiment 2, rats received concurrent training on both PP and NP discriminations. After concurrent training, responses to Cue A were different with B covered versus uncovered for both NP and PP discriminations. We discuss possible accounts for why exposure to a nonlinearly soluble discrimination (NP) may have affected sensitivity to cue ambiguity produced by the cover. These results have interesting implications for representational processes engaged in problem solving.

  5. Identification of Arabidopsis rat Mutants

    PubMed Central

    Zhu, Yanmin; Nam, Jaesung; Humara, Jaime M.; Mysore, Kirankumar S.; Lee, Lan-Ying; Cao, Hongbin; Valentine, Lisa; Li, Jingling; Kaiser, Anthony D.; Kopecky, Andrea L.; Hwang, Hau-Hsuan; Bhattacharjee, Saikat; Rao, Praveen K.; Tzfira, Tzvi; Rajagopal, Jyothi; Yi, HoChul; Veena; Yadav, Badam S.; Crane, Yan M.; Lin, Kui; Larcher, Yves; Gelvin, Matthew J.K.; Knue, Marnie; Ramos, Cynthia; Zhao, Xiaowen; Davis, Susan J.; Kim, Sang-Ic; Ranjith-Kumar, C.T.; Choi, Yoo-Jin; Hallan, Vipin K.; Chattopadhyay, Sudip; Sui, Xiangzhen; Ziemienowicz, Alicja; Matthysse, Ann G.; Citovsky, Vitaly; Hohn, Barbara; Gelvin, Stanton B.

    2003-01-01

    Limited knowledge currently exists regarding the roles of plant genes and proteins in the Agrobacterium tumefaciens-mediated transformation process. To understand the host contribution to transformation, we carried out root-based transformation assays to identify Arabidopsis mutants that are resistant to Agrobacterium transformation (rat mutants). To date, we have identified 126 rat mutants by screening libraries of T-DNA insertion mutants and by using various “reverse genetic” approaches. These mutants disrupt expression of genes of numerous categories, including chromatin structural and remodeling genes, and genes encoding proteins implicated in nuclear targeting, cell wall structure and metabolism, cytoskeleton structure and function, and signal transduction. Here, we present an update on the identification and characterization of these rat mutants. PMID:12805582

  6. Hematopoiesis in antiorthostatic, hypokinesic rats

    NASA Technical Reports Server (NTRS)

    Dunn, C. D. R.; Johnson, P. C.; Lange, R. D.

    1983-01-01

    Rats exposed to antiorthostatic, hypokinesia showed the following effects which are comparable to those seen in man during or after space flight: weight loss, reduced food and water consumption, transient increases in peripheral hematocrit and RBC count, decreasing MCV and reduced reticulocyte count. In addition, the hemoglobin P50 was shifted to the right. A significant shortening of RBC t1/2 was only seen after suspension. Changes in leukocyte and platelet numbers in suspended rats were also comparable to those in man during space flight, but leukocyte PHA sensitivity in rats showed no consistent alteration. The results demonstrate that this model reproduces many of the hematological effects of space flight and has potential as a tool in understanding the hematopoietic response to zero gravity.

  7. Teratology studies in the rat.

    PubMed

    Leroy, Mariline; Allais, Linda

    2013-01-01

    The rat is the rodent species of choice for the regulatory safety testing of xenobiotics, such as medicinal products, food additives, and other chemicals. Many decades of experience and extensive data have accumulated for both general and developmental toxicology investigations in this species. The high fertility and large litter size of the rat are advantages for teratogenicity testing. The study designs are well defined in the regulatory guidelines and are relatively standardized between testing laboratories across the world. Teratology studies address maternal- and embryo-toxicity following exposure during the period of organogenesis. This chapter describes the design and conduct of a teratology study in the rat in compliance with the regulatory guidelines. The procedures for the handling and housing of the pregnant animals, the caesarean examinations and the sampling of fetuses for morphological examinations are described. The utility and design of preliminary studies and the inclusion of satellite animals in the main study for toxicokinetic sampling are discussed.

  8. Swimming-based pica in rats.

    PubMed

    Nakajima, Sadahiko

    2016-09-01

    We have recently demonstrated that voluntary or forced running in activity wheels yields pica behavior (kaolin clay intake) in rats (Nakajima, 2016; Nakajima and Katayama, 2014). The present study provides experimental evidence that a single 40-min session of swimming in water also generates pica in rats, while showering rats with water does not produce such behavior. Because kaolin intake has been regarded as a measure of nausea in rats, this finding suggests that swimming activity, as well as voluntary or forced running, induces nausea in rats. PMID:27370361

  9. Protective Vaccination against Papillomavirus-Induced Skin Tumors under Immunocompetent and Immunosuppressive Conditions: A Preclinical Study Using a Natural Outbred Animal Model

    PubMed Central

    Vinzón, Sabrina E.; Braspenning-Wesch, Ilona; Müller, Martin; Geissler, Edward K.; Nindl, Ingo; Gröne, Hermann-Josef

    2014-01-01

    Certain cutaneous human papillomaviruses (HPVs), which are ubiquitous and acquired early during childhood, can cause a variety of skin tumors and are likely involved in the development of non-melanoma skin cancer, especially in immunosuppressed patients. Hence, the burden of these clinical manifestations demands for a prophylactic approach. To evaluate whether protective efficacy of a vaccine is potentially translatable to patients, we used the rodent Mastomys coucha that is naturally infected with Mastomys natalensis papillomavirus (MnPV). This skin type papillomavirus induces not only benign skin tumours, such as papillomas and keratoacanthomas, but also squamous cell carcinomas, thereby allowing a straightforward read-out for successful vaccination in a small immunocompetent laboratory animal. Here, we examined the efficacy of a virus-like particle (VLP)-based vaccine on either previously or newly established infections. VLPs raise a strong and long-lasting neutralizing antibody response that confers protection even under systemic long-term cyclosporine A treatment. Remarkably, the vaccine completely prevents the appearance of benign as well as malignant skin tumors. Protection involves the maintenance of a low viral load in the skin by an antibody-dependent prevention of virus spread. Our results provide first evidence that VLPs elicit an effective immune response in the skin under immunocompetent and immunosuppressed conditions in an outbred animal model, irrespective of the infection status at the time of vaccination. These findings provide the basis for the clinical development of potent vaccination strategies against cutaneous HPV infections and HPV-induced tumors, especially in patients awaiting organ transplantation. PMID:24586150

  10. Susceptibility of laboratory rats against genotypes 1, 3, 4, and rat hepatitis E viruses.

    PubMed

    Li, Tian-Cheng; Yoshizaki, Sayaka; Ami, Yasushi; Suzaki, Yuriko; Yasuda, Shumpei P; Yoshimatsu, Kumiko; Arikawa, Jiro; Takeda, Naokazu; Wakita, Takaji

    2013-04-12

    To determine whether or not rats are susceptible to hepatitis E virus (HEV) infection, each of group containing three laboratory rats (Wistar) were experimentally inoculated with genotypes 1, 3, 4 and rat HEV by intravenous injection. Serum and stool samples were collected and used to detect HEV RNA and anti-HEV antibodies by RT-PCR and ELISA, respectively. The virus infection was monitored up to 3 months after inoculation. None of the serum or stool samples collected from the rats inoculated with G1, G3, or G4 HEV indicated positive sign for virus replication. Although no alteration was observed in ALT level, rat HEV RNA was detected in stools from both of the rats inoculated with rat HEV, and both rats were positive for anti-rat HEV IgG and IgM from 3 weeks after inoculation. These results demonstrated that rats are susceptible to rat HEV but not to G1, G3, and G4 HEV. We also confirm that the nude rats were useful for obtaining a large amount of rat HEV and that the rat HEV was transmitted by the fecal-oral route.

  11. Slc:Wistar outbred rats show close genetic similarity with F344 inbred rats.

    PubMed

    Nakanishi, Satoshi; Serikawa, Tadao; Kuramoto, Takashi

    2015-01-01

    Although Slc:Wistar rats are used widely in biomedical research as outbred rats, close similarities in growth curves, survival rates, and immunological and biochemical phenotypes have been reported between Slc:Wistar and F344 inbred rats. We reported previously that nine genetic variations that were fixed in Slc:Wistar rats had identical genotypes in F344 rats. Here, we examined the genetic characteristics of Slc:Wistar rats using 27 simple-sequence length polymorphism (SSLP) markers and compared them with other Wistar stocks available in Japan and with some F344 strains. Among 27 SSLP loci, 23 (85%) were fixed in the Slc:Wistar rats, which was the highest among the other Wistar stocks. The 23 fixed loci shared identical genotypes with corresponding loci in F344 rats. Further, the predominant allele types in the unfixed loci had allele frequencies as high as 80%, and these alleles were identical in the F344 rats. When the nine genetic variations reported previously are added, a total of 32 (89%) out of the 36 loci examined were fixed and identical in the Slc:Wistar and F344 rat genomes. These findings indicate the low genetic variation in Slc:Wistar rats and the high genetic similarity between the Slc:Wistar and F344 inbred rats. This study demonstrates the importance of characterizing outbred rats and the need to pay ample attention to the genetic characteristics the Slc:Wistar rats for their proper use.

  12. Struvite Urolithiasis in Long-Evans Rats.

    PubMed

    Pang, Jassia; Borjeson, Tiffany M; Parry, Nicola M A; Fox, James G

    2015-12-01

    Struvite urinary calculi, which are composed of magnesium, ammonium, and phosphate, can cause complications including sepsis and renal failure. Struvite calculi were identified within the urinary bladder and renal pelvis of 2 Long-Evans rats that died within days after arrival from a commercial vendor. The remaining rats in the shipment were screened by physical examination, radiography, and ultrasonography, revealing an additional 2 animals that were clinically affected. These rats were euthanized, necropsied, and yielded similar findings to those from the first 2 rats. In addition, urine samples had an alkaline pH and contained numerous bacteria (predominantly Proteus mirabilis), leukocytes, and crystals. All calculi were composed completely of struvite. Another 7 rats in the shipment had alkaline urine with the presence of blood cells; 6 of these rats also had abundant struvite crystals, and P. mirabilis was cultured from the urine of 3 rats. Further investigation by the vendor identified 2 of 100 rats with struvite calculi from the same colony. Although no specific cause could be implicated, the fact that all the affected rats came from the same breeding area suggests a genetic or environmental triggering event; a contribution due to diet cannot be ruled out. Our findings suggest that the affected rats had metabolic disturbances coupled with bacterial infection that predisposed them to develop struvite calculi. During sudden increases of struvite urinary calculi cases in rats, urine cultures followed by appropriate surgical intervention and antibiotic therapy is warranted. Additional factors, including diet, merit attention as well. PMID:26678365

  13. Struvite Urolithiasis in Long–Evans Rats

    PubMed Central

    Pang, Jassia; Borjeson, Tiffany M; Parry, Nicola MA; Fox, James G

    2015-01-01

    Struvite urinary calculi, which are composed of magnesium, ammonium, and phosphate, can cause complications including sepsis and renal failure. Struvite calculi were identified within the urinary bladder and renal pelvis of 2 Long-Evans rats that died within days after arrival from a commercial vendor. The remaining rats in the shipment were screened by physical examination, radiography, and ultrasonography, revealing an additional 2 animals that were clinically affected. These rats were euthanized, necropsied, and yielded similar findings to those from the first 2 rats. In addition, urine samples had an alkaline pH and contained numerous bacteria (predominantly Proteus mirabilis), leukocytes, and crystals. All calculi were composed completely of struvite. Another 7 rats in the shipment had alkaline urine with the presence of blood cells; 6 of these rats also had abundant struvite crystals, and P. mirabilis was cultured from the urine of 3 rats. Further investigation by the vendor identified 2 of 100 rats with struvite calculi from the same colony. Although no specific cause could be implicated, the fact that all the affected rats came from the same breeding area suggests a genetic or environmental triggering event; a contribution due to diet cannot be ruled out. Our findings suggest that the affected rats had metabolic disturbances coupled with bacterial infection that predisposed them to develop struvite calculi. During sudden increases of struvite urinary calculi cases in rats, urine cultures followed by appropriate surgical intervention and antibiotic therapy is warranted. Additional factors, including diet, merit attention as well. PMID:26678365

  14. Whiskers aid anemotaxis in rats.

    PubMed

    Yu, Yan S W; Graff, Matthew M; Bresee, Chris S; Man, Yan B; Hartmann, Mitra J Z

    2016-08-01

    Observation of terrestrial mammals suggests that they can follow the wind (anemotaxis), but the sensory cues underlying this ability have not been studied. We identify a significant contribution to anemotaxis mediated by whiskers (vibrissae), a modality previously studied only in the context of direct tactile contact. Five rats trained on a five-alternative forced-choice airflow localization task exhibited significant performance decrements after vibrissal removal. In contrast, vibrissal removal did not disrupt the performance of control animals trained to localize a light source. The performance decrement of individual rats was related to their airspeed threshold for successful localization: animals that found the task more challenging relied more on the vibrissae for localization cues. Following vibrissal removal, the rats deviated more from the straight-line path to the air source, choosing sources farther from the correct location. Our results indicate that rats can perform anemotaxis and that whiskers greatly facilitate this ability. Because air currents carry information about both odor content and location, these findings are discussed in terms of the adaptive significance of the interaction between sniffing and whisking in rodents. PMID:27574705

  15. Isolating Lysosomes from Rat Liver.

    PubMed

    Pryor, Paul R

    2016-04-01

    This protocol describes the generation of a fraction enriched in lysosomes from rat liver. The lysosomes are rapidly isolated using density-gradient centrifugation with gradient media that retain the osmolarity of the lysosomes such that they are functional and can be used in in vitro assays.

  16. Whiskers aid anemotaxis in rats

    PubMed Central

    Yu, Yan S. W.; Graff, Matthew M.; Bresee, Chris S.; Man, Yan B.; Hartmann, Mitra J. Z.

    2016-01-01

    Observation of terrestrial mammals suggests that they can follow the wind (anemotaxis), but the sensory cues underlying this ability have not been studied. We identify a significant contribution to anemotaxis mediated by whiskers (vibrissae), a modality previously studied only in the context of direct tactile contact. Five rats trained on a five-alternative forced-choice airflow localization task exhibited significant performance decrements after vibrissal removal. In contrast, vibrissal removal did not disrupt the performance of control animals trained to localize a light source. The performance decrement of individual rats was related to their airspeed threshold for successful localization: animals that found the task more challenging relied more on the vibrissae for localization cues. Following vibrissal removal, the rats deviated more from the straight-line path to the air source, choosing sources farther from the correct location. Our results indicate that rats can perform anemotaxis and that whiskers greatly facilitate this ability. Because air currents carry information about both odor content and location, these findings are discussed in terms of the adaptive significance of the interaction between sniffing and whisking in rodents. PMID:27574705

  17. Whiskers aid anemotaxis in rats.

    PubMed

    Yu, Yan S W; Graff, Matthew M; Bresee, Chris S; Man, Yan B; Hartmann, Mitra J Z

    2016-08-01

    Observation of terrestrial mammals suggests that they can follow the wind (anemotaxis), but the sensory cues underlying this ability have not been studied. We identify a significant contribution to anemotaxis mediated by whiskers (vibrissae), a modality previously studied only in the context of direct tactile contact. Five rats trained on a five-alternative forced-choice airflow localization task exhibited significant performance decrements after vibrissal removal. In contrast, vibrissal removal did not disrupt the performance of control animals trained to localize a light source. The performance decrement of individual rats was related to their airspeed threshold for successful localization: animals that found the task more challenging relied more on the vibrissae for localization cues. Following vibrissal removal, the rats deviated more from the straight-line path to the air source, choosing sources farther from the correct location. Our results indicate that rats can perform anemotaxis and that whiskers greatly facilitate this ability. Because air currents carry information about both odor content and location, these findings are discussed in terms of the adaptive significance of the interaction between sniffing and whisking in rodents.

  18. Transgenic hepatocarcinogenesis in the rat.

    PubMed Central

    Hully, J. R.; Su, Y.; Lohse, J. K.; Griep, A. E.; Sattler, C. A.; Haas, M. J.; Dragan, Y.; Peterson, J.; Neveu, M.; Pitot, H. C.

    1994-01-01

    Although transgenic hepatocarcinogenesis has been accomplished in the mouse with a number of genetic constructs targeting the oncogene to expression primarily in the liver, no example of this process has yet been developed in the rat. Because our understanding of the multistage nature of hepatocarcinogenesis is most advanced in the rat, we have developed a strain of transgenic rats carrying the promoter-enhancer sequences of the mouse albumin gene linked 5' to the simian virus-40 T antigen gene. A line of transgenic rats bearing this transgene has been developed from a single founder female. Five to six copies of the transgene, possibly in tandem, occur within the genome of the transgenic animals, which are maintained by heterozygous matings. Livers of transgenic animals are histologically normal after weaning; at 2 months of age, small foci of vacuolated cells appear in this organ. By 4 months of age, all animals exhibit focal lesions and nodules consisting primarily of small basophilic cells, many of which exhibit considerable cytoplasmic vacuolization. Mating of animals each bearing the transgene results in rats with a demyelinating condition that develops acutely in pregnant females and more chronically in males. Ultrastructural studies of these cells indicate that the vacuoles contain substantial amounts of glycogen, with the cells resembling hepatoblasts. Malignant neoplasms with both a glandular and a hepatoblastoma/hepatocellular carcinoma pattern arise from the nodules. Enzyme and immunohistochemical studies of all lesions reveal many similarities in gene expression to comparable lesions in rats subjected to chemically induced hepatocarcinogenesis, with certain exceptions. The placental form of glutathione-S-transferase is absent from all lesions in the transgenic animal, as is the expression of connexin 32. A significant number of lesions express serum albumin, and many, but not all, exhibit the T antigen. Lesions expressing the T antigen also contain

  19. Kangaroo rat bone compared to white rat bone after short-term disuse and exercise

    USGS Publications Warehouse

    Muths, E.; Reichman, O. J.

    1996-01-01

    Kangaroo rats (Dipodomys ordii) were used to study the effects of confinement on mechanical properties of bone with a long range objective of proposing an alternative to the white rat model for the study of disuse osteoporosis. Kangaroo rats exhibit bipedal locomotion, which subjects their limbs to substantial accelerative forces in addition to the normal stress of weight bearing. We subjected groups of kangaroo rats and white rats (Rattus norvegicus) to one of two confinement treatments or to an exercise regime; animals were exercised at a rate calculated to replicate their (respective) daily exercise patterns. White laboratory rats were used as the comparison because they are currently the accepted model used in the study of disuse osteoporosis. After 6 weeks of treatment, rats were killed and the long bones of their hind limbs were tested mechanically and examined for histomorphometric changes. We found that kangaroo rats held in confinement had less ash content in their hind limbs than exercised kangaroo rats. In general, treated kangaroo rats showed morphometric and mechanical bone deterioration compared to controls and exercised kangaroo rats appeared to have slightly “stronger” bones than confined animals. White rats exhibited no significant differences between treatments. These preliminary results suggest that kangaroo rats may be an effective model in the study of disuse osteoporosis.

  20. Kangaroo rat bone compared to white rat bone after short-term disuse and exercise.

    PubMed

    Muths, E; Reichman, O J

    1996-08-01

    Kangaroo rats (Dipodomys ordii) were used to study the effects of confinement on mechanical properties of bone with a long range objective of proposing an alternative to the white rat model for the study of disuse osteoporosis. Kangaroo rats exhibit bipedal locomotion, which subjects their limbs to substantial accelerative forces in addition to the normal stress of weight bearing. We subjected groups of kangaroo rats and white rats (Rattus norvegicus) to one of two confinement treatments or to an exercise regime; animals were exercised at a rate calculated to replicate their (respective) daily exercise patterns. White laboratory rats were used as the comparison because they are currently the accepted model used in the study of disuse osteoporosis. After 6 weeks of treatment, rats were killed and the long bones of their hind limbs were tested mechanically and examined for histomorphometric changes. We found that kangaroo rats held in confinement had less ash content in their hind limbs than exercised kangaroo rats. In general, treated kangaroo rats showed morphometric and mechanical bone deterioration compared to controls and exercised kangaroo rats appeared to have slightly "stronger" bones than confined animals. White rats exhibited no significant differences between treatments. These preliminary results suggest that kangaroo rats may be an effective model in the study of disuse osteoporosis.

  1. Generalized absence epilepsy and catalepsy in rats.

    PubMed

    Kuznetsova, G D; Petrova, E V; Coenen, A M; Van Luijtelaar, E L

    1996-10-01

    Adult WAG/Rij rats are considered adequate genetic models for human generalized absence epilepsy. Rats of this strain of 8, 12, and 18 weeks old and age-matched control Wistar rats were exposed to sound stimulation. After offset of stimulation, all WAG/Rij rats showed cataleptic or even cataplexic reactions, which could persist for up to 20 min. Age effects could be demonstrated. None of the Wistar rats showed cataleptic reactions. Electroencephalographic studies in WAG/Rij rats of 21 weeks showed that spike-wave discharges were abundantly present in the background electroencephalogram prior to sound stimulation. Age-matched Wistar rats had almost no spike-wave discharges. Spike-wave discharges in WAG/Rij rats disappeared during sound stimulation and were then increased compared to the prestimulation and stimulation periods. The electroencephalogram during the cataleptic state was also characterized by the presence of large amplitude 2 Hz waves, interspersed with spike-wave discharges. The data suggest that the cataleptic state can be elicited in genetically epilepsy-prone rats. The youngest WAG/Rij rats showed no spike-wave discharges during the cataleptic state. In all, the data suggest that epilepsy-prone animals are sensitive for catalepsy at an age at which the EEG signs of generalized absence epilepsy are not yet manifest. PMID:8884948

  2. Advances on genetic rat models of epilepsy.

    PubMed

    Serikawa, Tadao; Mashimo, Tomoji; Kuramoro, Takashi; Voigt, Birger; Ohno, Yukihiro; Sasa, Masashi

    2015-01-01

    Considering the suitability of laboratory rats in epilepsy research, we and other groups have been developing genetic models of epilepsy in this species. After epileptic rats or seizure-susceptible rats were sporadically found in outbred stocks, the epileptic traits were usually genetically-fixed by selective breeding. So far, the absence seizure models GAERS and WAG/Rij, audiogenic seizure models GEPR-3 and GEPR-9, generalized tonic-clonic seizure models IER, NER and WER, and Canavan-disease related epileptic models TRM and SER have been established. Dissection of the genetic bases including causative genes in these epileptic rat models would be a significant step toward understanding epileptogenesis. N-ethyl-N-nitrosourea (ENU) mutagenesis provides a systematic approach which allowed us to develop two novel epileptic rat models: heat-induced seizure susceptible (Hiss) rats with an Scn1a missense mutation and autosomal dominant lateral temporal epilepsy (ADLTE) model rats with an Lgi1 missense mutation. In addition, we have established episodic ataxia type 1 (EA1) model rats with a Kcna1 missense mutation derived from the ENU-induced rat mutant stock, and identified a Cacna1a missense mutation in a N-Methyl-N-nitrosourea (MNU)-induced mutant rat strain GRY, resulting in the discovery of episodic ataxia type 2 (EA2) model rats. Thus, epileptic rat models have been established on the two paths: 'phenotype to gene' and 'gene to phenotype'. In the near future, development of novel epileptic rat models will be extensively promoted by the use of sophisticated genome editing technologies.

  3. Advances on genetic rat models of epilepsy

    PubMed Central

    Serikawa, Tadao; Mashimo, Tomoji; Kuramoto, Takashi; Voigt, Birger; Ohno, Yukihiro; Sasa, Masashi

    2014-01-01

    Considering the suitability of laboratory rats in epilepsy research, we and other groups have been developing genetic models of epilepsy in this species. After epileptic rats or seizure-susceptible rats were sporadically found in outbred stocks, the epileptic traits were usually genetically-fixed by selective breeding. So far, the absence seizure models GAERS and WAG/Rij, audiogenic seizure models GEPR-3 and GEPR-9, generalized tonic-clonic seizure models IER, NER and WER, and Canavan-disease related epileptic models TRM and SER have been established. Dissection of the genetic bases including causative genes in these epileptic rat models would be a significant step toward understanding epileptogenesis. N-ethyl-N-nitrosourea (ENU) mutagenesis provides a systematic approach which allowed us to develop two novel epileptic rat models: heat-induced seizure susceptible (Hiss) rats with an Scn1a missense mutation and autosomal dominant lateral temporal epilepsy (ADLTE) model rats with an Lgi1 missense mutation. In addition, we have established episodic ataxia type 1 (EA1) model rats with a Kcna1 missense mutation derived from the ENU-induced rat mutant stock, and identified a Cacna1a missense mutation in a N-Methyl-N-nitrosourea (MNU)-induced mutant rat strain GRY, resulting in the discovery of episodic ataxia type 2 (EA2) model rats. Thus, epileptic rat models have been established on the two paths: ‘phenotype to gene’ and ‘gene to phenotype’. In the near future, development of novel epileptic rat models will be extensively promoted by the use of sophisticated genome editing technologies. PMID:25312505

  4. Differential Susceptibility of SD and CD Rats to a Novel Rat Theilovirus

    PubMed Central

    Drake, Michael T; Riley, Lela K; Livingston, Robert S

    2008-01-01

    Antibodies to rat theilovirus (RTV) have been detected in rats for many years because of their serologic crossreactivity with strains of Theiler murine encephalomyelitis virus (TMEV) of mice. Little information exists regarding this pathogen, yet it is among the most common viruses detected in serologic surveys of rats used in research. In the study reported here, a novel isolate of RTV, designated RTV1, was cultured from the feces of infected rats. The RTV1 genome contained 8094 nucleotides and had approximately 95% identity with another rat theilovirus, NSG910, and 73% identity with TMEV strains. In addition, the genome size of RTV1 was similar to those of TMEV strains but larger than that reported for NSG910. Oral inoculation of Sprague–Dawley (SD) and CD male rats (n = 10 each group) with RTV1 revealed that SD rats were more susceptible than CD rats to RTV1 infection. At 14 d postinoculation, 100% of SD rats shed virus in the feces, and 70% were positive for RTV serum antibodies. By 56 d postinoculation 30% of SD rats continued to have detectable virus in the feces, and 90% had seroconverted. In contrast, in inoculated CD rats RTV was detected only in the feces at 14 d postinoculation, at which time 40% of CD rats were fecal positive. By 56 d postinoculation only 20% of CD rats had detectable RTV serum antibodies. Our data provide additional sequence information regarding a rat-specific Cardiovirus and indicate that SD rats are more susceptible than CD rats to RTV1 infection. PMID:19004372

  5. Genome Editing in Rats Using TALE Nucleases.

    PubMed

    Tesson, Laurent; Remy, Séverine; Ménoret, Séverine; Usal, Claire; Thinard, Reynald; Savignard, Chloé; De Cian, Anne; Giovannangeli, Carine; Concordet, Jean-Paul; Anegon, Ignacio

    2016-01-01

    The rat is an important animal model to understand gene function and model human diseases. Since recent years, the development of gene-specific nucleases has become important for generating new rat models of human diseases, to analyze the role of genes and to generate human antibodies. Transcription activator-like (TALE) nucleases efficiently create gene-specific knockout rats and lead to the possibility of gene targeting by homology-directed recombination (HDR) and generating knock-in rats. We describe a detailed protocol for generating knockout and knock-in rats via microinjection of TALE nucleases into fertilized eggs. This technology is an efficient, cost- and time-effective method for creating new rat models.

  6. Histomorphometric analysis of rat skeleton following spaceflight

    NASA Technical Reports Server (NTRS)

    Wronski, T. J.; Morey-Holton, E. R.; Doty, S. B.; Maese, A. C.; Walsh, C. C.

    1987-01-01

    Male Sprague-Dawley rats were placed in orbit for 7 days aboard the space shuttle. Bone histomorphometry was performed in the long bones and lumbar vertebrae of flight rats and compared with data derived from ground-based control rats. Trabecular bone mass was not altered during the 1st wk of weightlessness. Strong trends were observed in flight rats for decreased periosteal bone formation in the tibial diaphysis, reduced osteoblast size in the proximal tibia, and decreased osteoblast surface and number in the lumbar vertebra. For the most part, histological indexes of bone resorption were normal in flight rats. The results indicate that 7 days of weightlessness are not of sufficient duration to induce histologically detectable loss of trabecular bone in rats. However, cortical and trabecular bone formation appear to be diminished during the 1st wk of spaceflight.

  7. Isolation of rat adrenocortical mitochondria

    SciTech Connect

    Solinas, Paola; Fujioka, Hisashi; Tandler, Bernard; Hoppel, Charles L.

    2012-10-12

    Highlights: Black-Right-Pointing-Pointer A method for isolation of adrenocortical mitochondria from the adrenal gland of rats is described. Black-Right-Pointing-Pointer The purified isolated mitochondria show excellent morphological integrity. Black-Right-Pointing-Pointer The properties of oxidative phosphorylation are excellent. Black-Right-Pointing-Pointer The method increases the opportunity of direct analysis of adrenal mitochondria from small animals. -- Abstract: This report describes a relatively simple and reliable method for isolating adrenocortical mitochondria from rats in good, reasonably pure yield. These organelles, which heretofore have been unobtainable in isolated form from small laboratory animals, are now readily accessible. A high degree of mitochondrial purity is shown by the electron micrographs, as well as the structural integrity of each mitochondrion. That these organelles have retained their functional integrity is shown by their high respiratory control ratios. In general, the biochemical performance of these adrenal cortical mitochondria closely mirrors that of typical hepatic or cardiac mitochondria.

  8. Automatic Training of Rat Cyborgs for Navigation.

    PubMed

    Yu, Yipeng; Wu, Zhaohui; Xu, Kedi; Gong, Yongyue; Zheng, Nenggan; Zheng, Xiaoxiang; Pan, Gang

    2016-01-01

    A rat cyborg system refers to a biological rat implanted with microelectrodes in its brain, via which the outer electrical stimuli can be delivered into the brain in vivo to control its behaviors. Rat cyborgs have various applications in emergency, such as search and rescue in disasters. Prior to a rat cyborg becoming controllable, a lot of effort is required to train it to adapt to the electrical stimuli. In this paper, we build a vision-based automatic training system for rat cyborgs to replace the time-consuming manual training procedure. A hierarchical framework is proposed to facilitate the colearning between rats and machines. In the framework, the behavioral states of a rat cyborg are visually sensed by a camera, a parameterized state machine is employed to model the training action transitions triggered by rat's behavioral states, and an adaptive adjustment policy is developed to adaptively adjust the stimulation intensity. The experimental results of three rat cyborgs prove the effectiveness of our system. To the best of our knowledge, this study is the first to tackle automatic training of animal cyborgs. PMID:27436999

  9. Toxicity and repellency to rats of actidione

    USGS Publications Warehouse

    Traub, R.; DeWitt, J.B.; Welch, J.F.; Newman, D.

    1950-01-01

    The antibiotic actidione was found to be highly repellent to laboratory rats and to significantly reduce gnawing attacks upon treated paperboards. Rats refused to accept food or water containing this material even under conditions of acute starvation and died of starvation and thirst,rather than accept water containing l.0 mg. of actidione per liter. The compound is highly toxic to .rats with the minimum .lethal dose by oral administration being approximately l.0 mg./Kg body weight. Paperboard treated with the compound resisted gnawing attacks by specially trained and motivated rats for periods of two hundred hours, although similar .untreated boards were pierced within thirty-to sixty minutes.

  10. Lead induced testicular hypersensitivity in stressed rats.

    PubMed

    Saxena, D K; Lal, B; Srivastava, R S; Chandra, S V

    1990-01-01

    Rats were immobilized for 2 h and treated i.p. with lead Pb2+ (8 mg/kg/day) for 45 d to investigate the testicular effects of lead on rats kept under immobilization stress. Marked alteration in SDH. G6PDH activity, cholesterol and ascorbic acid contents and reduced sperm counts associated with marked pathological changes in the testis of rats were observed after combined treatment with lead and immobilization stress in comparison to either alone. An increase in the disturbances of testicular androgen synthesis seems to be responsible for enhanced testicular injury in lead induced stressed rats. PMID:2401350

  11. Automatic Training of Rat Cyborgs for Navigation

    PubMed Central

    Yu, Yipeng; Wu, Zhaohui; Xu, Kedi; Gong, Yongyue; Zheng, Nenggan; Zheng, Xiaoxiang; Pan, Gang

    2016-01-01

    A rat cyborg system refers to a biological rat implanted with microelectrodes in its brain, via which the outer electrical stimuli can be delivered into the brain in vivo to control its behaviors. Rat cyborgs have various applications in emergency, such as search and rescue in disasters. Prior to a rat cyborg becoming controllable, a lot of effort is required to train it to adapt to the electrical stimuli. In this paper, we build a vision-based automatic training system for rat cyborgs to replace the time-consuming manual training procedure. A hierarchical framework is proposed to facilitate the colearning between rats and machines. In the framework, the behavioral states of a rat cyborg are visually sensed by a camera, a parameterized state machine is employed to model the training action transitions triggered by rat's behavioral states, and an adaptive adjustment policy is developed to adaptively adjust the stimulation intensity. The experimental results of three rat cyborgs prove the effectiveness of our system. To the best of our knowledge, this study is the first to tackle automatic training of animal cyborgs. PMID:27436999

  12. Lead induced testicular hypersensitivity in stressed rats.

    PubMed

    Saxena, D K; Lal, B; Srivastava, R S; Chandra, S V

    1990-01-01

    Rats were immobilized for 2 h and treated i.p. with lead Pb2+ (8 mg/kg/day) for 45 d to investigate the testicular effects of lead on rats kept under immobilization stress. Marked alteration in SDH. G6PDH activity, cholesterol and ascorbic acid contents and reduced sperm counts associated with marked pathological changes in the testis of rats were observed after combined treatment with lead and immobilization stress in comparison to either alone. An increase in the disturbances of testicular androgen synthesis seems to be responsible for enhanced testicular injury in lead induced stressed rats.

  13. Hyperammonemia in anorectic tumor-bearing rats

    SciTech Connect

    Chance, W.T.; Cao, L.; Nelson, J.L.; Foley-Nelson, T.; Fischer, J.E.

    1988-01-01

    Plasma ammonia concentrations were significantly elevated by 150% in anorectic rats bearing methylcholanthrene sarcomas. Assessment of ammonia levels in blood draining these sarcomas indicated nearly a 20-fold increase as compared with venous blood in control rats, suggesting the tumor mass as the source of this increase in ammonia. Infusing increasing concentrations of ammonium salts produced anorexia and alterations in brain amino acids in normal rats that were similar to those observed in anorectic tumor-bearing rats. Therefore, these results suggest that ammonia released by tumor tissue may be an important factor in the etiology of cancer anorexia.

  14. Modulation of rat behaviour by using a rat-like robot.

    PubMed

    Shi, Qing; Ishii, Hiroyuki; Kinoshita, Shinichi; Takanishi, Atsuo; Okabayashi, Satoshi; Iida, Naritoshi; Kimura, Hiroshi; Shibata, Shigenobu

    2013-12-01

    In this paper, we study the response of a rat to a rat-like robot capable of generating different types of behaviour (stressful, friendly, neutral). Experiments are conducted in an open-field where a rat-like robot called WR-4 is put together with live rats. The activity level of each rat subject is evaluated by scoring its locomotor activity and frequencies of performing rearing (rising up on its hind limbs) and body grooming (body cuddling and head curling) actions, whereas the degree of preference of that is indicated by the robot-rat distance and the frequency of contacting WR-4. The moving speed and behaviour of WR-4 are controlled in real-time based on the feedback from rat motion. The activity level and degree of preference of rats for each experimental condition are analysed and compared to understand the influence of robot behaviour. The results of this study show that the activity level and degree of preference of the rat decrease when exposed to a stressful robot, and increase when the robot exhibit friendly behaviour, suggesting that a rat-like robot can modulate rat behaviour in a controllable, predictable way.

  15. Analysis of rat cytosolic 9-cis-retinol dehydrogenase activity and enzymatic characterization of rat ADHII.

    PubMed

    Popescu, G; Napoli, J L

    2000-01-01

    We report the characterization of two enzymes that catalyze NAD(+)-dependent 9-cis-retinol dehydrogenase activity in rat liver cystol. Alcohol dehydrogenase class I (ADHI) contributes > 80% of the NA D+-dependent 9-cis-retinol dehydrogenase activity recovered, whereas alcohol dehydrogenase class II (ADHII), not identified previously at the protein level, nor characterized enzymatically in rat, accounts for approximately 2% of the activity. Rat ADHII exhibits properties different from those described for human ADHII. Moreover, rat ADHII-catalyzed rates of ethanol dehydrogenation are markedly lower than octanol or retinoid dehydrogenation rates. Neither ethanol nor 4-methylpyrazole inhibits the 9-cis-retinol dehydrogenase activity of rat ADHII. We propose that ADHII represents the previously observed additional retinoid oxidation activity of rat liver cytosol which occurred in the presence of either ethanol or 4-methylpyrazole. We also show that human and rat ADHII differ considerably in enzymatic properties. PMID:10606766

  16. PBPK MODELING OF DELTAMETHRIN IN RATS

    EPA Science Inventory

    The pyrethroid pesticide deltamethrin is cleared nearly twice as rapidly in human liver microsomes compared to rat liver microsomes. A species difference such as this could influence the toxic potency of deltamethrin between rats and humans. PBPK modeling is a tool that can be ut...

  17. Eating pattern of morphine dependent rats.

    PubMed

    Yanaura, S; Suzuki, T

    1979-10-01

    To analyze the drug ingestion patterns of rats in the course of dependence development while on the drug-admixed food (DAF) method, an automatic food intake measuring apparatus was developed. Rats were put on morphine-admixed food, and the food ingestion patterns were recorded with the apparatus in the course of dependence development, during drug withdrawal and at the time of challenge with levallorphan. The naive rats ate the regular diet intermittently at night, and the eating time of morphine-treated rats was longer than that of naive rats. The treated rats also exhibited a frequent eating behavior after 4--5 days on the morphine treatment. During morphine withdrawal, the animal gradually ate the regular diet at about 1-hour intervals, even after evolvement of abstinence signs. When the morphine-dependent rats were given levallorphan, they neither ate nor approached to the food for the first 2--3 hours, but after this time, showed abrupt increases in these activities. Thus, the drug intake pattern of rats in the course of morphine dependence development suggests a correlation between the stage of development of physical dependence and the stage when the animals frequently eat the drug-admixed food.

  18. Same-Different Categorization in Rats

    ERIC Educational Resources Information Center

    Wasserman, Edward A.; Castro, Leyre; Freeman, John H.

    2012-01-01

    Same-different categorization is a fundamental feat of human cognition. Although birds and nonhuman primates readily learn same-different discriminations and successfully transfer them to novel stimuli, no such demonstration exists for rats. Using a spatial discrimination learning task, we show that rats can both learn to discriminate arrays of…

  19. Hypoglycaemic activity of Ocimum gratissimum in rats.

    PubMed

    Aguiyi, J C; Obi, C I; Gang, S S; Igweh, A C

    2000-08-01

    The hypoglycaemic effect of the methanolic extract of Ocimum gratissimum leaves was evaluated in normal and alloxan-induced diabetic rats. Intraperitoneal injection of the extract (400 mg/kg) significantly reduced plasma levels both in normal and diabetic rats by 56 and 68%, respectively. PMID:10925022

  20. Spatial Memory in Rats after 25 Hours

    ERIC Educational Resources Information Center

    Crystal, Jonathon D.; Babb, Stephanie J.

    2008-01-01

    We investigated the time course of spatial-memory decay in rats using an eight-arm radial maze. It is well established that performance remains high with retention intervals as long as 4 h, but declines to chance with a 24-h retention interval (Beatty, W. W., & Shavalia, D. A. (1980b). Spatial memory in rats: time course of working memory and…

  1. Stimulus Over-Selectivity in Rats

    ERIC Educational Resources Information Center

    Gibson, Evelyn; Reed, Phil

    2005-01-01

    The present study explored whether a similar phenomenon to stimulus over-selectivity occurred in rats, in the hope of establishing a non-human model for the autism. Rats were serially presented with two-15 seconds, two-element compound stimuli prior to the delivery of food, in an appetitive classical conditioning procedure. Each compound stimulus…

  2. Is fructose sweeter than glucose for rats?

    PubMed

    Ramirez, I

    1996-11-01

    Because it is generally thought that the intensity of the taste of fructose is greater than that of glucose for rats, it seemed surprising when sham-fed rats drank substantially less of a mixture of 6% fructose plus saccharin than of a mixture of 6% glucose plus saccharin. At least 3 different factors contribute to this effect. First, the taste of fructose is less attractive to rats than is the taste of glucose; sham-fed rats strongly preferred glucose over fructose (no saccharin was used in this experiment). The second factor is experience. Rats having substantial previous experience with glucose, but not with fructose, consistently preferred glucose over fructose. Conversely, rats having substantial previous experience with fructose, but not with glucose, initially showed no consistent preference but subsequently tended to prefer glucose. The third factor is an interaction between saccharin and the type of sugar. Rats given only one solution at a time drink approximately as much fructose as glucose when the solutions contain no saccharin. The addition of 0.25% saccharin to 6% glucose stimulated intake, whereas the addition of the same amount of saccharin to 6% fructose did not stimulate intake. As a result, rats ingested substantially more of a mixture of 0.25% saccharin plus 6% glucose than they did of a comparable mixture of saccharin and fructose, even though rats ingest similar amounts of fructose and glucose without saccharin in single-bottle tests. Because the differential effect of saccharin on intake appeared within 2 h in naive rats, and did not greatly change over a 3-day period, it is probably not attributable to conditioning. These results suggest that these sugars have qualitatively different tastes. PMID:8916185

  3. Mitochondrial DNA Phylogeography of the Norway Rat

    PubMed Central

    Song, Ying; Lan, Zhenjiang; Kohn, Michael H.

    2014-01-01

    Central Eastern Asia, foremost the area bordering northern China and Mongolia, has been thought to be the geographic region where Norway rats (Rattus norvegicus) have originated. However recent fossil analyses pointed to their origin in southern China. Moreover, whereas analyses of fossils dated the species' origin as ∼1.2–1.6 million years ago (Mya), molecular analyses yielded ∼0.5–2.9 Mya. Here, to study the geographic origin of the Norway rat and its spread across the globe we analyzed new and all published mitochondrial DNA cytochrome-b (cyt-b; N = 156) and D-loop (N = 212) sequences representing wild rats from four continents and select inbred strains. Our results are consistent with an origin of the Norway rat in southern China ∼1.3 Mya, subsequent prehistoric differentiation and spread in China and Asia from an initially weakly structured ancestral population, followed by further spread and differentiation across the globe during historic times. The recent spreading occurred mostly from derived European populations rather than from archaic Asian populations. We trace laboratory strains to wild lineages from Europe and North America and these represent a subset of the diversity of the rat; leaving Asian lineages largely untapped as a resource for biomedical models. By studying rats from Europe we made the observation that mtDNA diversity cannot be interpreted without consideration of pest control and, possibly, the evolution of rodenticide resistance. However, demographic models explored by forward-time simulations cannot fully explain the low mtDNA diversity of European rats and lack of haplotype sharing with their source from Asia. Comprehensive nuclear marker analyses of a larger sample of Norway rats representing the world are needed to better resolve the evolutionary history of wild rats and of laboratory rats, as well as to better understand the evolution of anticoagulant resistance. PMID:24586325

  4. Social exclusion intensifies anxiety-like behavior in adolescent rats.

    PubMed

    Lee, Hyunchan; Noh, Jihyun

    2015-05-01

    Social connection reduces the physiological reactivity to stressors, while social exclusion causes emotional distress. Stressful experiences in rats result in the facilitation of aversive memory and induction of anxiety. To determine the effect of social interaction, such as social connection, social exclusion and equality or inequality, on emotional change in adolescent distressed rats, the emotional alteration induced by restraint stress in individual rats following exposure to various social interaction circumstances was examined. Rats were assigned to one of the following groups: all freely moving rats, all rats restrained, rats restrained in the presence of freely moving rats and freely moving rats with a restrained rat. No significant difference in fear-memory and sucrose consumption between all groups was found. Change in body weight significantly increased in freely moving rats with a restrained rat, suggesting that those rats seems to share the stressful experience of the restrained rat. Interestingly, examination of the anxiety-like behavior revealed only rats restrained in the presence of freely moving rats to have a significant increase, suggesting that emotional distress intensifies in positions of social exclusion. These results demonstrate that unequally excluded social interaction circumstances could cause the amplification of distressed status and anxiety-related emotional alteration.

  5. Acute myocardial infarction in rats.

    PubMed

    Wu, Yewen; Yin, Xing; Wijaya, Cori; Huang, Ming-He; McConnell, Bradley K

    2011-01-01

    With heart failure leading the cause of death in the USA (Hunt), biomedical research is fundamental to advance medical treatments for cardiovascular diseases. Animal models that mimic human cardiac disease, such as myocardial infarction (MI) and ischemia-reperfusion (IR) that induces heart failure as well as pressure-overload (transverse aortic constriction) that induces cardiac hypertrophy and heart failure (Goldman and Tarnavski), are useful models to study cardiovascular disease. In particular, myocardial ischemia (MI) is a leading cause for cardiovascular morbidity and mortality despite controlling certain risk factors such as arteriosclerosis and treatments via surgical intervention (Thygesen). Furthermore, an acute loss of the myocardium following myocardial ischemia (MI) results in increased loading conditions that induces ventricular remodeling of the infarcted border zone and the remote non-infarcted myocardium. Myocyte apoptosis, necrosis and the resultant increased hemodynamic load activate multiple biochemical intracellular signaling that initiates LV dilatation, hypertrophy, ventricular shape distortion, and collagen scar formation. This pathological remodeling and failure to normalize the increased wall stresses results in progressive dilatation, recruitment of the border zone myocardium into the scar, and eventually deterioration in myocardial contractile function (i.e. heart failure). The progression of LV dysfunction and heart failure in rats is similar to that observed in patients who sustain a large myocardial infarction, survive and subsequently develops heart failure (Goldman). The acute myocardial infarction (AMI) model in rats has been used to mimic human cardiovascular disease; specifically used to study cardiac signaling mechanisms associated with heart failure as well as to assess the contribution of therapeutic strategies for the treatment of heart failure. The method described in this report is the rat model of acute myocardial

  6. [Nosema sp. in white rats].

    PubMed

    Grobov, O F; Karakuiumchiani, M K; Orlova-Sokol'skaia, I A

    1975-01-01

    In 14 days after the intraperitoneal infection of mice with 30% brain emulsion of white mice or of newly-born rats in the peritoneal liquid there were found spores of Nosema sp. 5.37 plus or minus 0.88 x 3.04 plus or minus 0.07 in size. The subsequent attempts to passage this organism on the mice by adminestering into them the suspension from the brain and internal organs of infected animals yielded ho results. The material for diagnosing on microsporidians of mammals is being discussed.

  7. Anxiolytic Treatment Impairs Helping Behavior in Rats.

    PubMed

    Ben-Ami Bartal, Inbal; Shan, Haozhe; Molasky, Nora M R; Murray, Teresa M; Williams, Jasper Z; Decety, Jean; Mason, Peggy

    2016-01-01

    Despite decades of research with humans, the biological mechanisms that motivate an individual to help others remain poorly understood. In order to investigate the roots of pro-sociality in mammals, we established the helping behavior test, a paradigm in which rats are faced with a conspecific trapped in a restrainer that can only be opened from the outside. Over the course of repeated test sessions, rats exposed to a trapped cagemate learn to open the door to the restrainer, thereby helping the trapped rat to escape (Ben-Ami Bartal et al., 2011). The discovery of this natural behavior provides a unique opportunity to probe the motivation of rodent helping behavior, leading to a deeper understanding of biological influences on human pro-sociality. To determine if an affective response motivates door-opening, rats receiving midazolam, a benzodiazepine anxiolytic, were tested in the helping behavior test. Midazolam-treated rats showed less helping behavior than saline-treated rats or rats receiving no injection. Yet, midazolam-treated rats opened a restrainer containing chocolate, highlighting the socially specific effects of the anxiolytic. To determine if midazolam interferes with helping through a sympatholytic effect, the peripherally restricted beta-adrenergic receptor antagonist nadolol was administered; nadolol did not interfere with helping. The corticosterone response of rats exposed to a trapped cagemate was measured and compared to the rats' subsequent helping behavior. Rats with the greatest corticosterone responses showed the least helping behavior and those with the smallest responses showed the most consistent helping at the shortest latency. These results are discussed in terms of their implications for the interaction between stress and pro-social behavior. Finally, we observed that door-opening appeared to be reinforcing. A novel analytical tool was designed to interrogate the pattern of door-opening for signs that a rat's behavior on one session

  8. Effects of Land Use on Plague (Yersinia pestis) Activity in Rodents in Tanzania

    PubMed Central

    McCauley, Douglas J.; Salkeld, Daniel J.; Young, Hillary S.; Makundi, Rhodes; Dirzo, Rodolfo; Eckerlin, Ralph P.; Lambin, Eric F.; Gaffikin, Lynne; Barry, Michele; Helgen, Kristofer M.

    2015-01-01

    Understanding the effects of land-use change on zoonotic disease risk is a pressing global health concern. Here, we compare prevalence of Yersinia pestis, the etiologic agent of plague, in rodents across two land-use types—agricultural and conserved—in northern Tanzania. Estimated abundance of seropositive rodents nearly doubled in agricultural sites compared with conserved sites. This relationship between land-use type and abundance of seropositive rodents is likely mediated by changes in rodent and flea community composition, particularly via an increase in the abundance of the commensal species, Mastomys natalensis, in agricultural habitats. There was mixed support for rodent species diversity negatively impacting Y. pestis seroprevalence. Together, these results suggest that land-use change could affect the risk of local transmission of plague, and raise critical questions about transmission dynamics at the interface of conserved and agricultural habitats. These findings emphasize the importance of understanding disease ecology in the context of rapidly proceeding landscape change. PMID:25711606

  9. Novel Arenavirus Sequences in Hylomyscus sp. and Mus (Nannomys) setulosus from Côte d'Ivoire: Implications for Evolution of Arenaviruses in Africa

    PubMed Central

    Kouassi, Stéphane K.; Fichet-Calvet, Elisabeth; Becker-Ziaja, Beate; Rieger, Toni; Ölschläger, Stephan; Dosso, Hernri; Denys, Christiane; ter Meulen, Jan; Akoua-Koffi, Chantal; Günther, Stephan

    2011-01-01

    This study aimed to identify new arenaviruses and gather insights in the evolution of arenaviruses in Africa. During 2003 through 2005, 1,228 small mammals representing 14 different genera were trapped in 9 villages in south, east, and middle west of Côte d'Ivoire. Specimens were screened by pan-Old World arenavirus RT-PCRs targeting S and L RNA segments as well as immunofluorescence assay. Sequences of two novel tentative species of the family Arenaviridae, Menekre and Gbagroube virus, were detected in Hylomyscus sp. and Mus (Nannomys) setulosus, respectively. Arenavirus infection of Mus (Nannomys) setulosus was also demonstrated by serological testing. Lassa virus was not found, although 60% of the captured animals were Mastomys natalensis. Complete S RNA and partial L RNA sequences of the novel viruses were recovered from the rodent specimens and subjected to phylogenetic analysis. Gbagroube virus is a closely related sister taxon of Lassa virus, while Menekre virus clusters with the Ippy/Mobala/Mopeia virus complex. Reconstruction of possible virus–host co-phylogeny scenarios suggests that, within the African continent, signatures of co-evolution might have been obliterated by multiple host-switching events. PMID:21695269

  10. Mapping the zoonotic niche of Lassa fever in Africa

    PubMed Central

    Mylne, Adrian Q. N.; Pigott, David M.; Longbottom, Joshua; Shearer, Freya; Duda, Kirsten A.; Messina, Jane P.; Weiss, Daniel J.; Moyes, Catherine L.; Golding, Nick; Hay, Simon I.

    2015-01-01

    Background Lassa fever is a viral haemorrhagic illness responsible for disease outbreaks across West Africa. It is a zoonosis, with the primary reservoir species identified as the Natal multimammate mouse, Mastomys natalensis. The host is distributed across sub-Saharan Africa while the virus' range appears to be restricted to West Africa. The majority of infections result from interactions between the animal reservoir and human populations, although secondary transmission between humans can occur, particularly in hospital settings. Methods Using a species distribution model, the locations of confirmed human and animal infections with Lassa virus (LASV) were used to generate a probabilistic surface of zoonotic transmission potential across sub-Saharan Africa. Results Our results predict that 37.7 million people in 14 countries, across much of West Africa, live in areas where conditions are suitable for zoonotic transmission of LASV. Four of these countries, where at-risk populations are predicted, have yet to report any cases of Lassa fever. Conclusions These maps act as a spatial guide for future surveillance activities to better characterise the geographical distribution of the disease and understand the anthropological, virological and zoological interactions necessary for viral transmission. Combining this zoonotic niche map with detailed patient travel histories can aid differential diagnoses of febrile illnesses, enabling a more rapid response in providing care and reducing the risk of onward transmission. PMID:26085474

  11. Lassa virus isolates from Mali and the Ivory Coast represent an emerging fifth lineage.

    PubMed

    Manning, John T; Forrester, Naomi; Paessler, Slobodan

    2015-01-01

    Previous imported cases of Lassa fever (LF) into the United Kingdom from the Ivory Coast and Mali, as well as the detection of Lassa virus (LASV) among the Mastomys natalensis population within Mali has led to the suggestion that the endemic area for LF is expanding. Initial phylogenetic analyses arrange isolates from Mali and the Ivory Coast separately from the classical lineage IV isolates taken from Sierra Leone, Guinea, and Liberia. The availability of full genome sequences continues to increase, allowing for a more complete phylogenetic comparison of the isolates from Mali and the Ivory Coast to the other existing isolates. In this study, we utilized a Bayesian approach to infer the demographic histories of each LASV isolate for which the full sequence was available. Our results indicate that the isolates from Mali and the Ivory Coast group separately from the isolates of lineage IV, comprising a distinct fifth lineage. The split between lineages IV and V is estimated to have occurred around 200-300 years ago, which coincides with the colonial period of West Africa.

  12. Prevalence and diversity of small mammal-associated Bartonella species in rural and urban Kenya.

    PubMed

    Halliday, Jo E B; Knobel, Darryn L; Agwanda, Bernard; Bai, Ying; Breiman, Robert F; Cleaveland, Sarah; Njenga, M Kariuki; Kosoy, Michael

    2015-03-01

    Several rodent-associated Bartonella species are human pathogens but little is known about their epidemiology. We trapped rodents and shrews around human habitations at two sites in Kenya (rural Asembo and urban Kibera) to determine the prevalence of Bartonella infection. Bartonella were detected by culture in five of seven host species. In Kibera, 60% of Rattus rattus were positive, as compared to 13% in Asembo. Bartonella were also detected in C. olivieri (7%), Lemniscomys striatus (50%), Mastomys natalensis (43%) and R. norvegicus (50%). Partial sequencing of the citrate synthase (gltA) gene of isolates showed that Kibera strains were similar to reference isolates from Rattus trapped in Asia, America, and Europe, but that most strains from Asembo were less similar. Host species and trapping location were associated with differences in infection status but there was no evidence of associations between host age or sex and infection status. Acute febrile illness occurs at high incidence in both Asembo and Kibera but the etiology of many of these illnesses is unknown. Bartonella similar to known human pathogens were detected in small mammals at both sites and investigation of the ecological determinants of host infection status and of the public health significance of Bartonella infections at these locations is warranted. PMID:25781015

  13. Innocuity studies of SAG-2 oral rabies vaccine in various Zimbabwean wild non-target species.

    PubMed

    Bingham, J; Schumacher, C L; Aubert, M F; Hill, F W; Aubert, A

    1997-06-01

    The SAG-2 modified live rabies vaccine was tested for innocuity when administered by the oral route in several potential wild non-target bait-consuming species, as follows: ten chacma baboons (Papio ursinus), six African civets (Civettictis civetta), six slender mongooses (Galerella sanguinea), six honey badgers (Mellivora capensis), six large-spotted genets (Genetta tigrina), 39 multi-mammate mice (Mastomys natalensis), 26 bushveld gerbils (Tatera leucogaster) and six pied crows (Corvus albus). At least 9.0 log10 median tissue culture infectious doses (TCID50), given in a volume of 1 ml, was administered orally to each of the animals, except the rodents which received 8.0 log10 TCID50, given in 0.1 ml. All the animals were observed for not < 90 days for signs of vaccine-induced rabies. Most of the species were also tested for vaccine virus replication in the oral cavity and persistent virus infection in the brain, salivary gland and tonsil. None of the animals died of rabies and no persistent infection was found. Rabies virus which was pathologically and serotypically indistinguishable from the vaccinal strain was isolated from the saliva of one genet 1 day after vaccine administration. From this study it was concluded that SAG-2 rabies vaccine would be safe for use in most situations where oral vaccination campaigns for jackals are required in Zimbabwe. PMID:9261938

  14. Small mammal distribution and diversity in a plague endemic area in West Usambara Mountains, Tanzania.

    PubMed

    Ralaizafisoloarivony, Njaka A; Kimaro, Didas N; Kihupi, Nganga I; Mulungu, Loth S; Leirs, Herwig; Msanya, Balthazar M; Deckers, Jozef A; Gulinck, Hubert

    2014-07-01

    Small mammals play a role in plague transmission as hosts in all plague endemic areas. Information on distribution and diversity of small mammals is therefore important for plague surveillance and control in such areas. The objective of this study was to investigate small mammals' diversity and their distribution in plague endemic area in the West Usambara Mountains in north-eastern Tanzania. Landsat images and field surveys were used to select trapping locations in different landscapes. Three landscapes with different habitats were selected for trapping of small mammals. Three types of trap were used in order to maximise the number of species captured. In total, 188 animals and thirteen species were captured in 4,905 trap nights. Praomys delectorum and Mastomys natalensis both reported as plague hosts comprised 50% of all the animals trapped. Trap success increased with altitude. Species diversity was higher in plantation forest followed by shrub, compared to other habitats, regardless of landscape type. It would therefore seem that chances of plague transmission from small mammals to humans are much higher under shrub, natural and plantation forest habitats.

  15. Plague in Tanzania: an overview.

    PubMed

    Ziwa, Michael H; Matee, Mecky I; Hang'ombe, Bernard M; Lyamuya, Eligius F; Kilonzo, Bukheti S

    2013-10-01

    Human plague remains a public health concern in Tanzania despite its quiescence in most foci for years, considering the recurrence nature of the disease. Despite the long-standing history of this problem, there have not been recent reviews of the current knowledge on plague in Tanzania. This work aimed at providing a current overview of plague in Tanzania in terms of its introduction, potential reservoirs, possible causes of plague persistence and repeated outbreaks in the country. Plague is believed to have been introduced to Tanzania from the Middle East through Uganda with the first authentication in 1886. Xenopsylla brasiliensis, X. cheopis, Dinopsyllus lypusus, and Pulex irritans are among potential vectors while Lophuromys spp, Praomys delectorum, Graphiurus murinus, Lemniscomys striatus, Mastomys natalensis, and Rattus rattus may be the potential reservoirs. Plague persistence and repeated outbreaks in Tanzania are likely to be attributable to a complexity of factors including cultural, socio-economical, environmental and biological. Minimizing or preventing people's proximity to rodents is probably the most effective means of preventing plague outbreaks in humans in the future. In conclusion, much has been done on plague diagnosis in Tanzania. However, in order to achieve new insights into the features of plague epidemiology in the country, and to reorganize an effective control strategy, we recommend broader studies that will include the ecology of the pathogen, vectors and potential hosts, identifying the reservoirs, dynamics of infection and landscape ecology.

  16. Vegetation habitats and small mammals in a plague endemic area in Western Usambara Mountains, Tanzania.

    PubMed

    Ralaizafisoloarivony, Njaka A; Kimaro, Didas N; Kihupi, Nganga I; Mulungu, Loth S; Leirs, Herwig; Msanya, Balthazar M; Deckers, Jozef A; Gulinck, Hubert

    2014-07-01

    Human plague still exists in different parts of the world, including some landscapes in north-eastern Tanzania. Wherever the hotspot of plague, small mammals seem to play a key role as host. The objective of this study was to investigate the relationship between vegetation habitats types and small mammals in a plague endemic area of Lushoto District in Tanzania. A combination of field survey and Landsat images was used to identify the vegetation habitats. Small mammals were trapped in the mapped vegetation units, and identified. In total, six main types of vegetation habitats were investigated. A total of 13 small mammal species, potentially related to plague were trapped. Results show that annual cultivated crops habitat accounted for 80% of Mastomys natalensis while natural forest accounted for 60% of Praomys delectorum. These findings have shed new light on the diversity of rodents in different habitats of natural and semi-natural vegetations, and agricultural crops in the study area, which is an important intermediate step in unravelling the complex human plague system.

  17. Prevalence and diversity of small mammal-associated Bartonella species in rural and urban Kenya.

    PubMed

    Halliday, Jo E B; Knobel, Darryn L; Agwanda, Bernard; Bai, Ying; Breiman, Robert F; Cleaveland, Sarah; Njenga, M Kariuki; Kosoy, Michael

    2015-03-01

    Several rodent-associated Bartonella species are human pathogens but little is known about their epidemiology. We trapped rodents and shrews around human habitations at two sites in Kenya (rural Asembo and urban Kibera) to determine the prevalence of Bartonella infection. Bartonella were detected by culture in five of seven host species. In Kibera, 60% of Rattus rattus were positive, as compared to 13% in Asembo. Bartonella were also detected in C. olivieri (7%), Lemniscomys striatus (50%), Mastomys natalensis (43%) and R. norvegicus (50%). Partial sequencing of the citrate synthase (gltA) gene of isolates showed that Kibera strains were similar to reference isolates from Rattus trapped in Asia, America, and Europe, but that most strains from Asembo were less similar. Host species and trapping location were associated with differences in infection status but there was no evidence of associations between host age or sex and infection status. Acute febrile illness occurs at high incidence in both Asembo and Kibera but the etiology of many of these illnesses is unknown. Bartonella similar to known human pathogens were detected in small mammals at both sites and investigation of the ecological determinants of host infection status and of the public health significance of Bartonella infections at these locations is warranted.

  18. Advanced vaccine candidates for Lassa fever.

    PubMed

    Lukashevich, Igor S

    2012-11-01

    Lassa virus (LASV) is the most prominent human pathogen of the Arenaviridae. The virus is transmitted to humans by a rodent reservoir, Mastomys natalensis, and is capable of causing lethal Lassa Fever (LF). LASV has the highest human impact of any of the viral hemorrhagic fevers (with the exception of Dengue Fever) with an estimated several hundred thousand infections annually, resulting in thousands of deaths in Western Africa. The sizeable disease burden, numerous imported cases of LF in non-endemic countries, and the possibility that LASV can be used as an agent of biological warfare make a strong case for vaccine development. Presently there is no licensed vaccine against LF or approved treatment. Recently, several promising vaccine candidates have been developed which can potentially target different groups at risk. The purpose of this manuscript is to review the LASV pathogenesis and immune mechanisms involved in protection. The current status of pre-clinical development of the advanced vaccine candidates that have been tested in non-human primates will be discussed. Major scientific, manufacturing, and regulatory challenges will also be considered.

  19. Spatial Segregation between Invasive and Native Commensal Rodents in an Urban Environment: A Case Study in Niamey, Niger

    PubMed Central

    Garba, Madougou; Dalecky, Ambroise; Kadaoure, Ibrahima; Kane, Mamadou; Hima, Karmadine; Veran, Sophie; Gagare, Sama; Gauthier, Philippe; Tatard, Caroline; Rossi, Jean-Pierre; Dobigny, Gauthier

    2014-01-01

    Invasive rodents have been responsible for the diffusion worldwide of many zoonotic agents, thus representing major threats for public health. Cities are important hubs for people and goods exchange and are thus expected to play a pivotal role in invasive commensal rodent dissemination. Yet, data about urban rodents' ecology, especially invasive vs. native species interactions, are dramatically scarce. Here, we provide results of an extensive survey of urban rodents conducted in Niamey, Niger, depicting the early stages of rodent bioinvasions within a city. We explore the species-specific spatial distributions throughout the city using contrasted approaches, namely field sampling, co-occurrence analysis, occupancy modelling and indicator geostatistics. We show that (i) two species (i.e. rural-like vs. truly commensal) assemblages can be identified, and that (ii) within commensal rodents, invasive (Rattus rattus and Mus musculus) and native (Mastomys natalensis) species are spatially segregated. Moreover, several pieces of arguments tend to suggest that these exclusive distributions reflect an ongoing native-to-invasive species turn over. The underlying processes as well as the possible consequences for humans are discussed. PMID:25379785

  20. Electroencephalographic changes in albino rats subjected to stress

    NASA Technical Reports Server (NTRS)

    Mercier, J.; Assouline, G.; Fondarai, J.

    1980-01-01

    Twenty one albino Wistar rats were subjected to stress for 7 hours. There was a significant difference in the slopes of regression lines for 7 nonulcerous rats and those for 14 ulcerous rats. Nonulcerous rats subjected to stress showed greater EEG curve synchronization than did ulcerous rats. If curve synchronization can be equated to a relaxed state, it may therefore be possible to explain the protective action of hypnotics, tranquilizers and analgesics on ulcers.

  1. Persistent Seoul virus infection in Lewis rats.

    PubMed

    Compton, S R; Jacoby, R O; Paturzo, F X; Smith, A L

    2004-07-01

    Mechanistic studies of hantavirus persistence in rodent reservoirs have been limited by the lack of a versatile animal model. This report describes findings from experimental infection of inbred Lewis rats with Seoul virus strain 80-39. Rats inoculated with virus intraperitoneally at 6 days of age became persistently infected without clinical signs. Tissues from Seoul virus-inoculated 6-day-old rats were assessed at 6, 9, and 12 weeks post-inoculation for viral RNA by RT-PCR and in situ hybridization (ISH) and for infectious virus by inoculation of Vero E6 cells. Virus was isolated from lung and kidney of infected rats at 6 weeks and viral RNA was detected in lung, kidney, pancreas, salivary gland, brain, spleen, liver and skin at 6, 9 and 12 weeks. Rats inoculated with Seoul virus intraperitoneally at 10 or 21 days of age became infected without clinical signs but had low to undetectable levels of viral RNA in tissues at 6 weeks post-inoculation. ISH identified vascular smooth muscle and endothelial cells as common sites of persistent infection. Cultured rat smooth muscle cells and to a lesser extent cultured endothelial cells also were susceptible to Seoul virus infection. Pancreatic infection resulted in insulitis with associated hyperglycemia. These studies demonstrate that infant Lewis rats are uniformly susceptible to asymptomatic persistent Seoul virus infection. Additionally, they offer opportunities for correlative in vivo and in vitro study of Seoul virus interactions in host cell types that support persistent infection.

  2. Total parenteral nutrition in diabetic rats

    SciTech Connect

    Norcross, E.D.; Stein, T.P.

    1986-03-01

    Parenteral Nutrition with hypertonic glucose is frequently given to diabetic patients. Large amounts of insulin can be required. The purpose of this investigation was to develop a totally parenterally nourished diabetic rat model. 200 g Female Sprague Dawley rats were made diabetic by i.v. injection of streptozotocin (50 mg/kg). Rats were then allowed to recover for at least 1 week before undergoing surgical insertion of a central venous catheter for parenteral feeding. TPN was begun 3 days after surgery. Prior to this they were allowed unlimited access to food and water. Control (non-streptozotocin treated) rats were run at the same time. Protein turnover was investigated by using /sup 15/N glycine. Preliminary results: diabetic rats given mostly fat as a calorie source survived well in the absence of exogenous insulin whereas those that were given glucose only as their non-protein calorie source showed poor survival even with exogenous insulin. N balance and protein turnover in the lipid treated diabetic rats were comparable to the non-diabetic control rats.

  3. Altered proportions of RCS-rat eyes.

    PubMed

    Schreckenberger, M; Eichhorn, M; Gottanka, J; Döbig, C; Lütjen-Drecoll, E

    1994-10-01

    The growth pattern of RCS-rat eyes with hereditary retinal degeneration was analysed morphometrically, evaluating midsagittal sections of the entire globe and sections of the chamber angle region. No changes of the axial diameter of RCS-rat eyes were found if compared with eyes of age-matched controls. There were, however, characteristic proportional changes in the anterior eye segment of RCS rats. The distance between the peripheral end of Descemet's membrane (DM) and both the posterior end of Schlemm's canal and the ora serrata were significantly elongated indicating that this region might be most susceptible to growth factors. The length of the posterior globe up to the level of the ora serrata was shorter in RCS rats than in control rats. In addition, in RCS-rat eyes the pars plana was significantly elongated and the pars plicata shortened. Ultrastructural changes of ciliary epithelium were not seen before 7 months of age in RCS rats. They were only present in those parts of the circumference in which the stromal capillaries also revealed structural changes. The ciliary epithelial alterations were therefore considered secondary to narrowing or rarefication in the adjacent blood vessels.

  4. Embryolethality of butyl benzyl phthalate in rats

    SciTech Connect

    Ema, N.; Itami, T.; Kawasaki, H. )

    1991-03-15

    The developmental toxicity of butyl benzyl phthalate (BBP) was studied in Wistar rats. Pregnant rats were given BBP at a dosage of 0, 0.25, 0.5, 1.0 or 2.0% in the diet from day 0 to day 20 of pregnancy. Morphological examinations of the fetuses revealed no evidence of teratogenesis. In the 2.0% group, all dams exhibited complete resorption of all the implanted embryos, and their food consumption, body weight gain and adjusted weight gain during pregnancy were markedly lowered. To determine whether the embryolethality was the result of reduced food consumption during pregnancy, a pair-feeding study was performed in which the pregnant rats received the same amount of diet consumed by the 2.0% BBP-treated pregnant rats. The pair-fed and 2.0 % BBP-treated pregnant rats showed significant and comparable reductions in the adjusted weight gain. The number of live fetuses was lowered in the pair-fed group. However, the complete resorption of all the implanted embryos was not found in any of the pair-fed pregnant rats. The data suggest that the embryolethality observed in the 2.0 % BBP-treated pregnant rats is attributable to the effects o dietary BBP.

  5. Wood rats and kangaroo rats: potential reservoirs of the Lyme disease spirochete in California.

    PubMed

    Lane, R S; Brown, R N

    1991-05-01

    The etiologic agent of Lyme disease, Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner, was isolated repeatedly from dusky-footed wood rats, Neotoma fuscipes Baird, and California kangaroo rats, Dipodomys californicus Merriam, in northern California. All animals were collected in a region endemic for Lyme disease but for which the natural reservoir of B. burgdorferi was unknown. Similar attempts to isolate spirochetes from lizards, other species of rodents, jack rabbits, and deer between 1987 and 1991 were unsuccessful. Spirochetes isolated from wood rats and kangaroo rats were antigenically similar to strains of B. burgdorferi that had been isolated previously from the western black-legged tick, Ixodes pacificus Cooley & Kohls, in California. Similar enzootic cycles involving wood rats or kangaroo rats should be sought in other regions of the United States where the reservoirs of this spirochete are unknown.

  6. Methaqualone metabolism by rat liver microsomes.

    PubMed

    Manowitz, P; Shull, C M

    1976-01-01

    A rat hepatic microsomal system has been established which metabolizes methaqualone. The microsomes are obtained from livers of rats treated with phenobarbital. The methaqualone is dissolved in polyethylene glycol-200 prior to addition to the incubation mixture. A comparison is made between the metabolites obtained in this in vitro system and metabolites obtained from urines of phenobarbital treated rats injected with methaqualone. The same two and sometimes three metabolites, as determined by thin layer and gas liquid chromatography, were found in both the complete microsomal incubation system and the urines.

  7. Skeletal muscle metabolism in hypokinetic rats

    NASA Technical Reports Server (NTRS)

    Tischler, M. E.

    1984-01-01

    Muscle growth, protein metabolism, and amino acid metabolism were studied in various groups of rats. Certain groups were adrenaliectomized; some rats were suspended while others (the controls) were weight bearing. Results show that: (1) metabolic changes in the extensor digitorum longus muscle of suspended rats are due primarily to increased circulating glucocorticoids; (2) metabolic changes in the soleus muscle due to higher steroid levels are probably potentiated by greater numbers of steroid receptors; and (3) not all metabolic responses of the soleus muscle to unloading are due to the elevated levels of glucocorticoids or the increased sensitivity of this muscle to these hormones.

  8. Establishment of a novel dwarf rat strain: cartilage calcification insufficient (CCI) rats.

    PubMed

    Tanaka, Masami; Watanabe, Minoru; Yokomi, Izuru; Matsumoto, Naoki; Sudo, Katsuko; Satoh, Hitoshi; Igarashi, Tsuneo; Seki, Azusa; Amano, Hitoshi; Ohura, Kiyoshi; Ryu, Kakei; Shibata, Shunichi; Nagayama, Motohiko; Tanuma, Jun-ichi

    2015-01-01

    Rats with dwarfism accompanied by skeletal abnormalities, such as shortness of the limbs, tail, and body (dwarf rats), emerged in a Jcl-derived Sprague-Dawley rat colony maintained at the Institute for Animal Experimentation, St. Marianna University Graduate School of Medicine. Since the dwarfism was assumed to be due to a genetic mutation based on its frequency, we bred the dwarf rats and investigated their characteristics in order to identify the causative factors of their phenotypes and whether they could be used as a human disease model. One male and female that produced dwarf progeny were selected, and reproduction was initiated by mating the pair. The incidence of dwarfism was 25.8% among the resultant litter, and dwarfism occurred in both genders, suggesting that it was inherited in an autosomal recessive manner. At 12 weeks of age, the body weights of the male and female dwarf rats were 40% and 57% of those of the normal rats, respectively. In soft X-ray radiographic and histological examinations, shortening and hypoplasia of the long bones, such as the tibia and femur, were observed, which were suggestive of endochondral ossification abnormalities. An immunohistochemical examination detected an aggrecan synthesis disorder, which might have led to delayed calcification and increased growth plate thickening in the dwarf rats. We hypothesized that the principal characteristics of the dwarf rats were systemically induced by insufficient cartilage calcification in their long bones; thus, we named them cartilage calcification insufficient (CCI) rats.

  9. Rats are the smart choice: Rationale for a renewed focus on rats in behavioral genetics.

    PubMed

    Parker, Clarissa C; Chen, Hao; Flagel, Shelly B; Geurts, Aron M; Richards, Jerry B; Robinson, Terry E; Solberg Woods, Leah C; Palmer, Abraham A

    2014-01-01

    Due in part to their rich behavioral repertoire rats have been widely used in behavioral studies of drug abuse-related traits for decades. However, the mouse became the model of choice for researchers exploring the genetic underpinnings of addiction after the first mouse study was published demonstrating the capability of engineering the mouse genome through embryonic stem cell technology. The sequencing of the mouse genome and more recent re-sequencing of numerous inbred mouse strains have further cemented the status of mice as the premier mammalian organism for genetic studies. As a result, many of the behavioral paradigms initially developed and optimized for rats have been adapted to mice. However, numerous complex and interesting drug abuse-related behaviors that can be studied in rats are very difficult or impossible to adapt for use in mice, impeding the genetic dissection of those traits. Now, technological advances have removed many of the historical limitations of genetic studies in rats. For instance, the rat genome has been sequenced and many inbred rat strains are now being re-sequenced and outbred rat stocks are being used to fine-map QTLs. In addition, it is now possible to create "knockout" rats using zinc finger nucleases (ZFN), transcription activator-like effector nucleases (TALENs) and related techniques. Thus, rats can now be used to perform quantitative genetic studies of sophisticated behaviors that have been difficult or impossible to study in mice. This article is part of a Special Issue entitled 'NIDA 40th Anniversary Issue'.

  10. Both acute and chronic buspirone treatments have different effects on regional 5-HT synthesis in Flinders Sensitive Line rats (a rat model of depression) than in control rats

    PubMed Central

    Nishi, Kyoko; Kanemaru, Kazuya; Hasegawa, Shu; Watanabe, Arata; Diksic, Mirko

    2009-01-01

    The main objective of this investigation was to evaluate the effects of buspirone, a 5-HT1A agonist with some partial agonist properties and also an antidepressant, on regional 5-HT synthesis in Flinders Sensitive Line (FSL) rats (“depressed”), and to compare the effects to the Flinders Resistant Line (FRL) control rats (not “depressed”). In addition results were compared to those previously reported in normal Sprague-Dawley (SPD) rats (normal control). Serotonin synthesis in both FSL and FRL rats was measured following acute and chronic treatments with buspirone. Both of these strains were derived from the SPD rats. No direct comparison was done between the FSL saline and FRL saline groups, or the FSL buspirone and FRL buspirone groups, because the objective of the studies was to evaluate effects of buspirone in these two strains. The results show that acute treatment with buspirone elevates 5-HT synthesis throughout the brain in the FRL rats. In the FSL rats, there were reductions in some brain regions (e.g., dorsal and median raphe, amygdala, anterior olfactory nucleus, substantia nigra reticulate), while in other regions, there were increases in the synthesis observed (e.g., frontal, parietal, visual and somatosensory cortices, ventral hippocampus). In twenty out of the thirty brain regions investigated in the FSL rats, there was no significant change in the synthesis following acute buspirone treatment. During the chronic treatment, buspirone produced a significant reduction of 5-HT synthesis in fifteen out of thirty brain regions in the FRL rats. In the FSL rats, buspirone produced a significant elevation of the synthesis in ten out of thirty brain regions. In both the FSL and FRL rats, buspirone produced rather different effects than those reported previously for SPD (normal) rats. The acute effect in the FSL rats was somewhat similar to the effect reported previously for the SPD rats, while in the FRL rats, the acute buspirone treatment produced an

  11. Rat Bite Fever Resembling Rheumatoid Arthritis.

    PubMed

    Akter, Ripa; Boland, Paul; Daley, Peter; Rahman, Proton; Al Ghanim, Nayef

    2016-01-01

    Rat bite fever is rare in Western countries. It can be very difficult to diagnose as blood cultures are typically negative and a history of rodent exposure is often missed. Unless a high index of suspicion is maintained, the associated polyarthritis can be mistaken for rheumatoid arthritis. We report a case of culture-positive rat bite fever in a 46-year-old female presenting with fever and polyarthritis. The clinical presentation mimicked rheumatoid arthritis. Infection was complicated by discitis, a rare manifestation. We discuss the diagnosis and management of this rare zoonotic infection. We also review nine reported cases of rat bite fever, all of which had an initial presumptive diagnosis of a rheumatological disorder. Rat bite fever is a potentially curable infection but can have a lethal course if left untreated. PMID:27366177

  12. Rat Bite Fever Resembling Rheumatoid Arthritis

    PubMed Central

    Akter, Ripa; Boland, Paul; Daley, Peter; Rahman, Proton; Al Ghanim, Nayef

    2016-01-01

    Rat bite fever is rare in Western countries. It can be very difficult to diagnose as blood cultures are typically negative and a history of rodent exposure is often missed. Unless a high index of suspicion is maintained, the associated polyarthritis can be mistaken for rheumatoid arthritis. We report a case of culture-positive rat bite fever in a 46-year-old female presenting with fever and polyarthritis. The clinical presentation mimicked rheumatoid arthritis. Infection was complicated by discitis, a rare manifestation. We discuss the diagnosis and management of this rare zoonotic infection. We also review nine reported cases of rat bite fever, all of which had an initial presumptive diagnosis of a rheumatological disorder. Rat bite fever is a potentially curable infection but can have a lethal course if left untreated. PMID:27366177

  13. 2011 Desert RATS Sights and Sounds

    NASA Video Gallery

    Watch scenes from the 2011 Desert Research and Technology Studies (RATS) analog field test, as NASA scientists and engineers drive the Space Exploration Vehicle, assemble equipment in the Habitat D...

  14. Hypergravity induced prolactin surge in female rats

    NASA Technical Reports Server (NTRS)

    Megory, E.; Oyama, J.

    1985-01-01

    Acute initial exposure to hypergravity (HG) was previously found to induce prolonged diestrous in rats, which was followed by return to normal estrous cycling upon more prolonged exposure to continuous HG. Bromergocryptine was found to prevent this prolonged diestrous. In this study it is found that in female rats 20 h of 3.14 G exposure (D-1 1200 h until D-2 0800 h) can induce prolactin surge at D-2 1600 h. Shorter exposure time (8 h), or exposure during a different part of the estrous cycle (19 h: from D-1 0700 h until D-2 0200 h) could not elicit this prolactin surge. Similar exposure of male rats of HG did not alter significantly their prolactin levels. It is possible that the hypothalamus of male and female rats responds differently to stimulation by HG.

  15. Corona Discharge Influences Ozone Concentrations Near Rats

    SciTech Connect

    Goheen, Steven C.; Gaither, Kari A.; Anantatmula, Shantha M.; Mong, Gary M.; Sasser, Lyle B.; Lessor, Delbert L.

    2004-02-26

    Ozone is produced by corona discharge in air. Its production is enhanced near grounded water. Whether grounded animals behave like grounded water, producing more ozone was investigated. Rats were exposed to corona discharge in a plastic cage. The concentration of ozone in the gas phase was monitored. The ozone concentration exceeded ambient levels only in the presence of corona discharge and either rats or water. When water or rats were exposed to corona discharge, ozone levels were more than 10 times higher than controls. Ozone levels increased rapidly with applied voltage. There was also a correlation between the distance of the corona needle to the rats and the amount of ozone produced. As the distance increased, ozone production decreased. These results are discussed in relation to the potential exposure of mammals to ozone in the vicinity of corona discharge and electric fields.

  16. Phylogenetics of the laboratory rat Rattus norvegicus.

    PubMed

    Canzian, F

    1997-03-01

    A genealogic tree was constructed for inbred strains of the laboratory rat, including 63 strains and 214 of their substrains. Information on genetic and biochemical marker typings of these lines was collected from the literature and from the World Wide Web. Data on 995 polymorphisms were processed into a phylogenetic distance matrix, and a tree was obtained by the Fitch-Margoliash distance matrix method. The inbred strains of the laboratory rat showed an average polymorphism for pairwise comparison of 53%. Strain BN showed the highest genetic divergence from all the other ones. Comparison with the mouse phylogenetic tree indicated that laboratory rats possess a higher diversity than inbred strains of mice not derived from wild species. These results provide a phylogenetic basis in the choice of rat strains for genetic linkage experiments.

  17. Rat sperm motility analysis: methodologic considerations

    EPA Science Inventory

    The objective of these studies was to optimize conditions for computer-assisted sperm analysis (CASA) of rat epididymal spermatozoa. Methodologic issues addressed include sample collection technique, sampling region within the epididymis, type of diluent medium used, and sample c...

  18. Eating behavior reveals rats' preference for morphine.

    PubMed

    Yanaura, S; Suzuki, T; Kawai, T

    1980-04-01

    Using an automatic food intake measuring apparatus ("food intakometer"), we recorded the approach behavior to food, eating behavior and food intake of morphine dependent rats and examined the relationship among these factors and morphine dependence. Morphine dependent rats were produced by the drug-admixed food (DAF) method. In the choice trial of free feeding group, morphine dependent rats showed only the approach behavior both to drug-free diet and to morphine-admixed food, then ate the morphine-admixed food and approached the drug-free diet at the same period. Eating behavior in the case of morphine-admixed food was observed not only at night but also during thee feeding group, morphine dependent rats showed only the approach behavior both to drug-free diet and to morphine-admixed food, then ate the morphine-admixed food and approached the drug-free diet at the same period. Eating behavior in the case of morphine-admixed food was observed not only at night but also during the day time in the morphine dependent rats. In the choice trial of the limited feeding group, preference for morphine rapidly increased in every choice trial of each session and the preference rate became stable at about 60%. Eating patterns of these rats were similar to these in the free feeding group. When these rats were given morphine prior to the choice trial, eating behavior of those on the morphine-admixed food was inhibited dose-dependently, while eating behavior of these on the drug-free diet was enhanced dose-dependently. When these rats were allowed free access to drug-free diet for 1 hour previously to the choice trial, eating behavior of the rats on the morphine-admixed food in the choice trial was markedly enhanced. Thus, the rats clearly showed drug-seeking behavior and seemed to be able to distinguish between the need for morphine and satisfaction without it. Morphine dependent rats apparently can control their required maintenance dose.

  19. Methamphetamine enhances sexual behavior in female rats.

    PubMed

    Winland, Carissa; Haycox, Charles; Bolton, Jessica L; Jampana, Sumith; Oakley, Benjamin J; Ford, Brittany; Ornelas, Laura; Burbey, Alexandra; Marquette, Amber; Frohardt, Russell J; Guarraci, Fay A

    2011-06-01

    The present study evaluated the effects of methamphetamine (MA) on sexual behavior in female rats. In Experiment 1, ovariectomized, hormone-primed rats were injected with MA (1.0mg/kg, i.p.) or saline prior to a test for mate choice wherein females could mate with two males simultaneously. Female rats treated with saline returned to their preferred mate faster after receiving intromissions and visited their preferred mate at a higher rate than their non-preferred mate. In contrast, MA-treated female rats spent a similar amount of time with their preferred and non-preferred mate and failed to return to their preferred mate faster than to their non-preferred mate following intromissions. Two weeks later, the females received the same drug treatment but were tested for partner preference wherein females could spend time near a male or female stimulus rat. All subjects spent more time near the male stimulus than the female stimulus. However, the MA-treated rats visited the male stimulus more frequently and spent less time near the female stimulus than the saline-treated rats. Similar to Experiment 1, female rats in Experiment 2 were tested for mate choice and then two weeks later tested for partner preference; however, females received three daily injections of MA (1.0mg/kg, i.p.) or saline. Females treated chronically with MA returned to both males faster following intromissions than females treated with saline, independent of preference (i.e., preferred mate and non-preferred mate). Furthermore, MA-treated rats were more likely to leave either male (i.e., preferred or non-preferred mate) than saline-treated rats after receiving sexual stimulation. Although MA-treated subjects spent more time near the male stimulus than the female stimulus, they spent less time near either when compared to saline-treated subjects. The present results demonstrate that MA affects sexual behavior in female rats partly by increasing locomotion and partly by directly affecting sexual

  20. Anxiolytic Treatment Impairs Helping Behavior in Rats

    PubMed Central

    Ben-Ami Bartal, Inbal; Shan, Haozhe; Molasky, Nora M. R.; Murray, Teresa M.; Williams, Jasper Z.; Decety, Jean; Mason, Peggy

    2016-01-01

    Despite decades of research with humans, the biological mechanisms that motivate an individual to help others remain poorly understood. In order to investigate the roots of pro-sociality in mammals, we established the helping behavior test, a paradigm in which rats are faced with a conspecific trapped in a restrainer that can only be opened from the outside. Over the course of repeated test sessions, rats exposed to a trapped cagemate learn to open the door to the restrainer, thereby helping the trapped rat to escape (Ben-Ami Bartal et al., 2011). The discovery of this natural behavior provides a unique opportunity to probe the motivation of rodent helping behavior, leading to a deeper understanding of biological influences on human pro-sociality. To determine if an affective response motivates door-opening, rats receiving midazolam, a benzodiazepine anxiolytic, were tested in the helping behavior test. Midazolam-treated rats showed less helping behavior than saline-treated rats or rats receiving no injection. Yet, midazolam-treated rats opened a restrainer containing chocolate, highlighting the socially specific effects of the anxiolytic. To determine if midazolam interferes with helping through a sympatholytic effect, the peripherally restricted beta-adrenergic receptor antagonist nadolol was administered; nadolol did not interfere with helping. The corticosterone response of rats exposed to a trapped cagemate was measured and compared to the rats’ subsequent helping behavior. Rats with the greatest corticosterone responses showed the least helping behavior and those with the smallest responses showed the most consistent helping at the shortest latency. These results are discussed in terms of their implications for the interaction between stress and pro-social behavior. Finally, we observed that door-opening appeared to be reinforcing. A novel analytical tool was designed to interrogate the pattern of door-opening for signs that a rat’s behavior on one

  1. How rats combine temporal cues.

    PubMed

    Guilhardi, Paulo; Keen, Richard; MacInnis, Mika L M; Church, Russell M

    2005-05-31

    The procedures for classical and operant conditioning, and for many timing procedures, involve the delivery of reinforcers that may be related to the time of previous reinforcers and responses, and to the time of onsets and terminations of stimuli. The behavior resulting from such procedures can be described as bouts of responding that occur in some pattern at some rate. A packet theory of timing and conditioning is described that accounts for such behavior under a wide range of procedures. Applications include the food searching by rats in Skinner boxes under conditions of fixed and random reinforcement, brief and sustained stimuli, and several response-food contingencies. The approach is used to describe how multiple cues from reinforcers and stimuli combine to determine the rate and pattern of response bouts.

  2. Percutaneous nitroglycerin absorption in rats.

    PubMed

    Horhota, S T; Fung, H L

    1979-05-01

    Percutaneous nitroglycerin absorption was studied in shaved rats by monitoring unchanged plasma drug concentrations for up to 4 hr. Drug absorption from the neat liquid state or from an alcoholic solution was considerably poorer than that from a commercial ointment. This observation was unanticipated since the driving force for percutaneous drug absorption was assumed to be drug thermodynamics. Potential artifacts such as drug volatilization from the skin, reduction of surface area through droplet formation, and vehicle occlusion were investigated, but they did not appear to be responsible for the observed results. Two experimental aqueous nitroglycerin gels were prepared with polyethylene glycol 400. One gel contained just sufficient polyethylene glycol to solubilize the nitroglycerin; the other had excess polyethylene glycol to solubilize nitroglycerin far below saturation. Both gels gave extremely low plasma nitroglycerin levels. The composite data suggested that percutaneous nitroglycerin absorption is highly vehicle dependent and that this dependency cannot be explained by simple consideration of drug thermodynamic activity.

  3. Sleep Homeostasis in Infant Rats

    PubMed Central

    Blumberg, Mark S.; Middlemis-Brown, Jessica E.; Johnson, Eric D.

    2008-01-01

    Homeostatic regulation is a defining characteristic of sleep but has rarely been examined in infants. This study presents an automated method of sleep deprivation in which 5-day-old rats were shocked whenever the nuchal muscle became atonic. The intensity of shock was always set at the minimal level required to maintain arousal. Deprived pups exhibited rapid increases in sleep pressure, as evidenced by increased attempts to enter sleep and subsequent increases in sensory threshold; this increased sensory threshold was not due to sensory adaptation of peripheral receptors. In addition, myoclonic twitching was suppressed during the 30-min deprivation period, leading to rebound twitching during recovery sleep. These results provide the earliest demonstration of the homeostatic regulation of sleep in an altricial mammal. PMID:15598134

  4. Rat growth during chronic centrifugation

    NASA Technical Reports Server (NTRS)

    Pitts, G. C.; Oyama, J.

    1978-01-01

    Female weanling rats were chronically centrifuged at 4.15 G with controls at terrestrial gravity. Samples were sacrificed for body composition studies at 0, 28, 63, 105 and 308 days of centrifugation. The centrifuged group approached a significantly lower mature body mass than the controls (251 and 318g) but the rate of approach was the same in both groups. Retirement to 1G on the 60th day resulted in complete recovery. Among individual components muscle, bone, skin, CNS, heart, kidneys, body water and body fat were changed in the centrifuged group. However, an analysis of the growth of individual components relative to growth of the total fat-free compartment revealed that only skin (which increased in mass) was responding to centrifugation per se.

  5. Thyroid function in hemidecorticate rats.

    PubMed

    Munhoz, C O; Tosello, D O; Fernandez, G A; Merzel, J

    1988-01-01

    1. Thyroid function was evaluated in hemidecorticate (HD) and control (C) rats by determining serum T3 and T4 levels and the development of incisors and mandibles and through analysis of various histological features of the thyroid such as follicle size, colloid droplet content and [3H]-glycine uptake by follicular cells. 2. HD animals presented normal levels of circulating T3 but significantly lower T4 levels. 3. There was slight atrophy of the gland in HD animals and fewer colloid droplets were present in the cytoplasm of the follicular cells in this group, indicating a reduction in the breakdown of thyroglobulin. [3H]-glycine uptake by HD indicated that the rate of thyroglobulin biosynthesis was not altered in the experimental animals. 4. The growth of mandibles (weight) and incisors (weight and length) was reduced in HD compared to the control animals. 5. These results suggest that hemidecortication causes mild hypothyroidism (trophoprivic type) probably by affecting hypothalamic function.

  6. Quantity Discrimination in Domestic Rats, Rattus norvegicus

    PubMed Central

    Cox, Laura; Montrose, V. Tamara

    2016-01-01

    Simple Summary Quantity discrimination involves distinguishing which of two quantities is greater. This discrimination between larger and smaller quantities has only been demonstrated in rats post extensive training. We tested whether domestic rats could perform quantity discrimination without explicit training. We found that rats could distinguish the greater amount in comparisons of 1 vs. 2, 2 vs. 3, 3 vs. 5, 3 vs. 8, 4 vs. 6, and 4 vs. 8. Rats could not distinguish between 3 vs. 4, 4 vs. 5 and 5 vs. 6. We also found that as the ratio between quantities became finer the choice of the larger quantity decreased. We conclude that rats can perform quantity discrimination without extensive training and that their quantity discrimination ability is influenced by the ratio between quantities. Abstract Quantity discrimination is a basic form of numerical competence where an animal distinguishes which of two amounts is greater in size. Whilst quantity discrimination in rats has been investigated via training paradigms, rats’ natural quantity discrimination abilities without explicit training for a desired response have not been explored. This study investigated domestic rats’ ability to perform quantity discrimination. Domestic rats (n = 12) were examined for their ability to distinguish the larger amount under nine quantity comparisons. One-sample t-tests identified a significant preference for the larger quantity in comparisons of 1 vs. 2, 2 vs. 3, 3 vs. 5, 3 vs. 8, 4 vs. 6, and 4 vs. 8. No preference between quantities was found for comparisons of 3 vs. 4, 4 vs. 5 and 5 vs. 6. Overall, this study drew two key conclusions. Firstly, that domestic rats are capable of performing quantity discrimination without extensive training. Secondly, as subjects adhered to Weber’s law, it was concluded that the approximate number system underpins domestic rats’ ability to perform spontaneous quantity discrimination. PMID:27527223

  7. Can You Find the Rat Holes?

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Using its rock abrasion tool, otherwise known as 'Rat,' NASA's Mars Exploration Rover Opportunity dotted the slope of 'Endurance Crater' with dimples that give scientists a glimpse into its layered geologic history. This image from the rover's navigation camera, taken on sol 169 (July 15, 2004), highlights the prolific work of the robotic 'rodent.' How many Rat holes can you identify? You will be able to check your answer against an image to be posted soon with all the holes identified.

  8. Collagenous skeleton of the rat mystacial pad.

    PubMed

    Haidarliu, Sebastian; Simony, Erez; Golomb, David; Ahissar, Ehud

    2011-05-01

    Anatomical and functional integrity of the rat mystacial pad (MP) is dependent on the intrinsic organization of its extracellular matrix. By using collagen autofluorescence, in the rat MP, we revealed a collagenous skeleton that interconnects whisker follicles, corium, and deep collagen layers. We suggest that this skeleton supports MP tissues, mediates force transmission from muscles to whiskers, facilitates whisker retraction after protraction, and limits MP extensibility.

  9. A digital rat atlas of sectional anatomy

    NASA Astrophysics Data System (ADS)

    Yu, Li; Liu, Qian; Bai, Xueling; Liao, Yinping; Luo, Qingming; Gong, Hui

    2006-09-01

    This paper describes a digital rat alias of sectional anatomy made by milling. Two healthy Sprague-Dawley (SD) rat weighing 160-180 g were used for the generation of this atlas. The rats were depilated completely, then euthanized by Co II. One was via vascular perfusion, the other was directly frozen at -85 °C over 24 hour. After that, the frozen specimens were transferred into iron molds for embedding. A 3% gelatin solution colored blue was used to fill the molds and then frozen at -85 °C for one or two days. The frozen specimen-blocks were subsequently sectioned on the cryosection-milling machine in a plane oriented approximately transverse to the long axis of the body. The surface of specimen-blocks were imaged by a scanner and digitalized into 4,600 x2,580 x 24 bit array through a computer. Finally 9,475 sectional images (arterial vessel were not perfused) and 1,646 sectional images (arterial vessel were perfused) were captured, which made the volume of the digital atlas up to 369.35 Gbyte. This digital rat atlas is aimed at the whole rat and the rat arterial vessels are also presented. We have reconstructed this atlas. The information from the two-dimensional (2-D) images of serial sections and three-dimensional (3-D) surface model all shows that the digital rat atlas we constructed is high quality. This work lays the foundation for a deeper study of digital rat.

  10. Thermoregulation in hypergravity-acclimated rats

    NASA Technical Reports Server (NTRS)

    Monson, Conrad B.; Patterson, Susan L.; Horowitz, John M.; Oyama, Jiro

    1989-01-01

    The effect of acclimation to hypergravity on thermoregulatory responses of rats was determined by comparing data on core temperature, T(c), tail temperature, and O2 consumption in rats raised at 1 G (C) and at 2.1 G. It was found that, when C rats were exposed to an ambient temperature of 9 C concurrently with exposure to 2.1 G, the T(c) fell by about 6 C, while in rats acclimated to 2.1 G, the T(c) fell only by 1 C. Results of O2 consumption measurements showed that C rats exposed simultaneously to cold and hypergravity were not activating their thermogenic mechanism sufficiently to prevent a fall in T(c). In other experiments, rats acclimated to either 1 or 2.1 G were found to lack the ability to maintain their T(c) when exposed to a 5.8-G field or when cold-stressed at 1 G for extended times.

  11. Hematological Characteristics of the BB Wistar Rat.

    PubMed

    Wright, J R; Yates, A J; Shah, N T; Neff, J C; Covey, D W; Thibert, P

    1983-01-01

    Complete blood counts, differential white blood cell and platelet counts were performed on male and female BB Wistar diabetic rats (BBWd), their nondiabetic siblings (BBWnd) and outbred Wistar rats of the line from which the BB Wistar rats were derived. Most of the observed changes were strain-related (those present in both BBWd and BBWnd but not in control rats) rather than diabetes-related (those in BBWd but neither BBWnd nor control rats) and therefore probably due to the inbreeding process. The BBW strain had significantly lower numbers of white cells and platelets, as well as markedly changed differential white cell counts. Differential counts showed a pattern of lymphopenia, neutrophilia, monocytosis and eosinophilia. It is possible that these white blood cell changes contribute to the increased susceptibility to infection reported for the BBW strain. No significant difference in serum immunoglobulin concentrations was found in any of these three groups of rats. There- fore, hypogammaglobutinemia cannot account for the increased susceptibility to infections, but it is not possible to rule out an abnormality in the distribution of immunoglobulin fractions as an etiological factor. PMID:15311399

  12. Sham intake of ethanol in "P" rats.

    PubMed

    Rowland, N E; Morian, K R

    1994-01-01

    Alcohol-preferring (P) rats were surgically fitted with gastric fistulas, and intakes of 10% ethanol solution were measured in 1-h sessions either with the fistula closed (normal drinking) or open (sham drinking). In water-replete P rats in which ethanol access was limited to 1 h/day, no increase in intake was noted in the sham compared with normal drinking tests in the day. A small increase was seen when the sham drinking test was conducted at night. In water-deprived P rats, sham intake of ethanol was elevated over intakes in closed fistula trials. However, in comparison with water intake on separate test days, sham intake of ethanol by P rats was lower and satiated after 15-30 min. The absence of robust sham alcohol drinking in P rats is similar to what we have previously reported in normal Sprague-Dawley rats, suggesting that preabsorptive factors alone do not account for the strain differences in ethanol preference.

  13. Hypergravity suppresses bone resorption in ovariectomized rats

    NASA Astrophysics Data System (ADS)

    Ikawa, Tesshu; Kawaguchi, Amu; Okabe, Takahiro; Ninomiya, Tadashi; Nakamichi, Yuko; Nakamura, Midori; Uehara, Shunsuke; Nakamura, Hiroaki; Udagawa, Nobuyuki; Takahashi, Naoyuki; Nakamura, Hiroaki; Wakitani, Shigeyuki

    2011-04-01

    The effects of gravity on bone metabolism are unclear, and little has been reported about the effects of hypergravity on the mature skeleton. Since low gravity has been shown to decrease bone volume, we hypothesized that hypergravity increases bone volume. To clarify this hypothesis, adult female rats were ovariectomized and exposed to hypergravity (2.9G) using a centrifugation system. The rats were killed 28 days after the start of loading, and the distal femoral metaphysis of the rats was studied. Bone architecture was assessed by micro-computed tomography (micro-CT) and bone mineral density was measured using peripheral quantitative CT (pQCT). Hypergravity increased the trabecular bone volume of ovariectomized rats. Histomorphometric analyses revealed that hypergravity suppressed both bone formation and resorption and increased bone volume in ovariectomized rats. Further, the cell morphology, activity, proliferation, and differentiation of osteoclasts and osteoblasts exposed to hypergravity were evaluated in vitro. Hypergravity inhibited actin ring formation in mature osteoclasts, which suggested that the osteoclast activity was suppressed. However, hypergravity had no effect on osteoblasts. These results suggest that hypergravity can stimulate an increase in bone volume by suppressing bone resorption in ovariectomized rats.

  14. Colonic Fermentation Promotes Decompression sickness in Rats

    PubMed Central

    de Maistre, Sébastien; Vallée, Nicolas; Gempp, Emmanuel; Lambrechts, Kate; Louge, Pierre; Duchamp, Claude; Blatteau, Jean-Eric

    2016-01-01

    Massive bubble formation after diving can lead to decompression sickness (DCS). During dives with hydrogen as a diluent for oxygen, decreasing the body’s H2 burden by inoculating hydrogen-metabolizing microbes into the gut reduces the risk of DCS. So we set out to investigate if colonic fermentation leading to endogenous hydrogen production promotes DCS in fasting rats. Four hours before an experimental dive, 93 fasting rats were force-fed, half of them with mannitol and the other half with water. Exhaled hydrogen was measured before and after force-feeding. Following the hyperbaric exposure, we looked for signs of DCS. A higher incidence of DCS was found in rats force-fed with mannitol than in those force-fed with water (80%, [95%CI 56, 94] versus 40%, [95%CI 19, 64], p < 0.01). In rats force-fed with mannitol, metronidazole pretreatment reduced the incidence of DCS (33%, [95%CI 15, 57], p = 0.005) at the same time as it inhibited colonic fermentation (14 ± 35 ppm versus 118 ± 90 ppm, p = 0.0001). Pre-diveingestion of mannitol increased the incidence of DCS in fasting rats when colonic fermentation peaked during the decompression phase. More generally, colonic fermentation in rats on a normal diet could promote DCS through endogenous hydrogen production. PMID:26853722

  15. Chronic inhalation exposure of rats to nitromethane.

    PubMed

    Griffin, T B; Coulston, F; Stein, A A

    1996-07-01

    Male and female Long-Evans rats were housed in inhalation chambers and exposed to vapors of nitromethane (NM) at either 100 or 200 ppm. The animals were exposed 7 hr per day, 5 days per week for 2 years. Control groups of rats were also housed in a similar inhalation chamber, but NM was not introduced into the chamber. The animals were observed daily for signs of pharmacologic or toxicologic effect and body weights were recorded periodically. At the 2-year termination of the exposure period, clinical laboratory examinations (serum chemistry and hematology) were performed on selected animals and all surviving animals were sacrificed. All animals were necropsied and subjected to a thorough histopathologic examination. During the study there were no pharmacologic effects from exposure to NM at either 100 or 200 ppm. There was no effect on mortality on either sex at either exposure level. Body weights of male rats exposed to NM were not significantly different from those of control rats, but the body weights of female rats of both exposure groups were slightly less than their controls. There was no effect of exposure of rats of either sex to either level of NM on hematology. There were no clinically significant effects on serum chemistry. There were no effects of exposure to NM on organ weights. There were no significant differences in the nonneoplastic or neoplastic pathology related to exposure to NM. PMID:8812175

  16. Antiosteoporotic activity of icariin in ovariectomized rats.

    PubMed

    Nian, H; Ma, M-H; Nian, S-S; Xu, L-L

    2009-04-01

    Icariin was evaluated for its antiosteoporotic activity in an ovariectomized rat model of osteoporosis. The rats were divided into sham and OVX groups. The OVX rats were then subdivided into five groups treated with water, nylestriol (1 mg/kg body weight, weekly, orally) or icariin (ICA) (5, 25, and 125 mg/kg body weight, daily, orally) for 12 weeks. In OVX rats, the increases of body weight, serum BGP and ALP were significantly decreased by ICA treatment. In OVX rats, atrophy of uterus and descent of BMD were suppressed by treatment with ICA. In addition, ICA (125 mg/kg body weight) completely corrected the decreased serum concentration of Calcium, Phosphorus, and E(2) observed in OVX rats. ICA (125 mg/kg body weight) increased biomechanical strength significantly in comparison to the sham group. Histological results also showed its protective action through promotion of bone formation. The findings, assessed on the basis of biochemical, bone mineral density, biomechanical, and histopathological parameters, showed that ICA has a definite antiosteoporotic effect, similar to estrogen, especially effective for prevention bone fracture induced by estrogen deficiency. PMID:19269147

  17. Quantity Discrimination in Domestic Rats, Rattus norvegicus.

    PubMed

    Cox, Laura; Montrose, V Tamara

    2016-01-01

    Quantity discrimination is a basic form of numerical competence where an animal distinguishes which of two amounts is greater in size. Whilst quantity discrimination in rats has been investigated via training paradigms, rats' natural quantity discrimination abilities without explicit training for a desired response have not been explored. This study investigated domestic rats' ability to perform quantity discrimination. Domestic rats ( n = 12) were examined for their ability to distinguish the larger amount under nine quantity comparisons. One-sample t -tests identified a significant preference for the larger quantity in comparisons of 1 vs. 2, 2 vs. 3, 3 vs. 5, 3 vs. 8, 4 vs. 6, and 4 vs. 8. No preference between quantities was found for comparisons of 3 vs. 4, 4 vs. 5 and 5 vs. 6. Overall, this study drew two key conclusions. Firstly, that domestic rats are capable of performing quantity discrimination without extensive training. Secondly, as subjects adhered to Weber's law, it was concluded that the approximate number system underpins domestic rats' ability to perform spontaneous quantity discrimination. PMID:27527223

  18. Ontogeny of rat thymic dendritic cells.

    PubMed Central

    Vicente, A; Varas, A; Alonso, L; Gómez de Moral, M; Zapata, A G

    1994-01-01

    In the present study we have combined various in vivo and in vitro approaches to analyse the appearance and development throughout ontogeny and postnatal life of the dendritic cell (DC) populations of rat thymus. The in situ ultrastructural study demonstrated immature interdigitating cells (IDC)/DC in the thymus of 17-day-old embryonic rats, but thymic stromal cell cultures from 16-day-old fetal rats seemed to contain DC precursors which, after several days in culture, produced strongly class II major histocompatibility complex (MHC)-positive, mature DC. According to morphology and class II MHC expression we also defined three different DC populations in the late embryonic rat thymus; two of them, which remained in the adult rat thymus, could represent distinct developmental stages within the IDC/DC lineage. The third cell subset might be involved in a massive process of negative selection, presumably occurring at the end of fetal life in the rat thymus. In supporting the existence of thymic DC subpopulations, we also demonstrated a differential expression of various cell markers, including CD4, CD8, CD25, adhesion molecules and the antigen recognized by OX44 monoclonal antibody (mAb), on thymic DC during both embryonic and adult life. Their possible significance for the attributed functions to thymic DC are discussed extensively. Images Figure 1 Figures 3-5 Figures 6-9 PMID:7913915

  19. Hematological Characteristics of the BB Wistar Rat.

    PubMed

    Wright, J R; Yates, A J; Shah, N T; Neff, J C; Covey, D W; Thibert, P

    1983-01-01

    Complete blood counts, differential white blood cell and platelet counts were performed on male and female BB Wistar diabetic rats (BBWd), their nondiabetic siblings (BBWnd) and outbred Wistar rats of the line from which the BB Wistar rats were derived. Most of the observed changes were strain-related (those present in both BBWd and BBWnd but not in control rats) rather than diabetes-related (those in BBWd but neither BBWnd nor control rats) and therefore probably due to the inbreeding process. The BBW strain had significantly lower numbers of white cells and platelets, as well as markedly changed differential white cell counts. Differential counts showed a pattern of lymphopenia, neutrophilia, monocytosis and eosinophilia. It is possible that these white blood cell changes contribute to the increased susceptibility to infection reported for the BBW strain. No significant difference in serum immunoglobulin concentrations was found in any of these three groups of rats. There- fore, hypogammaglobutinemia cannot account for the increased susceptibility to infections, but it is not possible to rule out an abnormality in the distribution of immunoglobulin fractions as an etiological factor.

  20. Hypergravity modulates behavioral nociceptive responses in rats

    NASA Astrophysics Data System (ADS)

    Kumei, Y.; Shimokawa, R.; Toda, K.; Kawauchi, Y.; Makita, K.; Terasawa, M.; Ohya, K.; Shimokawa, H.

    Hypergravity (2G) exposure elevated the nociceptive threshold (pain suppression) concomitantly with evoked neuronal activity in the hypothalamus. Young Wistar male rats were exposed to 2G by centrifugal rotation for 10 min. Before and after 2G exposure, the nociceptive threshold was measured as the withdrawal reflex by using the von Frey type needle at a total of 8 sites of each rat (nose, four quarters, upper and lower back, tail), and then rats were sacrificed. Fos expression was examined immunohistochemically in the hypothalamic slices of the 2G-treated rats. When rats were exposed to 2G hypergravity, the nociceptive threshold was significantly elevated to approximately 150 to 250% of the 1G baseline control levels in all the examination sites. The 2G hypergravity remarkably induced Fos expression in the paraventricular and arcuate nuclei of the hypothalamus. The analgesic effects of 2G hypergravity were attenuated by naloxone pretreatment. Data indicate that hypergravity induces analgesic effects in rats, mediated through hypothalamic neuronal activity in the endogenous opioid system and hypothalamo-pituitary-adrenal axis.

  1. Colonic Fermentation Promotes Decompression sickness in Rats.

    PubMed

    de Maistre, Sébastien; Vallée, Nicolas; Gempp, Emmanuel; Lambrechts, Kate; Louge, Pierre; Duchamp, Claude; Blatteau, Jean-Eric

    2016-01-01

    Massive bubble formation after diving can lead to decompression sickness (DCS). During dives with hydrogen as a diluent for oxygen, decreasing the body's H2 burden by inoculating hydrogen-metabolizing microbes into the gut reduces the risk of DCS. So we set out to investigate if colonic fermentation leading to endogenous hydrogen production promotes DCS in fasting rats. Four hours before an experimental dive, 93 fasting rats were force-fed, half of them with mannitol and the other half with water. Exhaled hydrogen was measured before and after force-feeding. Following the hyperbaric exposure, we looked for signs of DCS. A higher incidence of DCS was found in rats force-fed with mannitol than in those force-fed with water (80%, [95%CI 56, 94] versus 40%, [95%CI 19, 64], p < 0.01). In rats force-fed with mannitol, metronidazole pretreatment reduced the incidence of DCS (33%, [95%CI 15, 57], p = 0.005) at the same time as it inhibited colonic fermentation (14 ± 35 ppm versus 118 ± 90 ppm, p = 0.0001). Pre-diveingestion of mannitol increased the incidence of DCS in fasting rats when colonic fermentation peaked during the decompression phase. More generally, colonic fermentation in rats on a normal diet could promote DCS through endogenous hydrogen production.

  2. Transient dehydration of lungs in tail-suspended rats

    NASA Technical Reports Server (NTRS)

    Hargens, A. R.; Steskal, J.; Morey-Holton, E. R.

    1985-01-01

    The fluid balance in the lungs of rats exposed to head-down tilt is examined. Six Munich-Wister rats were suspended for 7 days and 10 Sprague-Dawley rats for 14 days using the technique of Morey (1979). The water contents of the lungs of the suspended and a control group are calculated and compared. The data reveal that the two-days suspended rats had dehydrated lungs; however, the lungs of the 14-day suspended and control group rats were similar. It is noted that the dehydration in the 2-day suspended rats is caused by general dehydration not the head-tilt position.

  3. Genetic influence on brain catecholamines: high brain norepinephrine in salt-sensitive rats

    SciTech Connect

    Iwai, J; Friedman, R; Tassinari, L

    1980-01-01

    Rats genetically sensitive to salt-induced hypertension evinced higher levels of plasma norepinephrine and epinephrine than rats genetically resistant to hypertension. The hypertension-sensitive rats showed higher hypothalamic norepinephrine and lower epinephrine than resistant rats. In response to a high salt diet, brain stem norepinephrine increased in sensitive rats while resistant rats exhibited a decrease on the same diet.

  4. Intermittent heat exposure and thirst in rats.

    PubMed

    Barney, Christopher C; Kuhrt, David M

    2016-04-01

    Adequate water intake, supporting both cardiovascular function and evaporative cooling, is a critical factor in mitigating the effects of heat waves, which are expected to increase with global warming. However, the regulation of water intake during periods of intermittent heat exposure is not well understood. In this study, the effects of access to water or no access during intermittent heat exposure were assessed using male Sprague-Dawley rats exposed to 37.5°C for 4 h/day. After 7 days of intermittent heat exposure, reductions in evaporative water loss were observed in all animals and reductions in water intake following heat exposure occurred as the days of heat exposure increased. Rats that were not allowed water during the 7 days of exposure had decreased rehydration levels, however, rats allowed access to water increased water intake during exposure and exhibited higher overall rehydration levels over the same time period. Peripheral administration of angiotensinII, mimicking activation of volemic thirst, or hypertonic saline solution, activating intracellular thirst, did not result in alteration of water intake in rats exposed to heat with access to water compared to control rats. In contrast, rats exposed to heat without access to water had reduced water intake after administration of hypertonic saline and increased water intake after administration of angiotensinIIcompared to control rats. These experiments demonstrate that thirst responses to intermittent heat exposure are altered by providing water during heat exposure and that intermittent heat exposure without access to water alters drinking responses to both intracellular and extracellular thirst challenges.

  5. Renal function in single-kidney rats.

    PubMed

    Provoost, A P; De Keijzer, M H; Wessel, J N; Molenaar, J C

    1989-01-01

    Can a single kidney survive for a normal life span? This is the type of question frequently asked by patients and especially by parents of children who lose one kidney in early childhood. Based on our wide experience with single-kidney rats, we will try to give an answer to this question. After the removal of its counterpart, the single remaining kidney will rapidly adapt to the new situation by a compensatory increase in the glomerular filtration rate (GFR) and renal mass. This is true not only for intact kidneys but also for damaged ones. The GFR level obtained by damaged kidneys will be less than that of intact single kidneys, however, depending on the degree of initial damage. The GFR is stable for a certain period of time, which is longer for intact single kidneys than for damaged kidneys and also depends on the daily protein intake; after that renal function will deteriorate. This decline in GFR is preceded by a marked increase in urinary protein excretion. Although the follow-up period is not completed yet, the survival time of single intact kidneys in rats on a normal diet is expected to be 15%-20% less than the normal rat life span. In rats on a lifelong high protein intake the kidney survival time drops to 40% below the normal rat life span. In rats on a moderately reduced protein intake, however, single intact kidneys may survive for a normal life span. The situation is worse for single damaged kidneys. Depending on the severity of the initial damage, kidney survival time will be much less than a normal life span. We studied rats with an initial recovery to 75% of renal function. Despite this initial recovery, the animals died of renal failure within 50% of the expected life span. A low-protein diet prolonged the renal survival by about 12%, a high-protein diet shortened it by the same percentage.

  6. Calcium-deprived rats avoid sweet compounds.

    PubMed

    Tordoff, M G; Rabusa, S H

    1998-07-01

    To characterize the link between calcium status and sweet solution intake, rats fed a diet containing 25 mmol Ca2+/kg (Ca-25, low calcium) or 150 mmol Ca2+/kg (Ca-150, control) were given 48-h two-bottle tests with a choice between water and various concentrations of a nutrient (sucrose, Polycose, ethanol and/or corn oil). Rats fed the Ca-25 diet had significantly lower sucrose intakes and preferences over the entire range tested (10-320 g/L) even though the same (Experiment 1), or identically treated (Experiment 2a) rats had normal Polycose and ethanol intakes and normal (Experiment 1, 2b) or significantly greater (Experiment 2a) corn oil intakes. In additional tests, rats fed the Ca-25 diet had significantly lower intakes relative to rats fed the Ca-150 diet of other sweeteners (30 mmol/L D-phenylalanine, 1 mmol/L saccharin and 0.3 mmol/L aspartame), significantly higher intakes of 0.5 mg/L capsaicin and 300 mmol/L monosodium glutamate, and normal intakes of 10 g/L or 80 g/L safflower oil and 10 g/L peanut oil. In a three-cup macronutrient selection experiment (Experiment 3), calcium-deprived rats ate significantly less of a high sucrose carbohydrate source and significantly more of a protein source than did controls. These results suggest that calcium deficiency reduces the rat's liking for sweetness, irrespective of the type or form of sweetener, and that this is not due to a general reduction in energy intake.

  7. [Pituitary function of dysgenesic femal rats. Studies with grafting method].

    PubMed

    Vanhems, E; Busquet, J

    1975-01-01

    Misulban administered to pregnant rats on the 15th day of gestation provoked gonadal dysgenesia in the offspring. Study of the pituitary function of dysgenesic female rats, realized by grafting method, showed gonadotrophic hypersecretion.

  8. Effect of simulated weightlessness on energy metabolism in the rat

    NASA Technical Reports Server (NTRS)

    Jordan, J. P.; Sykes, H. A.; Crownover, J. C.; Schatte, C. L.; Simmons, J. B., II; Jordan, D. P.

    1982-01-01

    Results of measurements of food uptake and body weight changes occurring in rats suspended from a harness so that the antigravity muscles were not used for locomotion are presented. The rats were tested in pairs, with both in a harness but only one suspended off its hind legs; this section lasted 7 days. A second phase of the experiment involved feeding the nonsuspended rat the same amount of food the experimental rat had consumed the previous day. All rats experienced decreased in body weight and food intake in the first stage, while in the second stage the suspended rat lost more weight. The total oxygen uptake, CO2 output, and rate of C-14O2 production were depressed in the suspended rats, then returned to normal levels once the rats were back on the ground. It is concluded that the gross metabolic processes are unaffected by simulated weightlessness.

  9. High prevalence of rat hepatitis E virus in wild rats in China.

    PubMed

    Li, Wei; Guan, Dawei; Su, Juan; Takeda, Naokazu; Wakita, Takaji; Li, Tian-Cheng; Ke, Chang Wen

    2013-08-30

    Serum samples from a total of 713 wild rats captured in Zhanjiang city in China from December 2011 to September 2012 were investigated for the prevalence of rat hepatitis E virus (HEV) by exploring rat HEV-specific antibodies and RNA. By an ELISA based on recombinant rat HEV-like particles (HEV-LPs), 23.3% (166/713) of the rats were positive for anti-HEV IgG, and 8.3% (59/713) were positive for anti-HEV IgM. The IgG-positive rates in Rattus norvegicus, Bandicota indica, Rattus flavipectus, Rattus rattoides losea, and Rattus rattus hainanus, were 27.8% (64/230), 23.0% (40/174), 19.9% (34/171), 21.5% (26/121), and 11.8% (2/17), while the IgM-positive rates were 8.3% (19/230), 6.9% (12/174), 8.2% (14/171), 10.7% (13/121), and 5.9% (1/17), respectively. The IgG-positive rate of the rats captured in rural areas, 24.1% (84/348), was higher than that in the central area of Zhanjiang city, 15.1% (32/212). The highest IgG-positive rates, as high as 45.3% (39/86), were detected in wild rats trapped in the garbage dump. Twelve of the 59 IgM-positive serum samples were positive for HEV RNA, which was detected in all of the wild rat species except R. rattus hainanus. A phylogenetic analysis of the partial genome of rat HEV ORF1 indicated that all of the 12 HEV strains belong to rat HEV, and no other genotype HEV were detected. The rat HEV from Zhangjiang city could be classified into three separated clusters, suggesting that the infection due to rat HEV with a variety of genome entities occurs extensively among wild rats in China.

  10. Urea synthesis in rats fed diet containing kidney beans.

    PubMed

    Scislowski, P W; Grant, G; Harris, I; Pickard, K; Pusztai, A

    1992-10-01

    When rats were fed a diet containing kidney bean (Phaesolus vulgaris) urea excretion was increased 3-5 fold. Isolated liver mitochondria from rats fed the kidney bean diet produced 40% more citrulline in the presence of arginine than mitochondria isolated from control rats. Mitochondrial activities of urea cycle enzymes and N-acetylglutamate synthetase were similar in animals fed diets containing kidney bean or lactalbumin. The possible mechanisms causing acute urea production in rats fed with kidney bean are discussed.

  11. Urea synthesis in rats fed diet containing kidney beans.

    PubMed

    Scislowski, P W; Grant, G; Harris, I; Pickard, K; Pusztai, A

    1992-10-01

    When rats were fed a diet containing kidney bean (Phaesolus vulgaris) urea excretion was increased 3-5 fold. Isolated liver mitochondria from rats fed the kidney bean diet produced 40% more citrulline in the presence of arginine than mitochondria isolated from control rats. Mitochondrial activities of urea cycle enzymes and N-acetylglutamate synthetase were similar in animals fed diets containing kidney bean or lactalbumin. The possible mechanisms causing acute urea production in rats fed with kidney bean are discussed. PMID:1445392

  12. An experimental task to examine the mirror system in rats

    PubMed Central

    Takano, Yuji; Ukezono, Masatoshi

    2014-01-01

    The mirror system in the brain is considered to be a neural basis of sociality, but previous studies have been limited to primates. Here we report an experimental task to examine the mirror system in rats. We show that a rat could reach to a pellet and grasp and eat it in front of another rat that was observing the reaching, which indicates that the task will enable us to start exploring the rat mirror system. PMID:25323637

  13. Social influences on morphine sensitization in adolescent rats.

    PubMed

    Hofford, Rebecca S; Schul, Destri L; Wellman, Paul J; Eitan, Shoshana

    2012-05-01

    Given that social influences are among the strongest predictors of adolescents' drug use, this study examines the effects of social interactions on morphine sensitization in both adolescent and adult rats. Rats treated with morphine (twice daily, 6 days, 2.5-10 mg/kg, subcutaneously, s.c.) or saline were group-housed in two different conditions. Thus, four experimental groups were examined for each age group: (1) morphine-treated rats housed physically and visually separate from saline-injected rats ('morphine only'); (2) morphine-treated rats housed together with saline-injected rats ('morphine cage-mates'); (3) saline-injected rats housed together with morphine-treated rats ('saline cage-mates'); and (4) saline-injected rats housed physically and visually separate from morphine-treated rats ('saline only'). Starting 9 days following the last morphine injection, rats were individually examined once daily for 5 consecutive days for their locomotor response to 2.5 mg/kg of morphine. For both age groups, there were no significant differences in morphine-induced hyper-locomotion between saline cage-mates and saline only rats. Morphine only rats exhibited morphine locomotor sensitization as compared to both the saline only and saline cage-mates rats. Notably, a significant difference was observed between the adolescent morphine cage-mates and morphine only rats. The adolescent morphine cage-mates did not exhibit the enhanced locomotor response as compared to the saline only and saline cage-mate rats. A trend of reduced morphine locomotor sensitization was observed in the adult morphine cage-mates as compared to morphine only but it did not reach statistical significance. Thus, this study demonstrates social influences on morphine sensitization which are more prevalent in adolescents as compared to adults.

  14. An experimental task to examine the mirror system in rats.

    PubMed

    Takano, Yuji; Ukezono, Masatoshi

    2014-01-01

    The mirror system in the brain is considered to be a neural basis of sociality, but previous studies have been limited to primates. Here we report an experimental task to examine the mirror system in rats. We show that a rat could reach to a pellet and grasp and eat it in front of another rat that was observing the reaching, which indicates that the task will enable us to start exploring the rat mirror system. PMID:25323637

  15. Nigella Sativa reverses osteoporosis in ovariectomized rats

    PubMed Central

    2014-01-01

    Background Osteoporosis poses a significant public health issue. It is a skeletal disorder characterized by compromised bone strength that predisposes to increased risk of fracture. There is a direct relationship between the lack of estrogen after menopause and the development of osteoporosis. About 33% of women over 50 will experience bone fractures as a result of osteoporosis. Nigella Sativa (NS) has been shown to have beneficial effects on bone and joint diseases. The present study was conducted to elucidate the protective effect of Nigella Sativa on osteoporosis produced by ovariectomy in rats. Methods Female Wistar rats aged 12–14 months were divided into three groups: sham-operated control (SHAM), ovariectomized (OVX), and ovariectomized supplemented with nigella sativa (OVX-NS) orally for 12 weeks; 4 weeks before ovariectomy and 8 weeks after. After 12 weeks, plasma levels of calcium (Ca+2), phosphorous (Pi), alkaline phosphatase (ALP), amino terminal collagen type 1 telopeptide, malondialdehyde (MDA), nitrates, nitric oxide surrogate, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) were measured. Histological examination of the liver and the tibia was conducted. Histomorphometric analysis of the tibia was also performed. Results OVX rats showed significant decrease in plasma Ca+2, accompanied by a significant increase in plasma ALP, amino terminal collagen type 1 telopeptide, MDA, nitrates, TNF-α and IL-6. These changes were reversed by NS supplementation in OVX-NS group to be near SHAM levels. Histological examination of the tibias revealed discontinuous eroded bone trabeculae with widened bone marrow spaces in OVX rats accompanied by a significant decrease in both cortical and trabecular bone thickness compared to Sham rats. These parameters were markedly reversed in OVX-NS rats. Histological examination of the liver showed mononuclear cellular infiltration and congestion of blood vessels at the portal area in OVX rats which were not found

  16. Pharmacokinetics of memantine in rats and mice.

    PubMed

    Beconi, Maria G; Howland, David; Park, Larry; Lyons, Kathryn; Giuliano, Joseph; Dominguez, Celia; Munoz-Sanjuan, Ignacio; Pacifici, Robert

    2011-12-15

    To evaluate the potential of memantine as a therapeutic agent for Huntington's disease (HD) we have undertaken a series of in vitro, ex vivo and whole animal studies to characterize its pharmacokinetics (PK) and pharmacodynamics (PD) in rats and mice. Results from these studies will enable determination of memantine exposures needed to engage the related functional PD marker and help predict the dose regimen for clinical trials to test its proposed mechanism of action; the selective blockade of extrasynaptic, but not synaptic, NMDA receptors. The studies reported here describe the PK of memantine in rats and mice at low (1 mg/kg) and high (10 mg/kg) doses. Our studies indicate that the clearance mechanisms of memantine in rats and mice are different from those in human, and that clearance needs to be taken into account when extrapolating to the human. In rats only, there is a significant metabolic contribution to memantine clearance at lower dose levels. While memantine is primarily cleared renally in all three species, the proportion of total systemic clearance above the glomerular filtration rate (GFR) is much higher in rats and mice (~13, 4.5, and 1.4 times higher than GFR in rats, mice, and humans, respectively), suggesting that the contribution of active transport to memantine elimination in rats and mice is more significant than in the human. In rats and mice, memantine had a short half-life (<4 h) and steep Cmax/Cmin ratios (>100). In the human, the half-life of memantine was reported to be very long (60-80 h) with a Cmax/Cmin ratio at steady state concentrations of ~1.5. A small change in the clearance of memantine - for example due to renal impairment or competition for the elimination pathway with a co-administered drug - will likely affect exposure and, therefore, the selectivity of memantine on NMDA receptors . The PK differences observed between these species demonstrate that the PK in mice and rats cannot be directly extrapolated to the human. Further

  17. Relaxin and drinking in pregnant rats.

    PubMed

    Hornsby, D J; Wilson, B C; Summerlee, A J

    2001-01-01

    Work reported in this chapter describes the potential role of relaxin in resetting cardiovascular thresholds in pregnant rats. Relaxin, a polypeptide produced primarily by the ovary in pregnant animals in many species, is also produced in the brain. Exogenous administration of relaxin into the brain causes a profound drinking response which is negated by pretreatment with a specific monoclonal antibody to rat relaxin when the antibody is injected into the brain. Neutralizing the action of endogenous brain relaxin in pregnant rats also blocks the normal increase in drinking that is observed in rats at night during the second half of pregnancy. Relaxin acts through the forebrain angiotensin system at the level of the subfornical organ (an important interface between the blood, the brain and the cerebrospinal fluid) as blockade of the angiotensin II receptor action negates several central actions of relaxin. Expression of angiotensin II AT1 receptors in the subfornical organ increases in parallel with the increase in circulating relaxin seen in the second half of pregnancy. Neutralizing the effects of endogenous brain relaxin, using central injections of the monoclonal antibody, blocks this increase in the expression of angiotensin II AT1 receptors in subfornical organ. These data imply that relaxin in the brain may act to affect central cardiovascular thresholds in rats and this may be important for the normal physiology of pregnancy.

  18. A rat model for hepatitis E virus

    PubMed Central

    Mishra, Niraj; Verbeken, Erik; Ramaekers, Kaat; Dallmeier, Kai

    2016-01-01

    ABSTRACT Hepatitis E virus (HEV) is one of the prime causes of acute viral hepatitis, and chronic hepatitis E is increasingly recognized as an important problem in the transplant setting. Nevertheless, the fundamental understanding of the biology of HEV replication is limited and there are few therapeutic options. The development of such therapies is partially hindered by the lack of a robust and convenient animal model. We propose the infection of athymic nude rats with the rat HEV strain LA-B350 as such a model. A cDNA clone, pLA-B350, was constructed and the infectivity of its capped RNA transcripts was confirmed in vitro and in vivo. Furthermore, a subgenomic replicon, pLA-B350/luc, was constructed and validated for in vitro antiviral studies. Interestingly, rat HEV proved to be less sensitive to the antiviral activity of α-interferon, ribavirin and mycophenolic acid than genotype 3 HEV (a strain that infects humans). As a proof-of-concept, part of the C-terminal polymerase sequence of pLA-B350/luc was swapped with its genotype 3 HEV counterpart: the resulting chimeric replicon replicated with comparable efficiency as the wild-type construct, confirming that LA-B350 strain is amenable to humanization (replacement of certain sequences or motifs by their counterparts from human HEV strains). Finally, ribavirin effectively inhibited LA-B350 replication in athymic nude rats, confirming the suitability of the rat model for antiviral studies. PMID:27483350

  19. Cardiopulmonary Changes with Moderate Decompression in Rats

    NASA Technical Reports Server (NTRS)

    Robinson, R.; Little, T.; Doursout, M.-F.; Butler, B. D.; Chelly, J. E.

    1996-01-01

    Sprague-Dawley rats were compressed to 616 kPa for 120 min then decompressed at 38 kPa/min to assess the cardiovascular and pulmonary responses to moderate decompression stress. In one series of experiments the rats were chronically instrumented with Doppler ultrasonic probes for simultaneous measurement of blood pressure, cardiac output, heart rate, left and right ventricular wall thickening fraction, and venous bubble detection. Data were collected at base-line, throughout the compression/decompression protocol, and for 120 min post decompression. In a second series of experiments the pulmonary responses to the decompression protocol were evaluated in non-instrumented rats. Analyses included blood gases, pleural and bronchoalveolar lavage (BAL) protein and hemoglobin concentration, pulmonary edema, BAL and lung tissue phospholipids, lung compliance, and cell counts. Venous bubbles were directly observed in 90% of the rats where immediate post-decompression autopsy was performed and in 37% using implanted Doppler monitors. Cardiac output, stroke volume, and right ventricular wall thickening fractions were significantly decreased post decompression, whereas systemic vascular resistance was increased suggesting a decrease in venous return. BAL Hb and total protein levels were increased 0 and 60 min post decompression, pleural and plasma levels were unchanged. BAL white blood cells and neutrophil percentages were increased 0 and 60 min post decompression and pulmonary edema was detected. Venous bubbles produced with moderate decompression profiles give detectable cardiovascular and pulmonary responses in the rat.

  20. Radioimmunoimaging of pneumocystis carinii infection in rats

    SciTech Connect

    Vallabhajosula, S.; Shane, L.B.; Goldsmith, S.J.; Lipszyc, H.; Walzer, P.

    1984-01-01

    Pneumocystis carinil pneumonia (PCP) is seen in patients with impaired immunity due to chemotherapeutic suppression or to a primary disorder, congenital or AIDS. Although radiogallium imaging has been helpful in the workup of PCP, it is non-specific. Since there is no early specific non-invasive method to diagnose PCP, the authors are developing an imaging technique using radiolabeled antibodies. Fulminant PCP was induced in rats by injecting cortisone, 20mg 2-3 times/wk for 8 wks. PC cells isolated from rat lung were injected into rabbits. The antiserum thus derived was separated and purified using Protein-A bound sepharose column with identification of IgG by polyacrylamide gel electrophoresis. Both rabbit antipneumocystis antibodies and purified IgG(Sigma) were iodinated with I-131 to a high specific activity (3-5..mu..Ci/ug) using a lactoperoxidase method. /sup 131/I-labeled specific and non-specific IgG were injected into rats with PC infection and imaged with an Anger camera. After sacrifice, I-131 activity/gram tissue (lung, liver, heart) was determined and expressed as organ ratios. An increased uptake of specific antibody in lungs of rats with PCP was demonstrated by organ counting and imaging. This increase was not seen in normal controls or rats injected with non-specific IgG. These data provide a basis for radioimmunoimaging of infectious diseases.

  1. Glutathione system in young spontaneously hypertensive rats.

    PubMed

    Lee, S K; Arunkumar, Sundaram; Sirajudeen, K N S; Singh, H J

    2010-12-01

    Glutathione (GSH) forms a part of the antioxidant system that plays a vital role in preventing oxidative stress, and an imbalance in the oxidant/antioxidant system has been linked to the pathogenesis of hypertension. The aim of this study was to investigate the status of the GSH system in the kidney of spontaneously hypertensive rats (SHR). Components of the GSH system, including glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST), and total GSH content, were measured in the kidneys of 4, 6, 8, 12, and 16 weeks old SHR and Wistar-Kyoto (WKY) rats. Systolic blood pressure of SHR was significantly higher from the age of 6 weeks onwards compared with age-matched WKY rats. GPx activity in the SHR was significantly lower from the age of 8 weeks onwards when compared to that in age-matched WKY rats. No significant differences were evident in the GPx-1 protein abundance, and its relative mRNA levels, GR, GST activity, and total GSH content between SHR and age-matched WKY rats. The lower GPx activity suggests of an impairment of the GSH system in the SHR, which might be due to an abnormality in its protein rather than non-availability of a cofactor. Its role in the development of hypertension in SHR however remains unclear.

  2. Ultrasonic evoked responses in rat cochlear nucleus

    PubMed Central

    Du, Yi; Ping, Junli; Li, Nanxin; Wu, Xihong; Li, Liang; Galbraith, Gary

    2009-01-01

    Numerous studies have reported auditory brainstem responses evoked by stimuli within the “normal” hearing range of rats, with maximum sensitivity peaking around 16 kHz. Yet rats also emit and respond to sounds in the ultrasonic (US) frequency range (30-100 kHz). However very few electrophysiological studies have recorded auditory brainstem responses using US stimuli, and none have exceeded 70 kHz. We report here short-latency (1-3 ms) evoked potentials recorded in rat cochlear nucleus (CN) to US stimuli ranging from 40-90 kHz. Robust responses were recorded in 33 of 36 CN recording sites to stimuli ranging from 40-60 kHz; and twenty-eight of these sites continued to yield well defined responses out to 90 kHz. Latencies systematically increased and overall amplitudes decreased with increasing US frequency. Amplitudes differed significantly in the three CN subnuclei, being largest in posterior-ventral (PVCN) and smallest in anterior-ventral (AVCN). The fact that well defined responses can be recorded to stimuli as high as 90 kHz significantly extends the recorded upper frequency range of neural activity in the brainstem auditory pathway of the rat. These evoked potential results agree with the well documented behavioral repertoire of rats in the US frequency range. PMID:17803975

  3. Purification and sequence of rat oxyntomodulin.

    PubMed Central

    Collie, N L; Walsh, J H; Wong, H C; Shively, J E; Davis, M T; Lee, T D; Reeve, J R

    1994-01-01

    Structural information about rat enteroglucagon, intestinal peptides containing the pancreatic glucagon sequence, has been based previously on cDNA, immunologic, and chromatographic data. Our interests in testing the physiological actions of synthetic enteroglucagon peptides in rats required that we identify precisely the forms present in vivo. From knowledge of the proglucagon gene sequence, we synthesized an enteroglucagon C-terminal octapeptide common to both proposed enteroglucagon forms, glicentin and oxyntomodulin, but sharing no sequence overlap with glucagon. We then developed a radioimmunoassay using antibodies raised against the octapeptide that was specific for enteroglucagon peptides without cross-reacting with glucagon. Rat intestine was extracted, and one presumptive enteroglucagon form was purified by following the enteroglucagon C-terminal octapeptide-like immunoreactivity through several HPLC purification steps. Structural characterization of the material by amino acid composition, microsequence, and mass spectral analyses identified the peptide as rat oxyntomodulin. The 37-residue peptide consists of pancreatic glucagon plus the C-terminal extension, Lys-Arg-Asn-Arg-Asn-Asn-Ile-Ala. This now permits synthesis of an unambiguous duplicate of endogenous rat oxyntomodulin for physiological studies. Images PMID:7937770

  4. Opiates and cerebral functional activity in rats

    SciTech Connect

    Trusk, T.C.

    1986-01-01

    Cerebral activity was measured using the free-fatty acid (1-/sup 14/C) octanoate as a fast functional tracer in conscious, unrestrained rats 5 minutes after intravenous injection of heroin, cocaine or saline vehicle. Regional changes of octanoate labeling density in the autoradiograms relative to saline-injected animals were used to determine the functional activity effects of each drug. Heroin and cocaine each produced a distinctive pattern of activity increases and suppression throughout the rat brain. Similar regional changes induced by both drugs were found in limbic brain regions implicated in drug reinforcement. Labeled octanoate autoradiography was used to measure the cerebral functional response to a tone that had previously been paired to heroin injections. Rats were trained in groups of three consisting of one heroin self-administration animal, and two animals receiving yoked infusion of heroin or saline. A tone was paired with each infusion during training. Behavioral experiments in similarly trained rats demonstrated that these training conditions impart secondary reinforcing properties to the tone in animals previously self-administering heroin, while the tone remains behaviorally neutral in yoked-infusion rats. Cerebral functional activity was measured during presentation of the tone without drug infusion. Octanoate labeling density changed in fifteen brain areas in response to the tone previously paired to heroin without response contingency. Labeling density was significantly modified in sixteen regions as a result of previously pairing the tone to response-contingent heroin infusions.

  5. Beacon immunoreactivity in the rat hypothalamus.

    PubMed

    Ng, Y K; Brailoiu, G C; Dun, S L; Ling, E A; Yang, J; Chang, J K; Dun, N J

    2006-05-01

    Beacon (BC) is a peptide of 73 amino acids, whose gene expression was first reported in the hypothalamus of Psammomys obesus (or Israeli sand rat). To appreciate better the functional role of BC in normal rats and sand rats, the distribution of BC immunoreactivity (irBC) and its subcellular localization were studied in the brain of Sprague-Dawley rats. In the hypothalamus, intense staining was present in neurons of the supraoptic (SO), paraventricular (PVH), and accessory neurosecretory nuclei and in cell processes of median eminence. Double labeling of the hypothalamic sections with mouse monoclonal oxytocin (OT) antibody and rabbit polyclonal BC antiserum revealed that nearly all OT-immunoreactive cells from SO, PVH, and accessory neurosecretory nuclei were irBC. Double labeling of the sections with guinea pig vasopressin (VP) antiserum and BC antiserum showed that a population of VP-immunoreactive neurons was irBC. By immunoelectron microscopy, immunoreactive product was associated with mitochondrial membranes or appeared as electron-dense bodies in many PVH and SO neurons. Most of the neurosecretory granules were unstained for BC. Taken together, our results indicate the presence of beacon in the OT-containing neurons and a population of VP-containing neurons, mostly associated with mitochondrial membrane. Insofar as the amino acids sequence of beacon is identical to that of ubiquitin-like 5, it is possible that the distribution of BC immunoreactivity noted in our study is that of ubiquitin-like 5 peptide in the rat hypothalamus.

  6. Immunopathological features of rat Staphylococcus aureus arthritis.

    PubMed Central

    Bremell, T; Lange, S; Holmdahl, R; Rydén, C; Hansson, G K; Tarkowski, A

    1994-01-01

    Staphylococcus aureus is the most common bacterial species found in nongonococcal bacterial arthritis in humans. We present the first description, to our knowledge, of an outbreak of spontaneous staphylococcal arthritis in a rat colony. In a group of 10 rats, 9 displayed arthritis. Clinically, the most obvious findings were arthritis of one or both hindpaws and malaise. Bacteriophage typing showed the common phage type 85 in isolates recovered from the joints, blood, and bedding of rats and from the nose and cheeks of one person from the staff of the animal facility. The S. aureus strain proved to produce staphylococcal enterotoxin A and exhibited strong binding to collagen types I and II and bone sialoprotein, which are potentially important virulence factors. When the recovered S. aureus strain was injected intravenously into healthy rats, severe septic arthritis was induced in almost all of the animals. The arthritic lesions were characterized by infiltration of phagocytic cells and T lymphocytes into the synovium. Many of the synovial cells strongly expressed major histocompatibility complex class II molecules. Increased levels of interleukin 6 in serum as well as a prominent polyclonal B-cell activation were noted throughout the disease course. Pretreatment of S. aureus-injected rats in vivo with an antibody to the alpha beta T-cell receptor significantly decreased the severity of the arthritis. Our results indicate that alpha beta + T lymphocytes contribute to an erosive and persistent course of S. aureus arthritis. Images PMID:8188356

  7. Plasma cholesterol transport in anhepatic rats.

    PubMed Central

    Quarfordt, S H; Landis, B; Cucchiaro, G; Yamaguchi, Y; Oswald, B

    1992-01-01

    The plasma appearance of newly synthesized cholesterol in anhepatic laboratory diet-fed rats was 10% of the intact rat. In intact rats this cholesterol was mainly ester in lower density lipoproteins, but for anhepatic rats it was virtually only free in high density lipoprotein. Chylomicron cholesterol ester was removed much more slowly from anhepatic than control plasma and returned primarily as free in high density lipoproteins, with the control return 10 times the anhepatic return. Lower density lipoprotein cholesterol ester transfer to an extravascular pool in anhepatic rats was less than 10% of controls. The liver was responsible for 95% of the extravascular lower density lipoprotein ester pool and only 50% of the for high density lipoprotein ester. Despite decreased anhepatic lipoprotein catabolism, the mass of both plasma low and high density lipoproteins progressively decreased indicating an even greater decrease in influx. The anhepatic fractional catabolic rate of apo A1 was similar to controls, but that of apo E was considerably less. Despite the unchanged catabolism of apo A1 and the reduced catabolism of apo E, plasma apo A1 decreased less than apo E after hepatectomy. The anhepatic data confirm the pivotal role of the liver in maintaining plasma low and high density lipoprotein cholesterol concentrations. They suggest that, in addition to its anabolic and catabolic functions, the liver also acts as a reservoir buffering changes in plasma concentration. Images PMID:1569195

  8. Neurotransmitters in rats fed fumonisin B1.

    PubMed

    Porter, J K; Voss, K A; Chamberlain, W J; Bacon, C W; Norred, W P

    1993-03-01

    Fumonisin B1, a toxin produced by Fusarium moniliforme, has been associated with a neurotoxic syndrome in horses known as equine leukoencephlomalacia. Previous investigations showed that F. moniliforme cultured on corn and incorporated into rat chow increased brain 5-hydroxyindoleacetic acid (5HIAA) and 5HIAA: serotonin (5HT) ratios in these animals. Therefore, this study was undertaken to determine whether fumonisin B1 would produce related neurochemical effects in the brain and pineal gland of male and female rats. Rats were fed fumonisin B1 at 15, 50, and 150 ppm for 4 weeks. No differences occurred in brain concentrations of norepinephrine, dopamine, 3,4-dihydroxyphenylacetic acid, 3-methoxytyramine, homovanillic acid, 5HT, 5HIAA, and the 5HIAA to 5HT ratios in either male or female rats, nor where there differences between the sexes. When compared across sexes, the norepinephrine to dopamine ratios were decreased (P < 0.05) in the 150-ppm-treated animals. This may suggest a fumonisin B1-induced imbalance in brain norepinephrine and/or dopamine. No differences were observed in pineal norepinephrine, 5HT, 5HIAA, and the 5HIAA to 5HT ratios. Since fumonisin B1 failed to duplicate the effects of the F. moniliforme-induced imbalances in 5HT and 5HIAA metabolism in the brains of rats, other mycotoxins from F. moniliforme may be responsible for these effects.

  9. Aspartate carbamoyltransferase from rat liver

    PubMed Central

    Bresnick, E.; Mossé, Helena

    1966-01-01

    1. Aspartate-carbamoyltransferase activity was concentrated from rat-liver preparations. Only l-aspartate, β-benzyl-l-aspartate and β-erythro-hydroxy-dl-aspartate were carbamoylated enzymically. The Km for l-aspartate and carbamoyl phosphate have been determined by three methods: colorimetric procedure, radioactive assay with [14C]aspartate and an assay with [14C]carbamoyl phosphate. 2. The Km for aspartate has been determined as a function of the pH; the pK of the functional group at the active site of the enzyme, pKe, was at pH9·0. Enzymic activity was diminished in the presence of N-ethylmaleimide, p-hydroxymercuribenzoate and the heavy metals Ag+, Hg2+, or Zn2+. The inhibitions could be prevented by mercaptoethanol. These findings suggested the association of a thiol group with the enzymic activity. 3. Enzymic activity was also decreased by sodium lauryl sulphate, urea and dioxan. Competitive inhibition (with l-aspartate) was manifested by maleate, succinate, oxaloacetate, β-erythro-hydroxy-dl-aspartate and β-benzyl-l-aspartate. The Ki for most of these inhibitions has been determined. 4. The properties of the liver enzyme are compared with those of Escherichia coli aspartate carbamoyltransferase and the implications of the findings are discussed. PMID:5339547

  10. The rat oocyte synthesises melatonin.

    PubMed

    Sakaguchi, Kenichiro; Itoh, Masanori T; Takahashi, Noriyuki; Tarumi, Wataru; Ishizuka, Bunpei

    2013-01-01

    Melatonin (N-acetyl-5-methoxytryptamine) is an indoleamine originally identified in the pineal gland, where it is synthesised enzymatically from serotonin (5-hydroxytryptamine) by the sequential action of arylalkylamine N-acetyltransferase (AANAT) and acetylserotonin O-methyltransferase (ASMT; also known as hydroxyindole O-methyltransferase). Melatonin directly affects ovarian functions and previous studies have suggested that melatonin is synthesised in the ovary. In the present study, we examined whether AANAT and ASMT are expressed in the adult rat ovary. Reverse transcription-polymerase chain reaction analyses demonstrated that both AANAT and ASMT mRNAs are expressed in the ovary. Western blotting for AANAT protein showed that the ovary, like the pineal gland, contains this enzymatic protein with a molecular mass of 24kDa. Immunohistochemistry revealed that the AANAT protein is localised to the oocyte, corpus luteum and medulla, including mast cells. AANAT protein was found in oocytes at all stages of follicular development, and its levels in oocytes increased progressively throughout follicular development. Furthermore, isolated oocytes metabolised exogenous serotonin to melatonin. These findings demonstrate that melatonin is synthesised from serotonin in oocytes. Melatonin synthesised in the oocyte may be implicated in its own growth or maturation, for example, by acting as a calmodulin antagonist or an antioxidant.

  11. On the rat model of human osteopenias and osteoporoses

    NASA Technical Reports Server (NTRS)

    Frost, Harold M.; Jee, Webster S. S.

    1992-01-01

    The idea that rats cannot model human osteopenias errs. The same mechanisms control gains in bone mass (longitudinal bone growth and modeling drifts) and losses (BMU-based remodeling), in young and aged rats and humans. Furthermore, they respond similarly in rats and man to mechanical influences, hormones, drugs and other agents.

  12. Deficits in reproductive behaviour in septally lesioned female rats.

    PubMed

    Gogate, M G; Brid, S V; Wingkar, K C

    1991-12-01

    Estrous cycle and sexual behaviour were studied in septally lesioned female albino Wistar rats. In lesioned rats the vaginal smears showed continuous diestrus and the females failed to exhibit sexual receptivity during the postoperative period. Ovarian and uterine weights in lesioned rats were also significantly decreased. The results suggest that the septal nuclei exert a modulatory influence on female sexual behaviour. PMID:1816101

  13. EVALUATION OF PERFLUOROOCTANE SULFONATE (PFOS) IN THE RAT BRAIN

    EPA Science Inventory

    This study examined whether there is a differential distribution of PFOS within the brain, and compares adult rats with neonatal rats at an age when formation of the blood-brain barrier is not yet complete (postnatal day 7). Male and female Sprague-Dawley rats (60-70 day old, 4/...

  14. Fetal rat pancreas transplantation in BB rats: immunohistochemical and functional evaluation.

    PubMed

    Yderstraede, K B; Starklint, H; Steinbruchel, D; Jørgensen, T W; Gotfredsen, C F

    1993-01-01

    Spontaneously diabetic BB/Wor rats received either a syngeneic fetal pancreas transplant or adult islets. In the former, 4-8 fetal pancreases were transplanted, and in the latter, 3-5000 islets. Transplantation was performed by transferring a blood clot containing the pancreases or islets to the renal subcapsular space. Insulin therapy was undertaken postoperatively, except in one experiment with adult islets. Of the fetal pancreas transplanted BB rats, 52% became normoglycaemic, and 21% remained so throughout an observation period of 10 months. Nephrectomy caused a prompt return of diabetes. The histological appearance of the grafts transplanted to the diabetic animals closely resembled that of grafts transplanted to normal rats in a parallel series. For comparison a group of BB rats received a syngeneic transplant of isolated adult islets from WF rats or BBW rats. Following adult islet transplantation, 5 out of 6 animals became hyperglycaemic after a median of 20.5 days when no insulin was given post-transplantation. Four out of 5 animals became hyperglycaemic after a median of 23 days when supportive insulin therapy was administered after the transplantation. The results indicate that recurrent diabetes is not inevitable following syngeneic fetal pancreas transplantation to spontaneously diabetic BB rats. Recurrent diabetes was only occasionally associated with mononuclear cell infiltration. Transplanted tissue was well-preserved and vascularized; mega-islets were a constant finding. PMID:8401812

  15. Fetal rat pancreas transplantation in BB rats: immunohistochemical and functional evaluation.

    PubMed

    Yderstraede, K B; Starklint, H; Steinbruchel, D; Jørgensen, T W; Gotfredsen, C F

    1993-01-01

    Spontaneously diabetic BB/Wor rats received either a syngeneic fetal pancreas transplant or adult islets. In the former, 4-8 fetal pancreases were transplanted, and in the latter, 3-5000 islets. Transplantation was performed by transferring a blood clot containing the pancreases or islets to the renal subcapsular space. Insulin therapy was undertaken postoperatively, except in one experiment with adult islets. Of the fetal pancreas transplanted BB rats, 52% became normoglycaemic, and 21% remained so throughout an observation period of 10 months. Nephrectomy caused a prompt return of diabetes. The histological appearance of the grafts transplanted to the diabetic animals closely resembled that of grafts transplanted to normal rats in a parallel series. For comparison a group of BB rats received a syngeneic transplant of isolated adult islets from WF rats or BBW rats. Following adult islet transplantation, 5 out of 6 animals became hyperglycaemic after a median of 20.5 days when no insulin was given post-transplantation. Four out of 5 animals became hyperglycaemic after a median of 23 days when supportive insulin therapy was administered after the transplantation. The results indicate that recurrent diabetes is not inevitable following syngeneic fetal pancreas transplantation to spontaneously diabetic BB rats. Recurrent diabetes was only occasionally associated with mononuclear cell infiltration. Transplanted tissue was well-preserved and vascularized; mega-islets were a constant finding.

  16. Neighborhood Sanitation: Rat Complaints and Rat Control on the Near West Side, Newark, New Jersey and North Hill, Akron, Ohio

    ERIC Educational Resources Information Center

    Margulis, Harry L.

    1978-01-01

    Analyses suggest that monthly rate of change in rat complaints is best explained by procedures which increase agency visibility, time-dependent cycles dictated by agency operation and intervention, and dynamics of a rat population. Effective rat control occurs when blocks are environmentally improved and annual cycle links weakened. (Author/MA)

  17. Daily rhythm of nociception in rats.

    PubMed

    Christina, AJM; Merlin, NJ; Vijaya, C; Jayaprakash, S; Murugesh, N

    2004-03-25

    BACKGROUND: Many behavioral and physiological variables exhibit daily rhythmicity. Few investigations of the daily rhythmicity in nociception have been conducted, and conflicting results have been obtained. The present study evaluated the daily rhythmicity in nociception in Wistar rats. METHODS: Nociception was investigated by Eddy's hot plate method, tail immersion method, and tail clip method. The latency between the noxious stimulus and the animal's response was recorded as reaction time. Separate groups of rats were tested in 4-hour intervals for 24 hours. RESULTS: There was clear daily variation in response latency. Reaction time was shortest a few hours before lights-on and longest at the light-dark transition. CONCLUSION: Nociception exhibits robust daily rhythmicity in rats. Sensitivity to pain is highest late in the dark phase of the light-dark cycle and lowest at the light-dark transition.

  18. Daily rhythm of nociception in rats

    PubMed Central

    Christina, AJM; Merlin, NJ; Vijaya, C; Jayaprakash, S; Murugesh, N

    2004-01-01

    Background Many behavioral and physiological variables exhibit daily rhythmicity. Few investigations of the daily rhythmicity in nociception have been conducted, and conflicting results have been obtained. The present study evaluated the daily rhythmicity in nociception in Wistar rats. Methods Nociception was investigated by Eddy's hot plate method, tail immersion method, and tail clip method. The latency between the noxious stimulus and the animal's response was recorded as reaction time. Separate groups of rats were tested in 4-hour intervals for 24 hours. Results There was clear daily variation in response latency. Reaction time was shortest a few hours before lights-on and longest at the light-dark transition. Conclusion Nociception exhibits robust daily rhythmicity in rats. Sensitivity to pain is highest late in the dark phase of the light-dark cycle and lowest at the light-dark transition. PMID:15043763

  19. Weight control and restraint of laboratory rats

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Van Breda Kolff, K.

    1979-01-01

    The use of restrained and confined rats in some procedures used in combustion toxicology introduces the problems of obtaining rats of the appropriate size for the apparatus, and of identifying any artifacts resulting from the use of restraint alone. Feeding studies indicate that controlled feeding of fast-growing strains such as the Sprague-Dawley can hold rat size essentially constant for significant periods of time. The undesirable aspects are the need to cage the animals individually, with resultant psychological as well as metabolic effects. Restraint studies of slow-growing strains such as the Fischer 344 indicate that denying access to food and water for periods of several hours at a time interrupts normal gain only temporarily.

  20. Placentophagia in Weanling Female Laboratory Rats

    PubMed Central

    Harding, Kaitlyn M.; Lonstein, Joseph S.

    2014-01-01

    Placentophagia is common in parturient mammals and offers physiological and behavioral advantages for mothers. In natural environments, weanlings are often present during the birth of younger siblings, but it is unknown if weanling rats are placentophagic or prefer placenta over other substances. To examine this, primiparous rats were remated during the postpartum estrus and weanling females remained in the nest during their mother’s next parturition. Continuous observation revealed that 58% of weanlings were placentophagic. To determine if this placentophagia occurs away from parturient mothers, weanling females still living in their natal nest were offered placenta, liver, or cake frosting in a novel chamber. They ingested more placenta and liver than frosting. Thus, many weanling female laboratory rats are placentophagic during birth of younger siblings but do not selectively prefer placenta when tested outside their natal nest. Consequences of placentophagia by weanlings are unknown, but it may promote their alloparenting or postpartum mothering. PMID:24604548

  1. Body temperature regulation and thermoneutrality in rats.

    PubMed

    Poole, S; Stephenson, J D

    1977-04-01

    Various concepts of thermoneutrality were considered for a proposed study of the role of hypothalamic amines in temperature regulation of rats. The classic definition, the ambient temperature over which metabolic rate is minimum and constant, gave a range of approximately 28 to 32 degrees C. However, within this temperature range rats were inactive, the inactivity apparently representing a behavioural response to heat stress and itself responsible for the reduced metabolic rate; certain thermoregulatory effectors were also activated to increase heat loss. Therefore an alternative range, 18.0 +/- 1.9 (mean +/- S.D.) to 28.1 +/- 1.0 degrees C, was defined in which rats displayed normal activity, behavioural thermoregulations being absent.

  2. Opportunity Leaves a Trail of 'Rat' Holes

    NASA Technical Reports Server (NTRS)

    2004-01-01

    NASA's Mars Exploration Rover Opportunity's rock abrasion tool, known informally as the 'Rat,' has nibbled seven holes into the slope of 'Endurance Crater.' This image from the rover's navigation camera was released previously (PIA06716) without the Rat holes labeled so that viewers could try to find the holes themselves. Here, the holes have been identified. Starting from the uppermost pictured (closest to the crater rim) to the lowest, the Rat hole targets are: 'Tennessee,' 'Cobblehill,' 'Virginia,' 'London,' 'Grindstone,' 'Kettlestone,' and 'Drammensfjorden.' These holes were drilled on sols 138 (June 13, 2004), 143 (June 18), 145 (June 20), 148 (June 23), 151 (June 26), 153 (June 28) and 161 (July 7), respectively. Each hole is 4.5 centimeters (1.8 inches) in diameter.

  3. Body temperature regulation and thermoneutrality in rats.

    PubMed

    Poole, S; Stephenson, J D

    1977-04-01

    Various concepts of thermoneutrality were considered for a proposed study of the role of hypothalamic amines in temperature regulation of rats. The classic definition, the ambient temperature over which metabolic rate is minimum and constant, gave a range of approximately 28 to 32 degrees C. However, within this temperature range rats were inactive, the inactivity apparently representing a behavioural response to heat stress and itself responsible for the reduced metabolic rate; certain thermoregulatory effectors were also activated to increase heat loss. Therefore an alternative range, 18.0 +/- 1.9 (mean +/- S.D.) to 28.1 +/- 1.0 degrees C, was defined in which rats displayed normal activity, behavioural thermoregulations being absent. PMID:585477

  4. Renin responses to hemorrhage in conscious rats

    SciTech Connect

    Roarty, T.P.; Chadwick. K.J.; Raff, H.

    1986-03-01

    The authors investigated the role of beta adrenergic inhibition on the renin response to graded hemorrhage (hem) in conscious rats. Chronic femoral arterial (for measurement of mean arterial pressure - MAP) and venous (for drug infusion) catheters were implanted at least 5 days before experimentation. Hem was administered in < 2 min. 10 rats (CTL) were exposed to a total of 21 episodes of hemorrhage. 13 rats (B-block) were given 1 mg/kg propranolol hydrochloride iv 20 min prior to hem (24 episodes total). Plasma renin activity (PRA) was measured by radioimmunoassay. Pre-hem PRA levels were measured in the first 1 ml of hem blood. Hem resulted in hem volume-dependent decreases in blood pressure and increase-response to hemorrhage.

  5. Renin responses to hemorrhage to conscious rats

    SciTech Connect

    Roarty, T.P.; Chadwick, K.J.; Raff, H.

    1986-03-01

    The authors investigated the role of beta adrenergic inhibition on the renin response to graded hemorrhage (hem) in conscious rats. Chronic femoral arterial (for measurement of mean arterial pressure - MAP) and venous (for drug infusion) catheters were implanted at least 5 days before experimentation. Hem was administered in < 2 min. 10 rats (CTL) were exposed to a total of 21 episodes of hemorrhage. 13 rats (B-block) were given 1 mg/kg propranolol hydrochloride iv 20 min prior to hem (24 episodes total). Plasma renin activity (PRA) was measured by radioimmunoassay. Pre-hem PRA levels were measured in the first 1 ml of hem blood. Hem resulted in hem volume-dependent decreases in blood pressure and increases in PRA. B-block did not significantly alter the mean renin response to hemorrhage.

  6. Interpretation of male rat renal tubule tumors

    SciTech Connect

    Rodgers, I.S.; Baetcke, K.P.

    1993-12-01

    Based on an analysis of recent scientific studies, a Technical Panel of the U.S. Environmental Protection Agency`s (EPA) Risk Assessment Forum recently advised EPA risk assessors against using information on certain male rat renal tubule tumors to assess human risk under conditions specified in a new Forum report. Risk assessment approaches generally assume that chemicals producing tumors in laboratory animals are a potential cancer hazard to humans. For most chemicals, including classical rodent kidney carcinogens such as N-ethyl-N-hydroxyethylnitrosamine, this extrapolation remains appropriate. Some chemicals, however, induce accumulation of {alpha}{sub 2u}-globulin ({alpha}{sub 2u}-g), a low molecular weight protein, in the male rat kidney. The {alpha}{sub 2u}-g accumulation initiates a sequence of events that appears to lead to renal tubule tumor formation. Female rats and other laboratory mammals administered the same chemicals do not accumulate low molecular weight protein in the kidney, and they do not develop renal tubule tumors. Because humans appear to be more like other laboratory animals than like the male rat, in this special situation, the male rat is not a good model for assessing human risk. The Forum report stresses the need for full scrutiny of a substantial set of data to determine when it is reasonable to presume that renal tumors in male rats are linked to a process involving {alpha}{sub 2u}-g accumulation and to select appropriate procedures for estimating human risks under such circumstances. 92 refs.

  7. Rats exhibit reference-dependent choice behavior.

    PubMed

    Bhatti, Mehwish; Jang, Hyeran; Kralik, Jerald D; Jeong, Jaeseung

    2014-07-01

    Human preferences depend on whether a chosen outcome appears to be a loss or a gain compared with what had been expected, i.e., in comparison to a reference point. Because reference dependence has such a strong influence on human decision-making, it is important to uncover its origins, which will in turn help delineate the underlying mechanisms. It remains unknown whether rats use reference points in decision-making, and yet, the study of rats could help address the question of whether reference dependence is evolutionarily conserved among mammals and could provide a nonhuman animal model to investigate the neural mechanisms underlying this important cognitive process. The aim of the current study was to determine whether rats show reference-dependent choice behavior. We developed a novel paradigm by modifying the "T" maze by installing "pockets" to the left and right of the "T" stem that held reward pellets so rats would potentially develop reference values for each option prior to choice. We found that the rats were indeed sensitive to the way alternatives were presented. That is, they exhibited reference-dependent choice behavior by avoiding the choice option framed as a loss (e.g., having four reward pellets in the pocket, but receiving only one), at least under conditions with certain outcomes and clear differences between the reference and outcome quantities. Despite the small number of rats in this study, this species-level capacity suggests that reference dependence in general and loss aversion in particular may be conserved traits that evolved at or before the emergence of mammals.

  8. Detection of procathepsin D in rat milk.

    PubMed

    Benes, P; Koelsch, G; Dvorak, B; Fusek, M; Vetvicka, V

    2002-09-01

    The presence of procathepsin D, a zymogen of the soluble lysosomal aspartic proteinase cathepsin D, was detected in rat milk using Western blot analysis and assay of proteolytic activity in acidic buffers. No other forms of cathepsin D were found. Two different polyclonal anti-procathepsin D antibodies were used for immunochemical detection of procathepsin D. Both antibodies we found to recognize rat procathepsin D. Proteolytic activity in acidic buffers was detected using a fluorogenic substrate specific for cathepsin D and was abolished by pepstatin A, a specific inhibitor of aspartic proteinases. This study represents third demonstration of presence of procathepsin D in mammal breast milk. Potential sources and physiological functions are discussed.

  9. [Electromagnetic Shielding Alters Behaviour of Rats].

    PubMed

    Temuryants, N A; Kostyuk, A S; Tumanyants, K N

    2015-01-01

    It has been found that long-term electromagnetic shielding (19 hours per day for 10 days) leads to an increase in the duration of passive swimming time in male rats, decrease the duration of active swimming in the "forced swim" test as well as decrease of libido. On the other hand animals kept under the "open field" conditions do not show significant deviations from their normal behavior. Therefore, one could conclude that moderate electromagnetic shielding causes a depression-like state in rats. PMID:26080600

  10. Fenbendazole treatment and litter size in rats.

    PubMed

    Johnston, Nancy A; Bieszczak, Jeremiah R; Verhulst, Steven; Disney, Kimberly E; Montgomery, Kyle E; Toth, Linda A

    2006-11-01

    Fenbendazole is commonly used in laboratory animal medicine as an anthelmintic for elimination of pinworms. It is generally regarded as a safe drug with minimal side effects. In our facility, 2 breeding colonies of rats were treated with fenbendazole to eliminate pinworms. Analysis of the breeding records revealed that feeding Sprague-Dawley rats a diet containing fenbendazole on a continuous basis for 7 consecutive weeks was associated with a significant reduction in litter size. Although the mechanism underlying this effect is unknown, the finding prompts caution when using fenbendazole to treat valuable breeding colonies or strains that are poor breeders.

  11. Aspartame and the rat brain monoaminergic system.

    PubMed

    Perego, C; De Simoni, M G; Fodritto, F; Raimondi, L; Diomede, L; Salmona, M; Algeri, S; Garattini, S

    1988-12-01

    A high dose of aspartame (APM) was administered to rats to study possible effects on brain monoaminergic systems. APM and its metabolite phenylalanine (Phe) were given orally at doses of 1000 and 500 mg/kg, respectively. Significant increases were seen in brain Phe and tyrosine (Tyr) levels. Two different approaches were used to study monoaminergic systems: whole tissue measurements by HPLC-ED and in vivo voltammetry in freely moving rats. Dopamine, serotonin and their metabolites were taken as indexes of neuronal activity. In spite of the high dose used, no modification was found in monoamines or their metabolites in striatum, hippocampus and nucleus accumbens.

  12. The oncogenic action of ionizing radiation on rat skin

    SciTech Connect

    Burns, F.J.

    1991-01-01

    Progress has occurred in several areas corresponding to the specific aims of the proposal: (1) Progression and multiple events in radiation carcinogenesis of rat skin as a function of LET; (2) cell cycle kinetics of irradiated rat epidermis as determined by double labeling and double emulsion autoradiography; (3) oncogene activation detected by in situ hybridization in radiation-induced rat skin tumors; (4) amplification of the c-myc oncogene in radiation-induced rat skin tumors as a function of LET; and (5) transformation of rat skin keratinocytes by ionizing radiation in combination with c-Ki-ras and c-myc oncogenes. 111 refs., 13 figs., 12 tabs.

  13. Metabolism of pyridalyl in rats.

    PubMed

    Nagahori, Hirohisa; Saito, Koichi; Tomigahara, Yoshitaka; Isobe, Naohiko; Kaneko, Hideo

    2009-12-01

    Metabolism of pyridalyl [2,6-dichloro-4-(3,3-dichloroallyloxy)phenyl 3-[5-(trifluoromethyl)-2-pyridyloxy]propyl ether] was examined in male and female Sprague-Dawley rats. After a single oral administration of [dichlorophenyl-(14)C]pyridalyl at 5 or 500 mg/kg, the (14)C concentration in blood reached maxima at 2 to 10 h and then decreased rapidly with a biological half-life of approximately 11 to 12 h. (14)C concentrations in liver, fat, adrenal gland, and spleen were relatively high at a low dose, reaching 2.3 to 2.7, 1.9 to 2.3, 1.1 to 1.9, and 1.4 ppm, respectively, in these tissues at 2 to 24 h after administration. Although (14)C elimination from fat and hair and skin was relatively slow compared with that from other tissues, the total residue on the 7th day was low, in the range of 1.3 to 2.3% of the dose. The (14)C distribution in tissues with a high dose, as examined by whole-body autoradiography, was similar to that observed for the low dose. Results revealed that more than 88% of the dosed radiocarbon was excreted within 1 day after administration, with cumulative (14)C excretion into urine and feces 7 days after administration of 1.7 to 2.6 and 98.7 to 101.7%, respectively. One urinary and fecal major metabolite (resulting from O-dealkylation) and two minor metabolites were identified by NMR and mass spectrometry. Residual (14)C in fat was extracted, and analysis by thin-layer chromatography showed it to be due to pyridalyl itself. No marked sex-related differences were observed in (14)C elimination, (14)C distribution, and metabolites. PMID:19773539

  14. Differential hippocampal protein expression between normal aged rats and aged rats with postoperative cognitive dysfunction: A proteomic analysis.

    PubMed

    Li, Yang; Wang, Saiying; Ran, Ke; Hu, Zhonghua; Liu, Zhaoqian; Duan, Kaiming

    2015-08-01

    The aim of the present study was to investigate the differences in the expression of hippocampal proteins between normal control aged rats and aged rats with postoperative cognitive dysfunction (POCD). A total of 24 aged rats were randomly divided into a surgery group (n=12) and a control group (n=12). The rats in the surgery group were treated with 2 h isoflurane anesthesia and splenectomy, while the rats in the control group received 40% oxygen for 2 h without surgery. The cognitive functions of the two groups were examined using a Y-maze test. The protein expression profiles of the hippocampus of six aged rats (three rats with POCD and three from the normal control group) were assessed using two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time of flight mass spectrometry. A total of three differential proteins were further confirmed between the POCD rats and normal rats using reverse transcription quantitative polymerase chain reaction (RT-qPCR). The expression levels of 21 proteins in the rats with POCD were significantly different compared with the normal control rats. These proteins were functionally clustered to synaptic plasticity (three proteins), oxidative stress (four proteins), energy production (six proteins), neuroinflammation (three proteins) and glutamate metabolism (two proteins). In addition, three proteins (fatty acid binding protein 7, brain, glutamate dehydrogenase 1 and glutamine synthetase), associated with astrocytic function, were significantly different in the rats with POCD compared with those in the normal control (P<0.05). Similar changes in the mRNA expression levels of the three proteins in the hippocampi of POCD rats were also detected using RT-qPCR. Neuroinflammation, glutamate toxicity and oxidative stress were possibly involved in the pathological mechanism underlying POCD in aged rats. In addition, astrocytes may also be important in POCD in aged rats. PMID:25936412

  15. Rescue from dwarfism by thyroid function compensation in rdw rats.

    PubMed

    Furudate, Sen-ichi; Ono, Masao; Shibayama, Keiko; Ohyama, Yoshihide; Kuwada, Masahiro; Kimura, Toshimi; Kameya, Toru

    2005-10-01

    The rdw rat was initially reported as having hereditary dwarfism caused by pituitary dysfunction. Subsequent studies on the rdw rat, however, have demonstrated that the primary cause of rdw dwarfism is present in the thyroid gland but not in the pituitary gland. The primary cause of rdw rat disorders is a missense mutation of the thyroglobulin (Tg) gene by a one-point mutation. In the present study, we attempted to rescue the dwarfism of the rdw rats using a diet supplemented with thyroid powder (T-powder) and a thyroid graft (T-graft). The infants of the rdw rat were successfully raised to a mature stage body weight, accompanied by elevation of serum growth hormone (GH) and prolactin (PRL), by the T-powder. Furthermore, the T-graft successfully increased the body weight with fertility. The serum GH and PRL levels in the T-graft rdw rat significantly increased. The serum thyroid-stimulating hormone (TSH) levels in the T-graft rdw rat were significantly decreased but were significantly higher than those in the control rat. The GH and PRL mRNA expression in the rdw rat with the T-graft was virtually the same as that of the control, but the TSH beta mRNA differed from that of the control rats. Thus, the dwarfism in the rdw rat is rescued by thyroid function compensation, such as that afforded by T-powder and T-graft.

  16. [Foci of the rat mite Ornithonyssus bacoti (Mesostigmata, Macronyssidae) and rat-mite dermatitis in Moscow].

    PubMed

    Lopatina, Iu V; Sokolova, T V; Niiazova, M V

    1992-01-01

    High density of the rat population in Moscow in 1990-1991 resulted in the appearance of Ornithonyssus bacoti foci and of cases of the rat-mite dermatitis in humans. A total of 36 foci of the disease were examined and eradicated. A method for the detection of such foci has been developed. Two types of foci are distinguished, communal and industrial, and their specific features as regards the rodent and mite populations and clinical features of dermatitis in humans are described. A system of measures for liquidation of foci of rat mites is suggested, including rat and mite eradication and treatment of the patients. Specific features of these measures for various types of foci and in case of a focus reappearance are enumerated. PMID:1299760

  17. Hepatitis E Virus Genotype 3 in Wild Rats, United States

    PubMed Central

    Volk, Kylie; Van Den Bussche, Ronald A.

    2012-01-01

    The role of rodents in the epidemiology of zoonotic hepatitis E virus (HEV) infection has been a subject of considerable debate. Seroprevalence studies suggest widespread HEV infection in commensal Rattus spp. rats, but experimental transmission has been largely unsuccessful and recovery of zoonotic genotype 3 HEV RNA from wild Rattus spp. rats has never been confirmed. We surveyed R. rattus and R. norvegicus rats from across the United States and several international populations by using a hemi-nested reverse transcription PCR approach. We isolated HEV RNA in liver tissues from 35 of 446 rats examined. All but 1 of these isolates was relegated to the zoonotic HEV genotype 3, and the remaining sequence represented the recently discovered rat genotype from the United States and Germany. HEV-positive rats were detected in urban and remote localities. Genetic analyses suggest all HEV genotype 3 isolates obtained from wild Rattus spp. rats were closely related. PMID:22840202

  18. Core temperature of tailless rats exposed to centrifugation

    NASA Technical Reports Server (NTRS)

    Monson, C. B.; Oyama, J.

    1984-01-01

    The role of the tail in the altered thermoregulation of rats during acute exposure to hypergravity was investigated, using groups of rats of two ages: 55 days (young) and 138 days (old). Rectal and foot temperature changes were measured in intact and tailless rats subjected to 1 h centrifugation of 2.8 G, with preceding (1 h) and following (1-3 h) 1 G periods. At 22 C, the loss of body heat from the tail per se does not measurably contribute to the hypothermia induced by hypergravity. However, the heat loss from the feet was greater in the tailless rats than in the intact rats from the young group of animals, although there was no significant difference between the tailless and intact rats in the old animal group. It is concluded that the inhibition of heat production is a significant factor in the hypothermia of centrifuged tailless rats, as it has been previously shown to be in the intact animals.

  19. Aging effects on oxidative phosphorylation in rat adrenocortical mitochondria.

    PubMed

    Solinas, Paola; Fujioka, Hisashi; Radivoyevitch, Tomas; Tandler, Bernard; Hoppel, Charles L

    2014-06-01

    Does aging in itself lead to alteration in adrenocortical mitochondrial oxidative phosphorylation? Mitochondria from Fischer 344 (F344) rats (6 and 24 months old), Brown Norway rats (6 and 32 months old) and F344-Brown Norway hybrid rats (6 and 30 months old) were compared. Mitochondria were isolated from extirpated adrenal cortex. The yields of mitochondria were quantitatively similar in all rat strains irrespective of age. In order to assess the activity of each mitochondrial complex, several different substrates were tested and the rate of oxidative phosphorylation measured. Aging does not affect mitochondrial activity except in the F344 rat adrenal cortex where the maximal ADP-stimulated oxidative phosphorylation decreased with age. We hypothesize that impaired synthesis of steroid hormones by the adrenal cortex with age in F344 rats might be due to decreased adrenocortical mitochondrial oxidative phosphorylation. We conclude that aging results in adrenocortical mitochondria effects that are non-uniform across different rat strains.

  20. Hepatitis E virus genotype 3 in wild rats, United States.

    PubMed

    Lack, Justin B; Volk, Kylie; Van Den Bussche, Ronald A

    2012-08-01

    The role of rodents in the epidemiology of zoonotic hepatitis E virus (HEV) infection has been a subject of considerable debate. Seroprevalence studies suggest widespread HEV infection in commensal Rattus spp. rats, but experimental transmission has been largely unsuccessful and recovery of zoonotic genotype 3 HEV RNA from wild Rattus spp. rats has never been confirmed. We surveyed R. rattus and R. norvegicus rats from across the United States and several international populations by using a hemi-nested reverse transcription PCR approach. We isolated HEV RNA in liver tissues from 35 of 446 rats examined. All but 1 of these isolates was relegated to the zoonotic HEV genotype 3, and the remaining sequence represented the recently discovered rat genotype from the United States and Germany. HEV-positive rats were detected in urban and remote localities. Genetic analyses suggest all HEV genotype 3 isolates obtained from wild Rattus spp. rats were closely related. PMID:22840202

  1. Witnessing traumatic events causes severe behavioral impairments in rats.

    PubMed

    Patki, Gaurav; Solanki, Naimesh; Salim, Samina

    2014-12-01

    Witnessing a traumatic event but not directly experiencing it can be psychologically quite damaging. In North America alone, ∼30% of individuals who witness a traumatic event develop post-traumatic stress disorder (PTSD). While effects of direct trauma are evident, consequences of indirect or secondary trauma are often ignored. Also unclear is the role of social support in the consequences of these experiences. The social defeat paradigm, which involves aggressive encounters by a large Long-Evans male rat (resident) towards a smaller Sprague-Dawley male rat (intruder), is considered a rodent model of PTSD. We have modified this model to create a trauma witness model (TWM) and have used our TWM model to also evaluate social support effects. Basically, when an intruder rat is placed into the home cage of a resident rat, it encounters an agonistic behavior resulting in intruder subordination. The socially defeated intruder is designated the SD rat. A second rat, the cage mate of the SD, is positioned to witness the event and is the trauma witnessing (TW) rat. Experiments were performed in two different experimental conditions. In one, the SD and TW rats were cagemates and acclimatized together. Then, one SD rat was subjected to three sessions of social defeat for 7 d. TW rat witnessed these events. After each social defeat exposure, the TW and SD rats were housed together. In the second, the TW and SD rats were housed separately starting after the first defeat. At the end of each protocol, depression-anxiety-like behavior and memory tests were conducted on the SD and TW rats, blood withdrawn and specific organs collected. Witnessing traumatic events led to depression- and anxiety-like behavior and produced memory deficits in TW rats associated with elevated corticosterone levels.

  2. Persistent Rat Virus Infection in Smooth Muscle of Euthymic and Athymic Rats

    PubMed Central

    Jacoby, Robert O.; Johnson, Elizabeth A.; Paturzo, Frank X.; Ball-Goodrich, Lisa

    2000-01-01

    Rat virus (RV) infection can cause disease or disrupt responses that rely on cell proliferation. Therefore, persistent infection has the potential to amplify RV interference with research. As a step toward determining underlying mechanisms of persistence, we compared acute and persistent RV infections in infant euthymic and athymic rats inoculated oronasally with the University of Massachusetts strain of RV. Rats were assessed by virus isolation, in situ hybridization, and serology. Selected tissues also were analyzed by Southern blotting or immunohistochemistry. Virus was widely disseminated during acute infection in rats of both phenotypes, whereas vascular smooth muscle cells (SMC) were the primary targets during persistent infection. The prevalence of virus-positive cells remained moderate to high in athymic rats through 8 weeks but decreased in euthymic rats by 2 weeks, coincident with seroconversion and perivascular infiltration of mononuclear cells. Virus-positive pneumocytes and renal tubular epithelial cells also were detected through 8 weeks, implying that kidney and lung excrete virus during persistent infection. Viral mRNA was detected in SMC of both phenotypes through 8 weeks, indicating that persistent infection includes virus replication. However, only half of the SMC containing viral mRNA at 4 weeks stained for proliferating cell nuclear antigen, a protein expressed in cycling cells. The results demonstrate that vasculotropism is a significant feature of persistent infection, that virus replication continues during persistent infection, and that host immunity reduces, but does not eliminate, infection. PMID:11090184

  3. Construction and characterization of an infectious cDNA clone of rat hepatitis E virus.

    PubMed

    Li, Tian-Cheng; Yang, Tingting; Yoshizaki, Sayaka; Ami, Yasushi; Suzaki, Yuriko; Ishii, Koji; Haga, Kei; Nakamura, Tomofumi; Ochiai, Susumu; Takaji, Wakita; Johne, Reimar

    2015-06-01

    Rat hepatitis E virus (HEV) is related to human HEV and has been detected in wild rats worldwide. Here, the complete genome of rat HEV strain R63/DEU/2009 was cloned downstream of the T7 RNA polymerase promoter and capped genomic RNA generated by in vitro transcription was injected into nude rats. Rat HEV RNA could be detected in serum and faeces of rats injected intrahepatically, but not in those injected intravenously. Rat HEV RNA-positive faecal suspension was intravenously inoculated into nude rats and Wistar rats leading to rat HEV RNA detection in serum and faeces of nude rats, and to seroconversion in Wistar rats. In addition, rat HEV was isolated in PLC/PRF/5 cells from the rat HEV RNA-positive faecal suspension of nude rats and then passaged. The cell culture supernatant was infectious for nude rats. Genome analysis identified nine point mutations of the cell-culture-passaged virus in comparison with the originally cloned rat HEV genome. The results indicated that infectious rat HEV could be generated from the cDNA clone. As rats are widely used and well-characterized laboratory animals, studies on genetically engineered rat HEV may provide novel insights into organ tropism, replication and excretion kinetics as well as immunological changes induced by hepeviruses.

  4. Construction and characterization of an infectious cDNA clone of rat hepatitis E virus.

    PubMed

    Li, Tian-Cheng; Yang, Tingting; Yoshizaki, Sayaka; Ami, Yasushi; Suzaki, Yuriko; Ishii, Koji; Haga, Kei; Nakamura, Tomofumi; Ochiai, Susumu; Takaji, Wakita; Johne, Reimar

    2015-06-01

    Rat hepatitis E virus (HEV) is related to human HEV and has been detected in wild rats worldwide. Here, the complete genome of rat HEV strain R63/DEU/2009 was cloned downstream of the T7 RNA polymerase promoter and capped genomic RNA generated by in vitro transcription was injected into nude rats. Rat HEV RNA could be detected in serum and faeces of rats injected intrahepatically, but not in those injected intravenously. Rat HEV RNA-positive faecal suspension was intravenously inoculated into nude rats and Wistar rats leading to rat HEV RNA detection in serum and faeces of nude rats, and to seroconversion in Wistar rats. In addition, rat HEV was isolated in PLC/PRF/5 cells from the rat HEV RNA-positive faecal suspension of nude rats and then passaged. The cell culture supernatant was infectious for nude rats. Genome analysis identified nine point mutations of the cell-culture-passaged virus in comparison with the originally cloned rat HEV genome. The results indicated that infectious rat HEV could be generated from the cDNA clone. As rats are widely used and well-characterized laboratory animals, studies on genetically engineered rat HEV may provide novel insights into organ tropism, replication and excretion kinetics as well as immunological changes induced by hepeviruses. PMID:25634930

  5. Okara ameliorates glucose tolerance in GK rats.

    PubMed

    Hosokawa, Masaya; Katsukawa, Michiko; Tanaka, Hiroshi; Fukuda, Hitomi; Okuno, Sonomi; Tsuda, Kinsuke; Iritani, Nobuko

    2016-05-01

    Okara, a food by-product from the production of tofu and soy milk, is rich in three beneficial components: insoluble dietary fiber, β-conglycinin, and isoflavones. Although isoflavones and β-conglycinin have recently been shown to improve glucose tolerance, the effects of okara have not yet been elucidated. Therefore, we herein investigated the effects of okara on glucose tolerance in Goto-Kakizaki (GK) rats, a representative animal model of Japanese type 2 diabetes. Male GK rats were fed a 10% lard diet with or without 5% dry okara powder for 2 weeks and an oral glucose tolerance test was performed. Rats were then fed each diet for another week and sacrificed. The expression of genes that are the master regulators of glucose metabolism in adipose tissue was subsequently examined. No significant differences were observed in body weight gain or food intake between the two groups of GK rats. In the oral glucose tolerance test, increases in plasma glucose levels were suppressed by the okara diet. The mRNA expression levels of PPARγ, adiponectin, and GLUT4, which up-regulate the effects of insulin, were increased in epididymal adipose tissue by the okara diet. These results suggest that okara provides a useful means for treating type 2 diabetes. PMID:27257347

  6. Liver uptake of biguanides in rats.

    PubMed

    Sogame, Yoshihisa; Kitamura, Atsushi; Yabuki, Masashi; Komuro, Setsuko

    2011-09-01

    Metformin is an oral antihyperglycaemic agent widely used in the management of non-insulin-dependent diabetes mellitus. The liver is the primary target, metformin being taken up into human and rat hepatocytes via an active transport mechanism. The present study was designed to compare hepatic uptake of two biguanides, metformin and phenformin, in vitro and in vivo. In in vitro experiments, performed using rat cryopreserved hepatocytes, phenformin exhibited a much higher affinity and transport than metformin, with marked differences in kinetics. The K(m) values for metformin and phenformin were 404 and 5.17μM, respectively, with CLint (V(max)/K(m)) values 1.58μl/min per 10(6) cells and 34.7μl/min per 10(6) cells. In in vivo experiments, when (14)C-metformin and (14)C-phenformin were given orally to male rats at a dose of 50mg/kg, the liver concentrations of radioactivity at 0.5 hour after dosing were 21.5μg eq./g with metformin but 147.1μg eq./g for phenformin, ratios of liver to plasma concentrations being 4.2 and 61.3, respectively. In conclusion, the results suggest that uptake of biguanides by rat hepatocytes is in line with the liver distribution found in vivo, phenformin being more efficiently taken up by liver than metformin after oral administration.

  7. Lobeline produces conditioned taste avoidance in rats.

    PubMed

    Harrod, S B; Dwoskin, L P; Bardo, M T

    2004-05-01

    Previous results indicate that pretreatment with lobeline attenuates methamphetamine (METH) self-administration in rats, but not by acting as a substitute reinforcer. Given these findings, it has been suggested that lobeline may serve as a useful pharmacotherapy for psychostimulant abuse. However, because lobeline produces emesis and nausea in humans, the present study examined whether lobeline has direct effects on taste avoidance behavior in rats within the same dose range shown previously to decrease METH self-administration. Two experiments utilized a Pavlovian conditioning procedure to determine if lobeline produces conditioned taste avoidance (CTA) in rats. In Experiments 1 and 2, rats consumed either novel milk or salt solutions, respectively, and within 10 min, were injected with lobeline (0.3-3.0 mg/kg) or METH (0.3-3.0 mg/kg). A single-bottle test conducted 48 h after flavor-drug pairings indicated that the dose of lobeline that reduced METH self-administration in a previous study (i.e., 3.0 mg/kg) also produced reliable CTA for milk and salt solution. These findings suggest a need to develop lobeline analogs that reduce METH self-administration, but do not produce CTA following the consumption of a novel solution.

  8. Baroreflex Function in Rats after Simulated Microgravity

    NASA Technical Reports Server (NTRS)

    Hasser, Eileen M.

    1997-01-01

    Prolonged exposure of humans to decreased gravitational forces during spaceflight results in a number of adverse cardiovascular consequences, often referred to as cardiovascular deconditioning. Prominent among these negative cardiovascular effects are orthostatic intolerance and decreased exercise capacity. Rat hindlimb unweighting is an animal model which simulates weightlessness, and results in similar cardiovascular consequences. Cardiovascular reflexes, including arterial and cardiopulmonary baroreflexes, are required for normal adjustment to both orthostatic challenges and exercise. Therefore, the orthostatic intolerance and decreased exercise capacity associated with exposure to microgravity may be due to cardiovascular reflex dysfunction. The proposed studies will test the general hypothesis that hindlimb unweighting in rats results in impaired autonomic reflex control of the sympathetic nervous system. Specifically, we hypothesize that the ability to reflexly increase sympathetic nerve activity in response to decreases in arterial pressure or blood volume will be blunted due to hindlimb unweighting. There are 3 specific aims: (1) To evaluate arterial and cardiopulmonary baroreflex control of renal and lumbar sympathetic nerve activity in conscious rats subjected to 14 days of hindlimb unweighting; (2) To examine the interaction between arterial and cardiopulmonary baroreflex control of sympathetic nerve activity in conscious hindlimb unweighted rats; (3) to evaluate changes in afferent and/or central nervous system mechanisms in baroreflex regulation of the sympathetic nervous system. These experiments will provide information related to potential mechanisms for orthostatic and exercise intolerance due to microgravity.

  9. Shifts in the psychophysical function in rats.

    PubMed

    Guilhardi, Paulo; Macinnis, Mika L M; Church, Russell M; Machado, Armando

    2007-06-01

    The primary goal was to compare results from a free-operant procedure with pigeons [Machado, A., Guilhardi, P., 2000. Shifts in the psychometric function and their implications for models of timing. J. Exp. Anal. Behav. 74, 25-54, Experiment 2] with new results obtained with rats. The secondary goal was to compare the results of both experiments with dependent variables that were not used in the original publication. As in the original study with pigeons, rats were trained on a two-alternative free-operant psychophysical procedure in which left lever press responses were reinforced during the first and second quarters of a 60-s trial, and right lever press responses were reinforced during the third and fourth quarters of the trial. The quarters were reinforced according to four independent variable interval (VI) schedules of reinforcement. The VI duration was manipulated in each quarter, and shifts in the psychophysical functions that relate response rate with time since trial onset were measured. The results obtained with rats were consistent with those previously obtained with pigeons. In addition, results not originally reported were also consistent between rats and pigeons, and provided insights into the perception, memory, and decision processes in Scalar Expectancy Theory and Learning-to-Time Theory.

  10. Pack rats (Neotoma spp.): Keystone ecological engineers?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The potential role of two species of pack rats (Neotoma albigula and Neotoma micropus) as keystone ecological engineers was examined by estimating the species diversity of invertebrates living in the nest middens, and nitrogen mineralization rates in soils associated with the middens. Although pack-...

  11. Central action of phenylethylamine in rats.

    PubMed

    Jagiełło-Wójtowicz, E

    1981-01-01

    Phenylethylamine (PEA), 10, 50 and 100 microgram/rat ivc depressed the spontaneous and explorative motor activities, did not affect the body temperature and potentiated the action of hypnotics. The PEA-induced depression of motor activity was antagonized by spiperone, phenoxybenzamine, propranolol and, slightly, by alpha-MT. In rats with total chemical destruction of catecholamine neurons and in rats with selective lesion of dopamine neurons, PEA increased motor activity. Similar effect was observed after administration of reserpine, reserpine together with 6-hydroxydopamine and yohimbine. PEA potentiated the amphetamine and apomorphine stereotypy but inhibited amphetamine hypermotility: in the latter experiment slight periodical stereotyped head movements were observed. PEA did not affect haloperidol and fluphenazine induced catalepsy. It did not change the immobility period in the behavioral despair test. In doses of 0 . 1, 1 and 10 mg/kg iv it potentiated flexor reflex of the hind paw of the spinal rat. Phentolamine (10 mg/kg iv) and propranolol (5 mg/kg iv) slightly potentiated the stimulatory effect of PEA. In doses of 50 and 100 microgram ivc PEA did not affect the level and utilization of noradrenaline, and did not change the level of dopamine but depressed its utilization in the cerebral cortex, striatum and hippocampus. PMID:7196039

  12. Consensus Modeling of Oral Rat Acute Toxicity

    EPA Science Inventory

    An acute toxicity dataset (oral rat LD50) with about 7400 compounds was compiled from the ChemIDplus database. This dataset was divided into a modeling set and a prediction set. The compounds in the prediction set were selected so that they were present in the modeling set used...

  13. The Helsinki Rat Microsurgical Sidewall Aneurysm Model

    PubMed Central

    Marbacher, Serge; Marjamaa, Johan; Abdelhameed, Essam; Hernesniemi, Juha; Niemelä, Mika; Frösen, Juhana

    2014-01-01

    Experimental saccular aneurysm models are necessary for testing novel surgical and endovascular treatment options and devices before they are introduced into clinical practice. Furthermore, experimental models are needed to elucidate the complex aneurysm biology leading to rupture of saccular aneurysms. Several different kinds of experimental models for saccular aneurysms have been established in different species. Many of them, however, require special skills, expensive equipment, or special environments, which limits their widespread use. A simple, robust, and inexpensive experimental model is needed as a standardized tool that can be used in a standardized manner in various institutions. The microsurgical rat abdominal aortic sidewall aneurysm model combines the possibility to study both novel endovascular treatment strategies and the molecular basis of aneurysm biology in a standardized and inexpensive manner. Standardized grafts by means of shape, size, and geometry are harvested from a donor rat's descending thoracic aorta and then transplanted to a syngenic recipient rat. The aneurysms are sutured end-to-side with continuous or interrupted 9-0 nylon sutures to the infrarenal abdominal aorta. We present step-by-step procedural instructions, information on necessary equipment, and discuss important anatomical and surgical details for successful microsurgical creation of an abdominal aortic sidewall aneurysm in the rat. PMID:25350840

  14. Voluntary Oral Administration of Losartan in Rats.

    PubMed

    Diogo, Lucília N; Faustino, Inês V; Afonso, Ricardo A; Pereira, Sofia A; Monteiro, Emília C; Santos, Ana I

    2015-09-01

    Gavage is a widely performed technique for daily dosing in laboratory rodents. Although effective, gavage comprises a sequence of potentially stressful procedures for laboratory animals that may introduce bias into experimental results, especially when the drugs to be tested interfere with stress-dependent parameters. We aimed to test vehicles suitable for drug delivery by voluntary ingestion in rats. Specifically, Male Wistar rats (age, 2 to 3 mo) were used to test nut paste (NUT), peanut butter (PB), and sugar paste (SUG) as vehicles for long-term voluntary oral administration of losartan, an angiotensin II receptor blocker. Vehicles were administered for 28 d without drug to assess effects on the glucose level and serum lipid profile. Losartan was mixed with vehicles and either offered to the rats or administered by gavage (14 d) for subsequent quantification of losartan plasma levels by HPLC. After a 2-d acclimation period, all rats voluntarily ate the vehicles, either alone or mixed with losartan. NUT administration reduced blood glucose levels. The SUG group had higher concentrations of losartan than did the gavage group, without changes in lipid and glucose profiles. Our results showed that NUT, PB, and SUG all are viable for daily single-dose voluntary ingestion of losartan and that SUG was the best alternative overall. Drug bioavailability was not reduced after voluntary ingestion, suggesting that this method is highly effective for chronic oral administration of losartan to laboratory rodents. PMID:26424254

  15. Dermal absorption of inorganic germanium in rats.

    PubMed

    Yokoi, Katsuhiko; Kawaai, Takae; Konomi, Aki; Uchida, Yuka

    2008-11-01

    So-called germanium 'health' products including dietary supplements, cosmetics, accessories, and warm bath service containing germanium compounds and metalloid are popular in Japan. Subchronic and chronic oral exposure of germanium dioxide (GeO(2)), popular chemical form of inorganic germanium causes severe germanium toxicosis including death and kidney dysfunction in humans and experimental animals. Intestinal absorption of neutralized GeO(2) or germanate is almost complete in humans and animals. However, it is not known whether germanium is cutaneously absorbed. We tested dermal absorption of neutralized GeO(2) or germanate using male F344/N rats. Three groups of rats were treated with a 3-h topical application of hydrophilic ointment containing graded level of neutralized GeO(2) (pH 7.4): 0, 0.21 and 0.42 mg GeO(2)/g. Germanium concentration in blood and tissues sampled from rats after topical application of inorganic germanium was measured by inductively coupled plasma-mass spectrometry. Animals topically applied 0.42 mg GeO(2)/g ointment had significantly higher germanium concentrations in plasma, liver, and kidney than those of rats that received no topical germanium. The results indicate that skin is permeable to inorganic germanium ion or germanate and recurrent exposure of germanium compounds may pose a potential health hazard.

  16. Cardiac Muscle Studies with Rat Ventricular Strips

    ERIC Educational Resources Information Center

    Whitten, Bert K.; Faleschini, Richard J.

    1977-01-01

    Details undergraduate physiology laboratory experiments that demonstrate mechanical properties of cardiac muscle, using strips from the ventricle of a rat heart. Includes procedures for obtaining length-tension curves, demonstrating the role of calcium in excitation-contraction coupling, and showing effects of several cardiovascular drugs…

  17. On the absorption of alendronate in rats.

    PubMed

    Lin, J H; Chen, I W; deLuna, F A

    1994-12-01

    Alendronate is an antiosteolytic agent under investigation for the treatment of a number of bone disorders. Since the compound is a zwitterion with five pKa values and is completely ionized in the intestine at the physiological pH, absorption is poor; less than 1% of an oral dose is available systemically in rats. In the present studies, absorption was found to be predominantly in the upper part of the small intestine. Administration of buffered solutions of alendronate (pH 2-11) did not improve absorption. Whereas food markedly impaired the absorption of alendronate, EDTA enhanced absorption in a dose-dependent manner. Pretreatment of rats with ulcerogenic agents, mepirizole, acetylsalicylic acid, or indomethacin, resulted in a 3-7-fold increase in the oral absorption of alendronate. The absorption of phenol red, added as an indicator of intestinal tissue damage, was also increased in rats with experimental peptic ulcers. The enhanced absorption of alendronate observed in rats with experimental peptic ulcers was attributed to the alteration of the integrity of the intestinal membrane. PMID:7891304

  18. MODELING OPERANT BEHAVIOR IN THE PARKINSONIAN RAT

    PubMed Central

    Avila, Irene; Reilly, Mark P.; Sanabria, Federico; Posadas-Sánchez, Diana; Chavez, Claudia L.; Banerjee, Nikhil; Killeen, Peter; Castañeda, Edward

    2009-01-01

    Mathematical principles of reinforcement (MPR; Killeen, 1994) is a quantitative model of operant behavior that contains 3 parameters representing motor capacity (δ), motivation (a), and short term memory (λ). The present study applied MPR to characterize the effects of bilateral infusions of 6-OHDA into the substantia nigra pars compacta in the rat, a model of Parkinson’s disease. Rats were trained to lever press under a 5-component fixed ratio (5, 15, 30, 60, and 100) schedule of food reinforcement. Rats were tested for 15 days prior to dopamine lesions and again for 15 days post-lesion. To characterize functional loss relative to lesion size, rats were grouped according to the extent and the degree of lateralization of their dopamine loss. Response rates decreased as a function of dopamine depletion, primarily at intermediate ratios. MPR accounted for 98% of variance in pre- and post-lesion response rates. Consistent with reported disruptions in motor behavior induced by dopaminergic lesions, estimates of δ increased when dopamine was severely depleted. There was no support for different estimates of a based on pre- and post-lesion performance of any lesion group, suggesting that dopamine loss has negligible effects on incentive motivation. The present study demonstrates the usefulness of combining operant techniques with a theoretical model to better understand the effects of a neurochemical manipulation. PMID:19073222

  19. METABOLISM AND DOSIMETRY OF VINCLOZOLIN IN RAT

    EPA Science Inventory

    Vinclozolin (V) is an agricultural fungicide. V administered to rats is hydrolyzed to 2-[[(3,5-dichlorophenyl)-carbamoyl]oxy]-2-methyl-3-butenoic acid (M1) and 3',5'-dichloro-2-hydroxy-2-methylbut-3-enanilide (M2). V, M1and M2 are antiandrogenic by interacting with the androgen r...

  20. Voluntary Oral Administration of Losartan in Rats.

    PubMed

    Diogo, Lucília N; Faustino, Inês V; Afonso, Ricardo A; Pereira, Sofia A; Monteiro, Emília C; Santos, Ana I

    2015-09-01

    Gavage is a widely performed technique for daily dosing in laboratory rodents. Although effective, gavage comprises a sequence of potentially stressful procedures for laboratory animals that may introduce bias into experimental results, especially when the drugs to be tested interfere with stress-dependent parameters. We aimed to test vehicles suitable for drug delivery by voluntary ingestion in rats. Specifically, Male Wistar rats (age, 2 to 3 mo) were used to test nut paste (NUT), peanut butter (PB), and sugar paste (SUG) as vehicles for long-term voluntary oral administration of losartan, an angiotensin II receptor blocker. Vehicles were administered for 28 d without drug to assess effects on the glucose level and serum lipid profile. Losartan was mixed with vehicles and either offered to the rats or administered by gavage (14 d) for subsequent quantification of losartan plasma levels by HPLC. After a 2-d acclimation period, all rats voluntarily ate the vehicles, either alone or mixed with losartan. NUT administration reduced blood glucose levels. The SUG group had higher concentrations of losartan than did the gavage group, without changes in lipid and glucose profiles. Our results showed that NUT, PB, and SUG all are viable for daily single-dose voluntary ingestion of losartan and that SUG was the best alternative overall. Drug bioavailability was not reduced after voluntary ingestion, suggesting that this method is highly effective for chronic oral administration of losartan to laboratory rodents.

  1. Voluntary Oral Administration of Losartan in Rats

    PubMed Central

    Diogo, Lucília N; Faustino, Inês V; Afonso, Ricardo A; Pereira, Sofia A; Monteiro, Emília C; Santos, Ana I

    2015-01-01

    Gavage is a widely performed technique for daily dosing in laboratory rodents. Although effective, gavage comprises a sequence of potentially stressful procedures for laboratory animals that may introduce bias into experimental results, especially when the drugs to be tested interfere with stress-dependent parameters. We aimed to test vehicles suitable for drug delivery by voluntary ingestion in rats. Specifically, Male Wistar rats (age, 2 to 3 mo) were used to test nut paste (NUT), peanut butter (PB), and sugar paste (SUG) as vehicles for long-term voluntary oral administration of losartan, an angiotensin II receptor blocker. Vehicles were administered for 28 d without drug to assess effects on the glucose level and serum lipid profile. Losartan was mixed with vehicles and either offered to the rats or administered by gavage (14 d) for subsequent quantification of losartan plasma levels by HPLC. After a 2-d acclimation period, all rats voluntarily ate the vehicles, either alone or mixed with losartan. NUT administration reduced blood glucose levels. The SUG group had higher concentrations of losartan than did the gavage group, without changes in lipid and glucose profiles. Our results showed that NUT, PB, and SUG all are viable for daily single-dose voluntary ingestion of losartan and that SUG was the best alternative overall. Drug bioavailability was not reduced after voluntary ingestion, suggesting that this method is highly effective for chronic oral administration of losartan to laboratory rodents. PMID:26424254

  2. NAT THE RAT - PUPIL'S BOOK. (TITLE SUPPLIED).

    ERIC Educational Resources Information Center

    ROJAS, PAULINE M.; AND OTHERS

    THE EXPERIMENTAL EDITION OF "NAT THE RAT" REPRESENTS LEVEL TWO OF THE "MIAMI LINGISTIC READERS" DESIGNED TO BE USED IN TEACHING BEGINNING READING TO PUPILS WHOSE PRESCHOOL LANGUAGE WAS OTHER THAN ENGLISH. THE FIVE MAJOR CHARACTERS IN THE STORY ARE INTRODUCED ON THE FIRST FIVE PAGES OF THE PUPILS' BOOK. ILLUSTRATIONS (BLACK AND WHITE) TO REINFORCE…

  3. The rat choledochojejunostomy model for microsurgical training

    PubMed Central

    Lee, Jun Suh

    2016-01-01

    Purpose The feasibility of a rat choledochojejunostomy (CJ) training model was investigated, as an introductory model to microsurgery for general surgeons. Methods Roux-en-Y CJ was performed on 20 rats. Interrupted 10-0 prolene sutures were used to perform CJ. The animals were observed for 7 days and sacrificed and examined. Results The rats were divided into 2 groups of 10 based on surgical order. The CJ time showed a significant decrease from 36.2 ± 5.6 minutes in group 1 to 29.4 ± 5.7 minutes in group 2 (P = 0.015). The bile leakage rate was 40% in group 1 and 10% in group 2. The survival time was 5.4 ± 2.2 days in group 1 and 7 days in group 2 (P = 0.049). Conclusion The rat CJ training model is a feasible introductory model for general surgeons with no previous experience in microsurgery. PMID:27186568

  4. Methimazole slows hepatocyte streaming in rats.

    PubMed

    Oren, R; Zajicek, G; Maaravi, Y; Kenet, G; Karmely, F; Hubert, A; Raanani, P; Arber, N

    1997-07-01

    Hepatocytes are hypothesized to continually stream from the portal tract to the terminal hepatic vein. By this model, when a cell divides, one of its progeny replaces the dividing ancestor and the other is displaced into a more remote location. The present experiment aims to demonstrate that hypothyroidism affects liver cell turnover. Thirty male adult rats were divided into two groups. One received methimazole for two weeks and the other served as control. Each rat was injected intraperitoneally with 18.5 KBq [3H]thymidine/g body weight. Rats were killed after 1 hr and two and four weeks. Autoradiography was done. The distance of the labeled cells from the portal tract was measured. The mean TSH levels of the methimazole-treated group and controls were 1.45 and 0.25 mM/liter, respectively (P < 0.01). Hepatocyte streaming was lower in hypothyroid (1.8 microns/day) than in untreated rats (2.5 microns/day) (P < 0.01). The respective labeling indices 1 hr after labeling were 0.9% and 1.24% (P < 0.05). We conclude that hypothyroidism diminishes hepatocyte and littoral cell turnover and slows down their streaming.

  5. Angiotensin stimulates respiration in spontaneously hypertensive rats.

    PubMed

    Jennings, D B; Lockett, H J

    2000-05-01

    Spontaneously hypertensive rats (SHR) have an activated brain angiotensin system. We hypothesized 1) that ventilation (V) would be greater in conscious SHR than in control Wistar-Kyoto (WKY) rats and 2) that intravenous infusion of the ANG II-receptor blocker saralasin would depress respiration in SHR, but not in WKY. Respiration and oxygen consumption (VO(2)) were measured in conscious aged-matched groups (n = 16) of adult female SHR and WKY. For protocol 1, rats were habituated to a plethysmograph and measurements obtained over 60-75 min. After installation of chronic intravenous catheters, protocol 2 consisted of 30 min of saline infusion ( approximately 14 microliter. kg(-1). min(-1)) followed by 40 min of saralasin (1.3 microgram. kg(-1). min(-1)). V, tidal volume (VT), inspiratory flow [VT/inspiratory time (TI)], breath expiratory time, and VO(2) were higher, and breath TI was lower in "continuously quiet" SHR. In SHR, but not in WKY rats, ANG II-receptor block decreased V, VT, and VT/TI and increased breath TI. During ANG II-receptor block, an average decrease in VO(2) in SHR was not significant. About one-half of the higher V in SHR appears to be accounted for by an ANG II mechanism acting either via peripheral arterial receptors or circumventricular organs.

  6. Microvascular effects of copper deficiency in rats

    SciTech Connect

    Schuschke, D.A.; Saari, J.T.; Ackermann, D.M.; Miller, F.N. )

    1989-02-15

    We have studied the microcirculatory responses in copper deficient rats using the rat cremaster muscle preparation. Male Sprague-Dawley rats were fed either a copper supplemented diet (CuS, 5 ppm) or a copper deficient diet (CuD, O ppm) for five weeks prior to experimentation. The rats (240-300g) were anesthetized with pentobarbital and the cremaster (with intact nerve and blood supply) were spread in a tissue bath filled with krebs solution. In vivo television microscopy was used to observe the microcirculation. Fluorescein isothiocyanate tagged to bovine serum albumin (FITC-BSA) was injected i.a. 30 min prior to the start of experimentation. In the CuS animals photoactivation of the intravascular FITC-BSA caused significant platelet aggregation and reduction in red blood cell column diameter (RBCCD) by 30 min and stasis of flow by 60 min. In CuD animals there was no reduction in RBCCD and only minor platelet aggregation after 60 min of photoactivation. Topical administration of compound 48/80 (1.0 and 10.0 {mu}g/ml) induced a significantly greater macromolecular leakage (increased interstitial fluorescence of FITC-BSA) in the CuD animals than in the control, CuS animals. These results suggest that copper deficiency results in marked alterations of the regulatory mechanisms governing thrombosis and inflammation.

  7. Helminth parasites in black rats (Rattus rattus) and brown rats (Rattus norvegicus) from different environments in the Netherlands

    PubMed Central

    Franssen, Frits; Swart, Arno; van Knapen, Frans; van der Giessen, Joke

    2016-01-01

    Background Rattus norvegicus (brown rat) and Rattus rattus (black rat) are known carriers of bacteria, viruses, and parasites of zoonotic and veterinary importance. Moreover, rats may play a role in the transmission of muscle larvae of the zoonotic nematode Trichinella spiralis to farm animals. We aimed to study the intestinal and intramuscular helminths in wild rats from three different environments to assess the relevance of rats as carrier of zoonotic parasites for public health. Materials and methods Wild brown rats (117 individuals) and black rats (44 individuals) were captured at farms, in suburban and in rural environments in the Netherlands. Intestinal helminths were isolated and identified morphologically. Artificial digestion was used to isolate muscle larvae. Results and discussion Morphological analysis of rat intestinal contents yielded six nematode species (Syphacia muris, Heterakis spumosa, Aonchotheca murissylvatici, Trichuris muris, Nippostrongylus brasiliensis, and Strongyloides sp.), three cestode species (Hymenolepis diminuta, H. nana and Hymenolepis (=Rodentolepis) fraterna), and four trematode species (Plagiorchis muris, Plagiorchis proximus, Echinostoma chloropodis, and Notocotylus imbricatus). Black rats at farms displayed the lowest intestinal helminth species variation (six species) and carried overall on average 0.93 species simultaneously. In comparison, brown rats at farms carried seven helminth species and 1.91 species simultaneously. Brown rats from suburban environments displayed the highest species variation (11 species) at 1.82 simultaneous helminth species. Absence of trematodes from rats at farms may suggest limited exchange of rats between farms and surrounding wet rural environments. We report four species of veterinary (Syphacia muris) or zoonotic relevance (Hymenolepis diminuta, Hymenolepis nana and Plagiorchis muris). We did not find Trichinella muscle larvae, consistent with long-term prevalence in Dutch wild rats. PMID

  8. Ontogeny of the rat hepatic adrenoceptors

    SciTech Connect

    McMillian, M.K.

    1985-01-01

    Hepatic alpha-1, alpha-2, and beta-2 adrenoceptors were characterized during development of the rat through Scatchard analysis of (/sup 3/H)-prazosin, (/sup 3/H)-rauwolscine and (/sup 125/I)-pindolol binding to washed particle membrane preparations. Major changes in adrenoceptor number occur shortly before birth and at weaning. The fetal rat liver is characterized by a large number of alpha-2 adrenoceptors which falls 10-20 fold at birth. The number of hepatic beta adrenoceptors decreases 30-50% during the third week after birth increases slightly at weaning, then decreases gradually in the adult. Hepatic alpha-1 adrenoceptor number increases 3-5 fold at weaning to become the predominant adrenoceptor in the adult rat liver. The basis for the fall in alpha-2 number at birth remains unclear. The fall in beta receptor number at the end of the second week post-natally appears dependent on increased insulin and corticosterone secretion as well as increased NE release form nerve terminals. The basis for the increase in beta number at weaning and the sex-dependent loss of beta function but not receptor number in the adult rat remains unknown. The dramatic increases in alpha-1 number and function at weaning are dependent on increased adrenocortical secretion, adrenalectomy prevents the normal. This effect of adrenocorticoids might be mediated through glycogen, as glycogen depletion during fasting decreases alpha-1 receptor number and function at weaning are dependent on increased adrenocortical secretion, adrenalectomy prevents the normal. This effect of adrenocorticoids might be mediated through glycogen, as glycogen depletion during fasting decreases alpha-1 receptor number and function. These findings suggest that hepatic adrenoceptor number adapts from the low carbohydrate diet of the suckling rat to the high carbohydrate diet of the adult at weaning.

  9. Revisiting the supratrigeminal nucleus in the rat.

    PubMed

    Fujio, T; Sato, F; Tachibana, Y; Kato, T; Tomita, A; Higashiyama, K; Ono, T; Maeda, Y; Yoshida, A

    2016-06-01

    The supratrigeminal nucleus (Vsup), originally proposed as a premotoneuron pool in the trigeminal reflex arc, is a key structure of jaw movement control. Surprisingly, however, the location of the rat Vsup has not precisely been defined. In light of our previous cat studies, we made two hypotheses regarding the rat Vsup: (1) the Vsup is cytoarchitectonically distinguishable from its surrounding structures; (2) the Vsup receives central axon terminals of the trigeminal mesencephalic nucleus (Vmes) neurons which are primary afferents innervating muscle spindles of jaw-closing muscles and periodontal ligaments around the teeth. To test the first hypothesis, we examined the cytoarchitecture of the rat Vsup. The Vsup was identified as an area medially adjacent to the dorsomedial part of trigeminal principal sensory nucleus (Vp), and extended from the level just rostral to the caudal two-thirds of the trigeminal motor nucleus (Vmo) to the level approximately 150 μm caudal to the Vmo. Our rat Vsup was much smaller and its location was considerably different in comparison to the Vsup reported previously. To evaluate the second hypothesis, we tested the distribution patterns of Vmes primary afferent terminals in the cytoarchitectonically identified Vsup. After transganglionic tracer applications to the masseter, deep temporal, and medial pterygoid nerves, a large number of axon terminals were observed in all parts of Vsup (especially in its medial part). After applications to the inferior alveolar, infraorbital, and lingual nerves, a small number of axon terminals were labeled in the caudolateral Vsup. The Vsup could also be identified electrophysiologically. After electrical stimulation of the masseter nerve, evoked potentials with slow negative component were isolated only in the Vsup. The present findings suggest that the rat Vsup can be cytoarchitectonically and electrophysiologically identified, receives somatotopic termination of the trigeminal primary afferents, and

  10. Acetaminophen Induces Apoptosis in Rat Cortical Neurons

    PubMed Central

    Posadas, Inmaculada; Santos, Pablo; Blanco, Almudena; Muñoz-Fernández, Maríangeles; Ceña, Valentín

    2010-01-01

    Background Acetaminophen (AAP) is widely prescribed for treatment of mild pain and fever in western countries. It is generally considered a safe drug and the most frequently reported adverse effect associated with acetaminophen is hepatotoxicity, which generally occurs after acute overdose. During AAP overdose, encephalopathy might develop and contribute to morbidity and mortality. Our hypothesis is that AAP causes direct neuronal toxicity contributing to the general AAP toxicity syndrome. Methodology/Principal Findings We report that AAP causes direct toxicity on rat cortical neurons both in vitro and in vivo as measured by LDH release. We have found that AAP causes concentration-dependent neuronal death in vitro at concentrations (1 and 2 mM) that are reached in human plasma during AAP overdose, and that are also reached in the cerebrospinal fluid of rats for 3 hours following i.p injection of AAP doses (250 and 500 mg/Kg) that are below those required to induce acute hepatic failure in rats. AAP also increases both neuronal cytochrome P450 isoform CYP2E1 enzymatic activity and protein levels as determined by Western blot, leading to neuronal death through mitochondrial–mediated mechanisms that involve cytochrome c release and caspase 3 activation. In addition, in vivo experiments show that i.p. AAP (250 and 500 mg/Kg) injection induces neuronal death in the rat cortex as measured by TUNEL, validating the in vitro data. Conclusions/Significance The data presented here establish, for the first time, a direct neurotoxic action by AAP both in vivo and in vitro in rats at doses below those required to produce hepatotoxicity and suggest that this neurotoxicity might be involved in the general toxic syndrome observed during patient APP overdose and, possibly, also when AAP doses in the upper dosing schedule are used, especially if other risk factors (moderate drinking, fasting, nutritional impairment) are present. PMID:21170329

  11. Thalidomide affects the skeletal system of ovariectomized rats.

    PubMed

    Kaczmarczyk-Sedlak, Ilona; Folwarczna, Joanna; Trzeciak, Henryk I

    2009-01-01

    Apart from having written an inglorious chapter in the history of medicine, thalidomide is currently being intensely studied because of its multidimensional activity. The aim of this study was to examine the effects of thalidomide on the skeletal system in ovariectomized and non-ovariectomized rats. The experiments were carried out with female Wistar rats, divided into eight groups: sham-operated control rats; sham-operated rats receiving thalidomide at doses of 15, 30 or 60 mg/kg, po; ovariectomized control rats; ovariectomized rats receiving thalidomide at doses of 15, 30 or 60 mg/kg, po. The drug was administered for 4 weeks. Body mass gain and the mass of the uterus, liver, spleen and thymus were studied. Macrometric parameters and content of mineral substances, calcium and phosphorus in the femur, tibia and L-4 vertebra and histomorphometric parameters of the femur and tibia were examined. In the femur, the mechanical properties of the whole bone and of the femoral neck were examined. Thalidomide did not affect the skeletal system of the non-ovariectomized rats. Bilateral ovariectomy induced osteoporotic skeletal changes in mature female rats. The effects of thalidomide on the skeletal system of ovariectomized rats depended on the dose used. With a dose of 15 mg/kg, po, thalidomide counteracted some osteoporotic changes induced by estrogen deficiency. With a dose of 60 mg/kg, po, thalidomide intensified the destructive effects of estrogen deficiency on the rat skeletal system.

  12. Movements of exploration intact in rats with hippocampal lesions.

    PubMed

    Clark, Benjamin J; Hines, Dustin J; Hamilton, Derek A; Whishaw, Ian Q

    2005-08-30

    Prompted by the theoretical prediction that damage to the hippocampus should abolish exploratory behavior, the present study examined exploratory movements in control rats and rats with hippocampal lesions produced with the neurotoxin N-methyl d-aspartate (NMDA). In four daily 30-min sessions, control and hippocampal rats were exposed to an open circular table under room lighting. Both control and hippocampal rats spent a majority of time near, and organized trips away from, a portion of the table (home base) near a large cue placed proximal to the table. On Day 1, control and HPC rats made equal numbers of head orientations and a comparable number of trips, featuring equal travel distance and numbers of stops. By Day 4, dwell times near the home base increased and other movements decreased in the control rats but the activity profile of Day 1 persisted in the hippocampal rats. The high degree of similarity in behavior between hippocampal and control rats on Day 1 and the persistence of this behavior in hippocampal rats on Day 4 suggests that the hippocampus is not necessary for the display of normal exploratory movements per se. The absence of habituation of exploration in hippocampal rats is discussed in relation to contemporary theories of hippocampal function.

  13. Aging and regenerative capacity of skeletal muscle in rats.

    PubMed

    Kaasik, Priit; Aru, Maire; Alev, Karin; Seene, Teet

    2012-07-01

    The objective of the study was to examine skeletal muscle regeneration capacity of young and very old rats during autotransplantation. In 3.5 and 30 month-old Wistar rats, gastrocnemius muscle was removed and grafted back to its original bed. Incorporation of 3H leucine into myofibrillar and sarcoplasmic protein fractions, their relative contents in autografts and synthesis rate of MyHC and actin were recorded. The relative muscle mass of old rats was about 67% of that of young rats; the absolute mass of autografted muscle was 61% intact in the young rat group and 51% in the old rat group. Content of myofibrillar protein in the autografts of young rats was 46% of the intact muscle content, and 39% in the old rat group. In conclusion, the difference in skeletal muscle regeneration capacity of young and very old rats is about ten percent. In the autografts of both young and old rats, the regeneration of the contractile apparatus is less effective in comparison with the sarcoplasmic compartment.

  14. Genetic analyses of fancy rat-derived mutations.

    PubMed

    Kuramoto, Takashi; Yokoe, Mayuko; Yagasaki, Kayoko; Kawaguchi, Tatsuya; Kumafuji, Kenta; Serikawa, Tadao

    2010-01-01

    To collect rat mutations and increase the value of the rat model system, we introduced fancy-derived mutations to the laboratory and carried out genetic analyses. Six fancy rats were shipped from a fancy rat colony in the USA and used as founders. After initial crosses with a laboratory strain, TM/Kyo or PVG/Seac, inbreeding started and 6 partially inbred lines, including 2 sublines, were produced as Kyoto Fancy Rat Stock (KFRS) strains. During inbreeding, we isolated 9 mutations: 5 coat colors, American mink (am), Black eye (Be), grey (g), Pearl (Pel), siamese (sia); 1 coat pattern, head spot (hs); 2 coat textures, Rex (Re), satin (sat); and an ear pinnae malformation, dumbo (dmbo). Genetic analyses mapped 7 mutations to particular regions of the rat chromosomes (Chr): am to Chr 1, sia to Chr 1, sat to Chr 3, Re to Chr 7, g to Chr 8, dmbo to Chr 14, and hs to Chr 15. Candidate gene analysis revealed that a missense mutation in the tyrosinase gene, Ser79Pro, was responsible for sia. From mutant phenotypes and mapping positions, it is likely that all mutations isolated in this study were unique to the fancy rat. These findings suggest that fancy rat colonies are a good source for collecting rat mutations. The fancy-derived mutations, made available to biomedical research in the current study, will increase the scientific value of laboratory rats. PMID:20484848

  15. [Simvastatin's effect on insulin resistance in rats with diabetes mellitus].

    PubMed

    Iskakova, S; Zharmakhanova, G; Bekmukhambetov, Y; Dworacka, M; Dworacki, G

    2015-05-01

    The aim of this experimental study was to estimate the effect of Simvastatin on glycemic variability-related insulin resistance in the course of diabetes mellitus (DM) in rats. Fifty seven male Wistar rats were divided into four groups: I - rats with diabetes mellitus and glycemic variability treated with Simvastatin (20 mg/kg body weight, intragastral during 8 weeks); II - placebo-treated rats with DM and glycemic variability; III - placebo treated rats with DM and IV - nondiabetic control rats. DM was induced by feeding rats with high-fat diet (61%) during five weeks and low-dose of Streptozotocin (30 mg/kg, intraperitoneally). Daily glucose excursions were stimulated by feeding animals twice a day. We measured fasting blood glucose, glycated hemoglobin (HbA1c), insulin and HOMAIR was calculated. Higher insulin resistance in diabetic rats is related to greater daily glycemic variability. In our study was installed significant increasing HOMAIR in diabetics rats with glycemic excursions comparison with the control. Our results showed that the simvastatin-treatment decreases the indices glycemic variability and HOMA in diabetic rats with glycemic excursions.

  16. Genetic analyses of fancy rat-derived mutations.

    PubMed

    Kuramoto, Takashi; Yokoe, Mayuko; Yagasaki, Kayoko; Kawaguchi, Tatsuya; Kumafuji, Kenta; Serikawa, Tadao

    2010-01-01

    To collect rat mutations and increase the value of the rat model system, we introduced fancy-derived mutations to the laboratory and carried out genetic analyses. Six fancy rats were shipped from a fancy rat colony in the USA and used as founders. After initial crosses with a laboratory strain, TM/Kyo or PVG/Seac, inbreeding started and 6 partially inbred lines, including 2 sublines, were produced as Kyoto Fancy Rat Stock (KFRS) strains. During inbreeding, we isolated 9 mutations: 5 coat colors, American mink (am), Black eye (Be), grey (g), Pearl (Pel), siamese (sia); 1 coat pattern, head spot (hs); 2 coat textures, Rex (Re), satin (sat); and an ear pinnae malformation, dumbo (dmbo). Genetic analyses mapped 7 mutations to particular regions of the rat chromosomes (Chr): am to Chr 1, sia to Chr 1, sat to Chr 3, Re to Chr 7, g to Chr 8, dmbo to Chr 14, and hs to Chr 15. Candidate gene analysis revealed that a missense mutation in the tyrosinase gene, Ser79Pro, was responsible for sia. From mutant phenotypes and mapping positions, it is likely that all mutations isolated in this study were unique to the fancy rat. These findings suggest that fancy rat colonies are a good source for collecting rat mutations. The fancy-derived mutations, made available to biomedical research in the current study, will increase the scientific value of laboratory rats.

  17. Genetic study of host factors in gastrocarcinogenesis in rats.

    PubMed

    Morino, K; Ohgaki, H; Matsukura, N; Kawachi, T; Sugimura, T

    1982-01-01

    The effects of genetic factors on gastrocarcinogenesis in rats were studied by giving 83 micrograms/ml of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in the drinking-water to ACI strain rats, Buffalo strain rats, and their F1 hybrid rats for eight months. Animals were sacrificed on the 505th experimental day and examined histologically. The incidences of gastric carcinoma were as follows (no. of carcinoma-bearing rats/no. of effective animals): ACI rats, 86% (12/14) of males and 53% (9/17) of females; Buffalo rats, 19% (3/16) of males and 0% (0/13) of females; F1 hybrids between ACI and Buffalo rats, 23% (7/30) of males and 3% (1/32) of females. The incidence of gastric carcinoma in F1 hybrids was significantly lower than that in ACI rats but not significantly different from that in Buffalo rats. These results suggest that resistance to gastrocarcinogenesis by MNNG is an autosomally dominant trait.

  18. Metabolic responses to head-down suspension in hypophysectomized rats

    NASA Technical Reports Server (NTRS)

    Woodman, C. R.; Tipton, C. M.; Evans, J.; Linderman, J. K.; Gosselink, K.; Grindeland, R. E.

    1993-01-01

    Rats exposed to head-down suspension (HDS) exhibit reductions in maximal O2 consumption (VO2max) and atrophy of select hindlimb muscles. This study tested the hypothesis that an endocrine-deficient rat exposed to HDS would not exhibit reductions in VO2max or hindlimb muscle mass. Hypophysectomized (HYPX) and sham-operated (SHAM) rats were tested for VO2max before and after 28 days of HDS or cage control (CC) conditions. No significant reductions in VO2max were observed in HYPX rats. In contrast, SHAM-HDS rats exhibited a significant reduction in absolute (-16%) and relative (-29%) measures of aerobic capacity. Time course experiments revealed a reduction in VO2max in SHAM-HDS rats within 7 days, suggesting that cardiovascular adjustments to HDS occurred in the 1st wk. HDS was associated with atrophy of the soleus (-42%) in SHAM rats, whereas HYPX rats exhibited atrophy of the soleus (-36%) and plantaris (-13%). SHAM-HDS rats had significantly lower (-38%) soleus citrate synthase activities per gram muscle mass than SHAM-CC, but no significant differences existed between HYPX-HDS and -CC rats. HDS rats had an impaired ability to thermoregulate, as indicated by significantly greater temperature increases per unit run time, compared with their CC counterparts. Pretreatment plasma epinephrine levels were significantly lower in HYPX than in SHAM rats. Norepinephrine concentration was similar for all groups except HYPX-HDS, in which it was significantly higher. HDS had no significant effect on thyroxine or triiodothyronine. SHAM-HDS rats had significantly lower concentrations of testosterone and growth hormone.(ABSTRACT TRUNCATED AT 250 WORDS).

  19. Study of the effects of ozone in emphysematous rats

    SciTech Connect

    Dormans, J.A.; van Bree, L.; Boere, A.J.; Marra, M.; Rombout, P.J.

    1989-01-01

    The effects of short-term exposure to ozone on control and elastase-induced emphysematous rats were examined to investigate whether emphysema would change the pulmonary susceptibility to oxidant air pollution. Emphysema was induced in rats after a single intratracheal instillation of 0.2 IU elastase/g body weight. Histologically, panacinar emphysema was apparent at 2, 4, 8, and 16 wk, that is, the total duration of the experiment. The diagnosis was confirmed by morphometry: the mean linear intercepts (MLI) of elastase-treated rats were significantly increased at all observation times, whereas the internal surface areas (ISA) of the elastase-treated rats were significantly decreased. In addition, pulmonary function tests provided supportive evidence for the diagnosis of emphysema. Respiratory system compliance and functional residual capacity showed a significant increase in elastase-treated rats. No differences in inspiratory capacity or in forced vital capacity between control rats and elastase-treated rats were observed. The above data are indicative for a rat model for elastase-induced emphysema. Short-term exposure to ozone of elastase-treated rats revealed panacinar emphysema, including an inflammatory response in the centroacinar region. No differences in MLI as well as in ISA between ozone-exposed rats (with or without emphysema) and their respective controls were observed. Short-term exposure to ozone induced an identical, significant increase in protein content, lactate dehydrogenase, glucose-6-phosphate dehydrogenase, and glutathione peroxidase activities in lungs of normal and emphysematous rats. Moreover, these results strongly suggest that emphysematous rats are not more susceptible to ozone than nonemphysematous rats.

  20. Dysfunctional play and dopamine physiology in the Fischer 344 rat

    PubMed Central

    Siviy, Stephen M.; Crawford, Cynthia A.; Akopian, Garnik; Walsh, John P.

    2011-01-01

    Juvenile Fischer 344 rats are known to be less playful than other inbred strains, although the neurobiological substrate(s) responsible for this phenotype is uncertain. In the present study, Fischer 344 rats were compared to the commonly used outbred Sprague-Dawley strain on several behavioral and physiological parameters in order to ascertain whether the lack of play may be related to compromised activity of brain dopamine (DA) systems. As expected, Fischer 344 rats were far less playful than Sprague-Dawley rats, with Fischer 344 rats less likely to initiate playful contacts with a playful partner and less likely to respond playfully to these contacts. We also found that Fischer 344 rats showed less of a startle response and greater pre-pulse inhibition (PPI), especially at higher pre-pulse intensities. The increase in PPI seen in the Fischer 344 rat could be due to reduced DA modulation of sensorimotor gating and neurochemical measures were consistent with Fischer 344 rats releasing less DA than Sprague-Dawley rats. Fast scan cyclic voltammetry (FSCV) revealed Fischer 344 rats had less evoked DA release in dorsal and ventral striatal brain slices and high-performance liquid chromatography revealed Fischer 344 rats to have less DA turnover in the striatum and prefrontal cortex. We also found DA-dependent forms of cortical plasticity were deficient in the striatum and prefrontal cortex of the Fischer 344 rat. Taken together, these data indicate that deficits in play and enhanced PPI of Fischer 344 rats may be due to reduced DA modulation of corticostriatal and mesolimbic/mesocortical circuits critical to the execution of these behaviors. PMID:21335036

  1. Urine from stressed rats increases immobility in receptor rats forced to swim: role of 2-heptanone.

    PubMed

    Gutiérrez-García, Ana G; Contreras, Carlos M; Mendoza-López, M Remedios; García-Barradas, Oscar; Cruz-Sánchez, J Samuel

    2007-05-16

    The present study was aimed to determine whether the urine from donor rats, which were physically stressed (UD-PS) by unavoidable electric footshocks, produces despair in receptor partner rats (RP) in the long-term. For each trial, an RP rat was placed during 10 min once per day for 21 days in a small non-movement-restricting cage impregnated with the urine collected from a UD-PS rat. Control rats, free of stimulation, maintained their locomotion and immobility scores at basal values throughout the 21-day test. After 21 days of stressing experience [F(2,90)=15.22, P<0.0001] locomotion significantly increased in RP rats (r=0.938, P<0.01), whereas in the UD-PS group locomotion decreased (r=-0.606, P<0.05). The RP and UD-PS groups displayed the longest time of immobility [F(2,90)=8.83, P<0.001] in the forced-swim test (RP, r=0.886, P<0.05; UD-PS, r=0.962, P<0.001) compared with the control group (r=-0.307, NS). We conclude that the RP became similarly despaired as the UD-PS group through the action of 2-heptanone, a ketonic compound identified in UD-PS urine by HS-GC/MS techniques. This ketone was found to be increased [F(2,15)=3.50, P<0.05] from the 1st day of unavoidable electric footshocks, and to induce despair, an effect reverted [F(2,21)=16.5, P<0.0001] by imipramine (5.0 mg/kg) in another group of rats.

  2. A Low-Protein Diet Enhances Angiotensin II Production in the Lung of Pregnant Rats but Not Nonpregnant Rats

    PubMed Central

    Gao, Haijun; Tanchico, Daren Tubianosa; Yallampalli, Uma; Yallampalli, Chandrasekhar

    2016-01-01

    Pulmonary angiotensin II production is enhanced in pregnant rats fed a low-protein (LP) diet. Here we assessed if LP diet induces elevations in angiotensin II production in nonpregnant rats and whether Ace expression and ACE activity in lungs are increased. Nonpregnant rats were fed a normal (CT) or LP diet for 8, 12, or 17 days and timed pregnant rats fed for 17 days from Day 3 of pregnancy. Plasma angiotensin II, expressions of Ace and Ace2, and activities of these proteins in lungs, kidneys, and plasma were measured. These parameters were compared among nonpregnant rats or between nonpregnant and pregnant rats fed different diets. Major findings are as follows: (1) plasma angiotensin II levels were slightly higher in the LP than CT group on Days 8 and 12 in nonpregnant rats; (2) expression of Ace and Ace2 and abundance and activities of ACE and ACE2 in lungs, kidneys, and plasma of nonpregnant rats were unchanged by LP diet except for minor changes; (3) the abundance and activities of ACE in lungs of pregnant rats fed LP diet were greater than nonpregnant rats, while those of ACE2 were decreased. These results indicate that LP diet-induced increase in pulmonary angiotensin II production depends on pregnancy. PMID:27195150

  3. Generation and characterization of rat liver stem cell lines and their engraftment in a rat model of liver failure

    PubMed Central

    Kuijk, Ewart W.; Rasmussen, Shauna; Blokzijl, Francis; Huch, Meritxell; Gehart, Helmuth; Toonen, Pim; Begthel, Harry; Clevers, Hans; Geurts, Aron M.; Cuppen, Edwin

    2016-01-01

    The rat is an important model for liver regeneration. However, there is no in vitro culture system that can capture the massive proliferation that can be observed after partial hepatectomy in rats. We here describe the generation of rat liver stem cell lines. Rat liver stem cells, which grow as cystic organoids, were characterized by high expression of the stem cell marker Lgr5, by the expression of liver progenitor and duct markers, and by low expression of hepatocyte markers, oval cell markers, and stellate cell markers. Prolonged cultures of rat liver organoids depended on high levels of WNT-signalling and the inhibition of BMP-signaling. Upon transplantation of clonal lines to a Fah−/− Il2rg−/− rat model of liver failure, the rat liver stem cells engrafted into the host liver where they differentiated into areas with FAH and Albumin positive hepatocytes. Rat liver stem cell lines hold potential as consistent reliable cell sources for pharmacological, toxicological or metabolic studies. In addition, rat liver stem cell lines may contribute to the development of regenerative medicine in liver disease. To our knowledge, the here described liver stem cell lines represent the first organoid culture system in the rat. PMID:26915950

  4. The local effect of octreotide on mechanical pain sensitivity is more sensitive in DA rats than DA.1U rats.

    PubMed

    Yao, Fan-Rong; Wang, Hui-Sheng; Guo, Yuan; Zhao, Yan

    2016-02-01

    A recent study by the authors indicated that major histocompatibility complex (MHC) genes are associated with the differences in basal pain sensitivity and in formalin model between Dark-Agouti (DA) and novel congenic DA.1U rats, which have the same genetic background as DA rats except for the u alleles of MHC. The objective of the present study is to investigate whether there is a difference in the pristane-induced arthritis (PIA) model and local analgesic effect of octreotide (OCT) between DA and DA.1U rats. The hindpaw mechanical withdrawal threshold (MWT) and heat withdrawal latency (HWL) were observed. The C unit firings of the tibial nerve evoked by non-noxious and noxious toe movements were recorded by electrophysiological methods in normal and PIA models in DA and DA.1U rats before and after local OCT administration. The expression of somatostatin receptor 2A (SSTR2A) was observed by immunohistochemistry. The results demonstrate that DA rats have a higher mechanical sensitivity than DA.1U rats after PIA. Local OCT administration significantly elevated MWT in DA rats under normal and PIA sate, but not in DA.1U rats. The electrophysiological experiments showed OCT significantly attenuated the firings of C units evoked by non-noxious and noxious stimulation in DA rats more than those in DA.1U rats both in normal and PIA states. In addition, the expression of SSTR2A in the dorsal horn of the spinal cord was significantly higher in DA than in DA.1U rats. All of the findings suggest a higher local analgesic effect of OCT in DA rats than DA.1U rats, which might be associated with the MHC genes.

  5. Maturation of rat proximal tubule chloride permeability.

    PubMed

    Baum, Michel; Quigley, Raymond

    2005-12-01

    We have previously shown that neonate rabbit tubules have a lower chloride permeability but comparable mannitol permeability compared with adult proximal tubules. The surprising finding of lower chloride permeability in neonate proximals compared with adults impacts net chloride transport in this segment, which reabsorbs 60% of the filtered chloride in adults. However, this maturational difference in chloride permeability may not be applicable to other species. The present in vitro microperfusion study directly examined the chloride and mannitol permeability using in vitro perfused rat proximal tubules during postnatal maturation. Whereas there was no maturational change in mannitol permeability, chloride permeability was 6.3 +/- 1.3 x 10(-5) cm/s in neonate rat proximal convoluted tubule and 16.1 +/- 2.3 x 10(-5) cm/s in adult rat proximal convoluted tubule (P < 0.01). There was also a maturational increase in chloride permeability in the rat proximal straight tubule (5.1 +/- 0.6 x 10(-5) cm/s vs. 9.3 +/- 0.6 x 10(-5) cm/s, P < 0.01). There was no maturational change in bicarbonate-to-chloride permeabilities (P(HCO3)/P(Cl)) in the rat proximal straight tubules (PST) and proximal convoluted tubules (PCT) or in the sodium-to-chloride permeability (P(Na)/P(Cl)) in the proximal straight tubule; however, there was a significant maturational decrease in proximal convoluted tubule P(Na)/P(Cl) with postnatal development (1.31 +/- 0.12 in neonates vs. 0.75 +/- 0.06 in adults, P < 0.001). There was no difference in the transepithelial resistance measured by current injection and cable analysis in the PCT, but there was a maturational decrease in the PST (7.2 +/- 0.8 vs. 4.6 +/- 0.1 ohms x cm2, P < 0.05). These studies demonstrate there are maturational changes in the rat paracellular pathway that impact net NaCl transport during development. PMID:16051720

  6. Diseases Transmitted by Man's Worst Friend: the Rat.

    PubMed

    Fox, James G

    2015-12-01

    Historically, the rat has been considered a scourge to mankind, for example, rats infected with the plague bacillus that caused the Black Death, which accounted for millions of deaths in Europe during the Middle Ages. At least three pandemics (in the 5th and 6th, 8th through 14th, and 19th through 21st centuries) of plague ravaged civilizations, and the disease undoubtedly plagued humankind prior to recorded history. Also, numerous other diseases are spread to humans by rats; thus, a quote from Hans Zinsser's text Rats, Lice, and History, "Man and rat will always be pitted against each other as implacable enemies," conveys the general revulsion that society holds for the wild rat. PMID:27337284

  7. Exploring phenotypic data at the rat genome database.

    PubMed

    Twigger, Simon N; S Smith, Jennifer; Zuniga-Meyer, Angela; Bromberg, Susan K

    2006-07-01

    The laboratory rat, Rattus norvegicus, is an important model of human health and disease, and experimental findings in the rat have direct relevance to human-based research. The Rat Genome Database (RGD, http://rgd.mcw.edu) is a model-organism database that provides access to wide variety of curated rat data such as genes and their homologs, quantitative trait loci, phenotypes, comparative mapping, and genome analysis. We present an overview of the database followed by specific examples that can be used to gain experience in employing RGD to explore the wealth of functional data available for the rat. We show how to make associations with the genome and use comparative tools to link the rat with human and mouse in order to integrate results from these three species of critical biomedical importance.

  8. Comparison of the blood coagulation profiles of ferrets and rats.

    PubMed

    Takahashi, Saya; Hirai, Norihiko; Shirai, Mitsuyuki; Ito, Katsuaki; Asai, Fumitoshi

    2011-07-01

    The aim of this study was to examine the blood coagulation profiles of ferrets and compare them with those of rats. The ferret activated partial thromboplastin time (aPTT) was slightly longer than the rat aPTT. In contrast, the ferret prothrombin time and thrombin time were profoundly shorter than the corresponding rat values. The fibrinogen level in ferret plasma was 2 times higher than that in rats. Heparin prolonged all blood coagulation times in a concentration-dependent manner in both ferret and rat plasma. A significantly (P<0.01) higher concentration of heparin was required to double the aPTT in ferrets than rats. These blood coagulation data for ferrets will be useful in experimental animal studies.

  9. Discriminative and reinforcing stimulus properties of music for rats.

    PubMed

    Otsuka, Y; Yanagi, J; Watanabe, S

    2009-02-01

    We trained rats to discriminate music by Bach from that by Stravinsky using operant conditioning. The rats successfully learned the discrimination and transferred their discrimination to novel music by the same artists. Then, we trained rats on concurrent-chain schedule in which the terminal links were associated with different music, Bach or Stravinsky. The rats did not show strong preference for either style of music, although one subject showed a preference for Bach and another subject preferred Stravinsky. Finally, we examined the validity of the concurrent-chain procedure as a method of preference measurement with conspecific vocalization evoked by an aversive experience. Most of the rats preferred white noise to the conspecific vocalization. Therefore, music has a discriminative stimulus property but not a clear reinforcing property for rats. PMID:19022358

  10. Hormonal modulation of tear volume in the rat.

    PubMed

    Sullivan, D A; Allansmith, M R

    1986-02-01

    The present study examined the influence of hormones on the tear volume of male rats. The mean tear volume in a population of 2-3-month-old intact rats equaled 4.6 +/- 0.2 microliter. This volume, however, varied depending upon the hormonal environment of the animal. Orchiectomy induced a significant, 46%, increase in the mean tear volume, compared with that of intact rats. Testosterone administration to orchiectomized rats reversed this increase and caused a significant reduction in tear volume. Of interest, this androgen action was prevented if rats were also hypophysectomized. Hypophysectomy alone decrease tear volume and this response was not influenced by later castration. Other endocrine manipulations, including thyroidectomy, adrenalectomy and estrogen treatment of orchiectomized rats had no effect on tear volume. Overall, our results indicate that tear volume may be modulated by hormones from the hypothalamic-pituitary-gonadal axis.

  11. Prevention of anemia alleviates heart hypertrophy in copper deficient rats

    SciTech Connect

    Lure, M.D.; Fields, M.; Lewis, C.G. Univ. of Maryland, College Park Georgetown Univ., Washington, DC )

    1991-03-11

    The present investigation was designed to examine the role of anemia in the cardiomegaly and myocardial pathology of copper deficiency. Weanling rats were fed a copper deficient diet containing either starch (ST) or fructose (FRU) for five weeks. Six rats consuming the FRU diet were intraperitoneally injected once a week with 1.0 ml/100g bw of packed red blood cells (RBC) obtained from copper deficient rats fed ST. FRU rats injected with RBC did not develop anemia. Additionally, none of the injected rats exhibited heart hypertrophy or gross pathology and all survived. In contrast, non-injected FRU rats were anemic, exhibited severe signs of copper deficiency which include heart hypertrophy with gross pathology, and 44% died. Maintaining the hematocrit with RBC injections resulted in normal heart histology and prevented the mortality associated with the fructose x copper interaction. The finding suggest that the anemia associated with copper deficiency contributes to heart pathology.

  12. Relationship of roof rat population indices with damage to sugarcane

    USGS Publications Warehouse

    Lefebvre, Lynn W.; Engeman, Richard M.; Decker, David G.; Holler, Nicholas R.

    1989-01-01

    Roof rats (Rattus rattus) cause substantial damage to sugarcane in South Florida (Samol 1972; Lefebvre et al. 1978, 1985). Accurate estimates of roof rat populations in sugarcane fields would be useful for determining when to to treat a field to control roof rats and for assessing the efficacy of control. However, previous studies have indicated that roof rats exhibit trap shyness, which makes capture-recapture population estimates difficult (Lefebvre et al. 1978, 1985; Holler et al., 1981). Until trapping methods are sufficiently improved to allow accurate population estimates, indices of population size that relate to damage need to be developed. The objectives of our study were to examine the relationship of several indices of roof rat populations to the percentage of sugarcane stalks damaged at harvest; to determine which population index would be most useful for sugarcane growers; and to report on a test of several types of live traps for roof rats.

  13. Taurine in the osmoregulation of the Brattleboro rat

    SciTech Connect

    Nieminen, M.J.; Tuomisto, L.; Solatunturi, E.; Eriksson, L.; Paasonen, M.K.

    1988-01-01

    The function of taurine in mammalian osmoregulation was studied in the Brattleboro rat with hereditary hypothalamic diabetes insipidus (DI). DI rats are chronically dehydrated because of their inability to synthesize vasopressin. One day of water deprivation did not affect the water balance in rats with normal vasopressin synthesis, whereas DI rats were markedly dehydrated and lost considerably body weight. Taurine content and /sup 3/H-taurine accumulation by platelets were significantly higher in DI rats, with a further increase after one day of water deprivation. In DI rats, water deprivation also evoked a clear taurine increase in skeletal muscle and in the brain. These findings indicate that taurine has an osmoregulatory function in mammals.

  14. Carboxyhemoglobin formation due to carbon monoxide exposure in rats

    SciTech Connect

    Benignus, V.A.; Annau, Z.

    1994-01-01

    The Coburn-Forster-Kane equation (CFKE) is a well tested model for prediction of COHb formation due to carbon monoxide (CO) exposure in humans. There have been few and relatively poorly tested attempts to implement a CFKE for rats. Such an implementation is of interest because many experiments on the effects of CO in rats were done without measuring COHb. To extrapolate from rats to humans requires a rat version of the CFKE. A CFKE was implemented for rats by using parameters found in the literature and estimating them from the data. It was deduced from the blood-gas data that rats hyperventilate slightly as COHb increases. The hyperventilation required an iterative solution to the CFKE. The iterative CFKE predictions were found to differ statistically from observations, but in explainable ways and/or in small amounts.

  15. Protein purification and cloning of diacylglycerol lipase from rat brain.

    PubMed

    Aso, Chizu; Araki, Mari; Ohshima, Noriyasu; Tatei, Kazuaki; Hirano, Tohko; Obinata, Hideru; Kishi, Mikiko; Kishimoto, Koji; Konishi, Akimitsu; Goto, Fumio; Sugimoto, Hiroyuki; Izumi, Takashi

    2016-06-01

    Diacylglycerol (DG) lipase, which hydrolyses 1-stearoyl-2-arachidonyl-sn-glycerol to produce an endocannabinoid, 2-arachidonoylglycerol, was purified from the soluble fraction of rat brain lysates. DG lipase was purified about 1,200-fold by a sequential column chromatographic procedure. Among proteins identified by mass spectrometry analysis in the partially purified DG lipase sample, only DDHD domain containing two (DDHD2), which was formerly regarded as a phospholipase A1, exhibited significant DG lipase activity. Rat DDHD2 expressed in Chinese hamster ovary cells showed similar enzymatic properties to partially purified DG lipase from rat brain. The source of DG lipase activity in rat brain was immunoprecipitated using anti-DDHD2 antibody. Thus, we concluded that the DG lipase activity in the soluble fraction of rat brain is derived from DDHD2. DDHD2 is distributed widely in the rat brain. Immunohistochemical analysis revealed that DDHD2 is expressed in hippocampal neurons, but not in glia.

  16. Spatial memory in the desert kangaroo rat (Dipodomys deserti).

    PubMed

    Langley, C M

    1994-03-01

    Desert kangaroo rats (Dipodomys deserti) forage for seed distributed in patches in the desert environment and may remember patch locations. In Experiment 1, 7 desert kangaroo rats that had discovered the location of a plastic token in 1 box accurately dug for a token hidden in the same location in a 2nd identical box. Results of Experiment 2 indicated that the rats primarily remembered the spatial location of the token within the box in relation to extramaze objects and the walls of the experimental box. Female rats also remembered the chip's location in relation to objects inside the box, but males did not. Experiment 3 demonstrated that the rats' ability to locate the buried token did not depend on detection of the odor of the token. In the discussion I propose that spatial memory in kangaroo rats may have evolved as a result of an overall change in the ontogeny of the species rather than as a specialized adaptation for foraging efficiency.

  17. Characterization of rat prothymocyte with monoclonal antibodies recognizing rat lymphocyte membrane antigenic determinants

    SciTech Connect

    Hale, M.L.; Greiner, D.L.; McCarthy, K.F.

    1987-01-01

    Utilizing the technique of fluorescence-activated cell sorting and monoclonal antibodies directed at rat membrane antigens, various subpopulations of Lewis bone marrow cells were isolated and subsequently transfused into sublethally irradiated, histocompatible NBr recipient rats by either intravenous of intrathymic inoculation. Recipient rats were sacrificed and cell suspensions from thymus and other lymphoid tissue were examined for the presence of the RT7.1 marker on Lewis thymus-derived lymphocytes by fluorescence-activated cell analysis. From these studies, the population of Lewis bone-marrow cells that could resonstitute T cells in the NBr rats was found to be Ox-22 negative, Ox-7 positive, W3/13 positive, and Ox-18 positive. Further analysis characterized the prothymocyte as being Ox-7 upper 20% positive and W3/13 weakly positive. In addition, this marrow-cell population was able to protect lethally irradiated Lewis rats (9.5 GY) in 30-day survival tests. These studies have indicated that the prothymocyte either has been derived from the Ox-22 negative, Ox-7 upper 20% positive, and W3/13 positive marrow cells or, like the hematopoietic stem cell, this cell has also been characterized by this phenotype.

  18. The occurrence of parathyroid hypertensive factor (PHF) in Dahl rats.

    PubMed

    Lewanczuk, R Z; Pang, P K

    1993-09-01

    Parathyroid hypertensive factor (PHF) is a newly described circulating hypertensive factor which is present in genetic hypertensive rat models, and which has been associated with salt sensitivity in essential hypertensive patients. To determine if Dahl-S or -R rats differentially express PHF-like activity, and whether such PHF levels might be affected by salt intake, we placed 5-week-old Dahl-S and Dahl-R rats on one of three diets: low salt (< 0.04%), normal salt (0.7%), or high salt (8%). After 8 weeks on the respective diets, mean arterial pressure was measured and plasma obtained for PHF analysis. Mean arterial pressures of Dahl-R rats were not different despite varying salt intakes. Mean arterial pressures of Dahl-S rats on normal and high salt diets, but not on the low salt diet, were significantly higher than those of Dahl-R rats on the same diet. PHF-like activity was not detectable in Dahl-R rats at any level of salt intake. In Dahl-S rats, no PHF activity was detectable in rats on the low salt diet, but in rats on the normal and high salt diets, significant PHF-like activity was detectable (9.5 +/- 2 mm Hg and 14.2 +/- 2 mm Hg, respectively, P < .001 in both cases). For all Dahl-S rats together, PHF levels correlated with mean arterial pressure (r = 0.50, P = .0077). These results show that Dahl-S rats are capable of expressing PHF-like activity, which is induced by increasing dietary salt intakes.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Mutagenicity of comfrey (Symphytum Officinale) in rat liver.

    PubMed

    Mei, N; Guo, L; Fu, P P; Heflich, R H; Chen, T

    2005-03-14

    Comfrey is a rat liver toxin and carcinogen that has been used as a vegetable and herbal remedy by humans. In order to evaluate the mechanisms underlying its carcinogenicity, we examined the mutagenicity of comfrey in the transgenic Big Blue rat model. Our results indicate that comfrey is mutagenic in rat liver and the types of mutations induced by comfrey suggest that its tumorigenicity results from the genotoxicity of pyrrolizidine alkaloids in the plant. PMID:15726100

  20. The oncogenic action of ionizing radiation on rat skin

    SciTech Connect

    Burns, F.J.; Garte, S.J.

    1990-01-01

    An extensive experiment involving approximately 400 rats exposed to the neon ion beam at the Bevalac in Berkeley, CA and to electrons is nearing completion. Progress is described in three areas corresponding to the specific aims of the proposal: (1) carcinogenesis and DNA strand breaks in rat skin following exposure by the neon ions or electrons; (2) oncogene activation in radiation-induced rat skin cancers; (3) DNA strand breaks in the epidermis as a function of radiation penetration. 59 refs., 4 tabs.

  1. Rapid avoidance acquisition in Wistar-Kyoto rats.

    PubMed

    Servatius, R J; Jiao, X; Beck, K D; Pang, K C H; Minor, T R

    2008-10-10

    The relationship between trait stress-sensitivity, avoidance acquisition and perseveration of avoidance was examined using male Wistar-Kyoto (WKY) and Sprague-Dawley (SD) rats. Behavior in an open field was measured prior to escape/avoidance (E/A) acquisition and extinction. E/A was assessed in a discrete trial lever-press protocol. The signal-shock interval was 60s with subsequent shocks delivered every 3s until a lever-press occurred. A 3-min flashing light safety signal was delivered contingent upon a lever-press (or failure to respond in 5 min). WKY rats displayed phenotypic low open field activity, but were clearly superior to SD rats in E/A performance. As avoidance responses were acquired and reached asymptotic performance, SD rats exhibited "warm up", that is, SD rats rarely made avoidance responses on the initial trial of a session, even though later trials were consistently accompanied with avoidance responses. In contrast, WKY rats did not show the "warm up" pattern and avoided on nearly all trials of a session including the initial trial. In addition to the superior acquisition of E/A, WKY rats demonstrated several other avoidance features that were different from SD rats. Although the rates of nonreinforced intertrial responses (ITRs) were relatively low and selective to the early safety period, WKY displayed more ITRs than SD rats. With removal of the shocks extinction was delayed in WKY rats, likely reflecting their nearly perfect avoidance performance. Even after extensive extinction, first trial avoidance and ITRs were evident in WKY rats. Thus, WKY rats have a unique combination of trait behavioral inhibition (low open field activity and stress sensitivity) and superior avoidance acquisition and response perseveration making this strain a good model to understand anxiety disorders.

  2. Induction by degraded carrageenan of colorectal tumors in rats.

    PubMed

    Ashi, K W; Inagaki, T; Fujimoto, Y; Fukuda, Y

    1978-03-01

    Degraded carrageenan derived from the red seaweed Eucheuma spinosum was given to Sprague-Dawley rats through the diet, in drinking water or by stomach tube for up to 24 months. Carrageenan-induced squamous cell carcinomas, adenocarcinomas and adenomas in the colorectum were observed. Some rats had metastases to the regional lymph nodes of squamous cell carcinomas. These results show that degraded carrageenan is carcinogenic to the colorectum of the rat. PMID:647659

  3. Tail skin temperatures reflect coping styles in rats.

    PubMed

    Agren, Greta; Lund, Irene; Thiblin, Ingemar; Lundeberg, Thomas

    2009-02-16

    This study was carried out to elucidate the predictive value of tail skin temperatures (TSTs) assessed in naïve rats as a non-invasive pre-experimental method of classification of coping style. Male Lewis rats were classified according to tail skin temperatures (TST), and relative size within cage-groups. TSTs were monitored over two-hour periods following exposure to physical and emotional stressors. Bodyweight-shifts associated to the experiments were analysed. Six organs of neuroendocrine relevance to allostasis were weighed. Challenge-specific TST-profiles were size-related and consistent with proactive or reactive coping. Pro-active (A) rats showed a more pronounced TST-response to unknown conspecifics, but reactive (B) rats to environmental novelties. B-rats showed challenge-specific weight-losses while A-rats gained more after experiments. Second size males showed rapidly decreased TSTs (vasoconstriction) after nociceptive stimulation. Males that showed the highest basal TSTs and weight-loss in emotionality tests had lost a first rank position during a pre-experimental period, suggesting long-lasting effects of social defeat. Pre-experimental growth correlated positively to adiposisity post-experimentally, but negatively to testes relative weight in B-rats. Scaling effects explained heart-size in B-rats and pituitary-size in A-rats. The overall patterns that emerged, in factor analyses including organ sizes, were consistent with pro-active coping in A-rats and reactive in B-rats. Our results, controlling for rank-effects, suggest that non-invasively assessed TSTs may predict individual stress-coping phenotypes pre-experimentally in rats housed in groups. PMID:19041659

  4. Oxidative stress in normal and diabetic rats.

    PubMed

    Torres, M D; Canal, J R; Pérez, C

    1999-01-01

    Parameters related to oxidative stress were studied in a group of 10 Wistar diabetic rats and 10 control rats. The levels of total erythrocyte catalase activity in the diabetic animals were significantly (p<0.001) greater than the control levels. The diabetic animals presented an amount of vitamin E far greater (p<0.0001) than the controls, as was also the case for the vitaminE/polyunsaturated fatty acid (PUFA) and vitaminE/linoleic acid (C18:2) ratios. Greater vitaminE/triglyceride (TG) ratio, however, appeared in the control group. The corresponding vitamin A ratios (vitaminA/TG, vitaminA/PUFA, vitaminA/C 18:2) were higher in the control group. Our work corroborates the findings that fatty acid metabolism presents alterations in the diabetes syndrome and that the antioxidant status is affected. PMID:10523056

  5. Metabolism of the stimulated rat spleen

    PubMed Central

    Mazur, Abraham

    1968-01-01

    Assay of the enzyme ferrochelatase in marrow, liver, spleen, and red cells has been employed to assess the extent of erythropoietic stimulation in animals bearing the Walker 256 carcinosarcoma and in rats treated by administration of phenylhydrazine, cobalt chloride, human urinary erythropoietin, or chronic blood loss. In all instances, the spleen sustains the most marked increase of ferrochelatase activity, per gram of tissue. Spleen erythropoietic activity stimulation was confirmed by quantitative measurements in respiring slices of 59Fe and 14C incorporation into hemoglobin and ferritin. Increased spleen ferrochelatase activity in cobalt chloride-treated rats is prevented by actinomycin D, indicating that stimulated synthesis of the enzyme is associated with the metabolism of RNA. PMID:5676519

  6. Extensive exchange of rat liver microsomal phospholipids.

    PubMed

    Zilversmit, D B; Hughes, M E

    1977-08-15

    Liver microsomal fractions were prepared from rats injected with a single dose of choline [14C]methylchloride or with single or multiple doses of 32Pi. Exchangeability of microsomal phospholipids was determined by incubation with an excess of mitochondria and phospholipid exchange proteins derived from beef heart, beef liver or rat liver. Labeled phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine and phosphatidylinositol were found to act as a single pool and were 85--95% exchangeable in 1--2h. High latencies of mannose-6-phosphate phosphohydrolase activities and impermeability of microsomes to EDTA proved that phospholipid exchange proteins did not have access to the intracisternal space. If microsomal membranes are largely composed of phospholipid bilayers, the experiments suggest that one or more of the phospholipid classes in microsomal membranes undergo rapid translocation between the inner and outer portions of the bilayer.

  7. Influence of spaceflight on rat skeletal muscle

    NASA Technical Reports Server (NTRS)

    Martin, Thomas P.; Edgerton, V. Reggie; Grindeland, Richard E.

    1988-01-01

    The effect of a 7-day spaceflight (aboard NASA's SL-3) on the size and the metabolism of single fibers from several rat muscles was investigated along with the specificity of these responses as related to the muscle type and the size of fibers. It was found that the loss of mass after flight was varied from 36 percent in the soleus to 15 percent in the extensor digitorum longus. Results of histochemical analyses showed that the succinate dehydrogenase (SDH) activity in muscles of flight-exposed rats was maintained at the control levels, whereas the alpha-glycerol phosphate dehydrogenase (GPD) activity was either maintained or increased. The analyses of the metabolic profiles of ATPase, SDH, and GPD indicated that, in some muscles, there was an increase in the poportion of fast oxidative-glycolytic fibers.

  8. The disposition of quinfamide in the rat.

    PubMed

    Baker, J F; O'Melia, P E; Benziger, D P; Clemans, S D; Edelson, J

    1982-07-01

    The disposition of quinfamide 1-(dichloroacetyl)-6-(2-furoyloxy)-1, 2, 3, 4-tetrahydroquinoline, an enteric anti-amoebic agent, was studied in the rat. A peak blood level equivalent to 2.3 micrograms/ml of quinfamide was observed at 7 hr following a 20 mg/kg oral dose. Urinary recovery of radioactivity was much higher (84%) following intravenous than oral (48%) administration. Drug levels, in all of the tissues examined. were low. The major pathways of quinfamide metabolism in the rat involve hydrolysis of one or both ester groups, acetylation of the de-acylated product to 1-acetyl-1, 2, 3, 4-tetrahydro-6-quinolinol, oxidation of this to the 1-glycolyl metabolite, and aromatization to 6-hydroxyquinoline.

  9. Do rats represent time logarithmically or linearly?

    PubMed

    Yi, Linlin

    2009-06-01

    This study examined two possible psychophysical time scales, a logarithmic representation of time with constant variability and a linear representation of time with scalar variability. Twenty-four rats were tested on a modified temporal bisection procedure in which multiple responses could occur in a 10-s time window after the termination of a stimulus. The number of "long" or "short" responses was used as a measure of the rats' certainty of the duration of the presented interval. Data were analyzed with signal detection theory, and straight lines were fit to the zROC curves with the assumptions of a logarithmic representation of time with constant variability and a linear representation of time with scalar variability. The logarithmic representation of time with constant variability provided a better fit to the data than the linear representation of time with scalar variability.

  10. Extensive exchange of rat liver microsomal phospholipids.

    PubMed

    Zilversmit, D B; Hughes, M E

    1977-08-15

    Liver microsomal fractions were prepared from rats injected with a single dose of choline [14C]methylchloride or with single or multiple doses of 32Pi. Exchangeability of microsomal phospholipids was determined by incubation with an excess of mitochondria and phospholipid exchange proteins derived from beef heart, beef liver or rat liver. Labeled phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine and phosphatidylinositol were found to act as a single pool and were 85--95% exchangeable in 1--2h. High latencies of mannose-6-phosphate phosphohydrolase activities and impermeability of microsomes to EDTA proved that phospholipid exchange proteins did not have access to the intracisternal space. If microsomal membranes are largely composed of phospholipid bilayers, the experiments suggest that one or more of the phospholipid classes in microsomal membranes undergo rapid translocation between the inner and outer portions of the bilayer. PMID:889827

  11. Secretin: specific binding to rat brain membranes

    SciTech Connect

    Fremeau, R.T. Jr.; Jensen, R.T.; Charlton, C.G.; Miller, R.L.; O'Donohue, T.L.; Moody, T.W.

    1983-08-01

    The binding of (/sup 125/I)secretin to rat brain membranes was investigated. Radiolabeled secretin bound with high affinity (KD . 0.2 nM) to a single class of noninteracting sites. Binding was specific, saturable, and reversible. Regional distribution studies indicated that the specific binding was greatest in the cerebellum, intermediate in the cortex, thalamus, striatum, hippocampus, and hypothalamus, and lowest in the midbrain and medulla/pons. Pharmacological studies indicated that only secretin, but not other peptides, inhibits binding of (/sup 125/I)secretin with high affinity. Also, certain guanine nucleotides inhibited high affinity binding. These data indicate that rat brain membranes possess high affinity binding sites specific for secretin and that with the use of (/sup 125/I) secretin the kinetics, stoichiometry, specificity, and distribution of secretin receptors can be directly investigated.

  12. Decalcification of calcium polycarbophil in rats.

    PubMed

    Yamada, T; Saito, T; Takahara, E; Nagata, O; Tamai, I; Tsuji, A

    1997-03-01

    The in vivo decalcification of calcium polycarbophil was examined. The decalcification ratio of [45Ca]calcium polycarbophil in the stomach after oral dosing to rats was more than 70% at each designated time and quite closely followed in the in vitro decalcification curve, indicating that the greater part of the calcium ion is released from calcium polycarbophil under normal gastric acidic conditions. The residual radioactivity in rat gastrointestine was nearly equal to that after oral administration of either [45Ca]calcium chloride + polycarbophil. The serum level of radioactivity was nearly equal to that after oral dosing of [45Ca]calcium lactate. These results indicate that the greater part of orally administered calcium polycarbophil released calcium ions to produce polycarbophil in vivo.

  13. Genetic component in rat mammary carcinogenesis

    SciTech Connect

    Vogel, H.J. Jr.; Turner, J.E.

    1982-02-01

    Five genetically defined strains of female rats were exposed to whole-body radiation with a single dose of 50 rad of fission neutrons. After 1 year 56% of the Long-Evans and Sprague-Dawely strains showed at least one mammary tumor; 25-29% of the Buffalo and Fischer-344 strains and only 5% of the Wistar-Lewis strain and palpable mammary tumors. Only one tumor was found among 73 unirradiated controls during the 1-year observation period. Approximately two-thirds of 50 mammary analyzed pathologically were adenofibromas and fibroadenomas; one-third were adenocarcinomas. The Kaplan-Meier method of life table analysis was used to deal with the problem of intercurrent mortality. A genetic factor seems evident in rat mammary tumorigenesis following exposure to fission neutrons.

  14. Cold acclimation in food-restricted rats.

    PubMed

    Puerta, M L; Abelenda, M

    1987-01-01

    Food intake, body weight and brown adipose tissue (BAT) mass and composition of rats exposed at 6 degrees C either with food ad libitum or food-restricted were compared with those of rats in the thermoneutral zone, with food ad libitum. Cold acclimation with food ad libitum increases food intake and prevents body weight gains. IBAT (interscapular BAT) increases its mass and changes its composition after 3 weeks of cold exposure. Cold acclimation with food restriction produces a progressive decrease in body weight. IBAT mass increases after 3 weeks but changes in composition occur sooner. It is concluded that the overfeeding that accompanies cold acclimation is not necessary for non-shivering thermogenesis in BAT.

  15. Testosterone and muscle hypertrophy in female rats

    NASA Technical Reports Server (NTRS)

    Kuhn, F. E.; Max, S. R.

    1985-01-01

    The effects of chronic treatment with testosterone propionate (TP) on compensatory muscle hypertropy in female rats are examined. The 48 female rats were placed in one of four test groups: (1) no overload (synergist removal), no TP, (2) overload, no TP, (3) no overload + TP, and (4) overload + TP. The technique used to administer the TP is described. The preparation of the plantaris muscle, the analysis of pyruvate oxidation and the determination of malate and lactate dehydrogenases and the noncollogen protein are explained. The results which reveal the effect of overload and TP on body weight, noncollogen protein concentration, lactate and malate dehydrogenase activities, and pyruvate oxidation are presented and discussed. It is concluded that in terms of body weight, protein content, pyruvate, glycolysis, and oxidative metabolisms chronic TP treatments do not change compensatory muscle hypertropy.

  16. Aspartame and dental caries in the rat.

    PubMed

    Das, S; Das, A K; Murphy, R A; Worawongvasu, R

    1991-01-01

    Aspartame (NutraSweet--The NutraSweet Co., Deerfield, IL) an artificial intense sweetener, was tested for its cariogenicity alone and in the presence of sucrose. Sprague-Dawley rat pups (Charles River Laboratories, Bloomington, MA) inoculated with Streptococcus mutans were fed basal diet 2000 with one of the following added: 50% sucrose; 30% sucrose; 30% sucrose + 0.15% aspartame; 0.30% aspartame; 0.15% aspartame and no addition. The animals were sacrificed after eight weeks. Caries was evaluated using Keyes' technique. It was found that the addition of 0.15% aspartame to 30% sucrose diet significantly reduced caries in comparison to rats fed only 30% sucrose diet. In animals fed aspartame only, there was no caries. The S. mutans counts were high in the animals receiving sucrose diets with and without aspartame. The animals receiving only aspartame had very low S. mutans counts.

  17. Vapor Inhalation of Alcohol in Rats

    PubMed Central

    Gilpin, Nicholas W.; Richardson, Heather N.; Cole, Maury; Koob, George F.

    2008-01-01

    Alcohol dependence constitutes a neuroadaptive state critical for understanding alcoholism, and various methods have been utilized to induce alcohol dependence in animals, one of which is alcohol vapor exposure. Alcohol vapor inhalation provides certain advantages over other chronic alcohol exposure procedures that share the ultimate goal of producing alcohol dependence in rats. Chronic alcohol vapor inhalation allows the experimenter to control the dose, duration, and pattern of alcohol exposure. Also, this procedure facilitates testing of somatic and motivational aspects of alcohol dependence. Chronic exposure to alcohol vapor produces increases in alcohol-drinking behavior, increases in anxiety-like behavior, and reward deficits in rats. Alcohol vapor inhalation as a laboratory protocol is flexible, and the parameters of this procedure can be adjusted to accommodate the specific aims of different experiments. This unit describes the options available to investigators using this procedure for dependence induction, when different options are more or less appropriate, and the implications of each. PMID:18634001

  18. Biotransformation of norcocaine to norcocaine nitroxide by rat brain microsomes.

    PubMed

    Kloss, M W; Rosen, G M; Rauckman, E J

    1984-01-01

    In the mid 1970's, norcocaine was identified as a metabolite of cocaine in rat brain tissue. We extend these studies by demonstrating that rat brain FAD-containing monooxygenase metabolizes norcocaine to N-hydroxynorcocaine. This hydroxylamine is then further oxidized to the nitroxyl free radical norcocaine nitroxide by rat brain cytochrome P-450. Brain microsomal reduction of norcocaine nitroxide leads to the generation of superoxide. Finally, incubation of rat brain microsomes with either N-hydroxynorcocaine or norcocaine nitroxide leads to significant lipid peroxidation as monitored by spin-trapping techniques.

  19. ENU mutagenesis to generate genetically modified rat models.

    PubMed

    van Boxtel, Ruben; Gould, Michael N; Cuppen, Edwin; Smits, Bart M G

    2010-01-01

    The rat is one of the most preferred model organisms in biomedical research and has been extremely useful for linking physiology and pathology to the genome. However, approaches to genetically modify specific genes in the rat germ line remain relatively scarce. To date, the most efficient approach for generating genetically modified rats has been the target-selected N-ethyl-N-nitrosourea (ENU) mutagenesis-based technology. Here, we describe the detailed protocols for ENU mutagenesis and mutant retrieval in the rat model organism.

  20. Increased Plasma Volume in Hypertensive Rats with Polyarteritis

    PubMed Central

    Gresson, C. R.; Simpson, F. O.

    1974-01-01

    Plasma volume was measured and the severity of gross polyarteritis in the mesenteric vasculature assessed in groups of normotensive and hypertensive rats. Three groups of hypertensive rats were investigated: genetically hypertensive rats of the New Zealand strain, and renal hypertensive rats with one renal artery “clipped” and the opposite kidney either left intact or excised. Polyarteritis of varying severity developed in the mesenteric vasculature in many hypertensive rats, particularly the older ones. No vascular lesions visible to the naked eye were found in the normotensive rats. In rats with moderate to severe polyarteritis plasma volume was increased. Gross dilatation, both generalized and aneurysmal, of the mesenteric arterial tree in affected animals was demonstrated by means of silicone rubber casts. Presumably this and the secondary vascularization of the thickened wall of affected vessels cause an expansion of the intravascular space in rats with polyarteritis and this is a probable factor in the increased plasma volume found in these rats. ImagesFigs. 5-6Figs. 1-4 PMID:4451638

  1. Aging attenuates acquired heat tolerance and hypothalamic neurogenesis in rats.

    PubMed

    Matsuzaki, Kentaro; Katakura, Masanori; Inoue, Takayuki; Hara, Toshiko; Hashimoto, Michio; Shido, Osamu

    2015-06-01

    This study investigated age-dependent changes in heat exposure-induced hypothalamic neurogenesis and acquired heat tolerance in rats. We previously reported that neuronal progenitor cell proliferation and neural differentiation are enhanced in the hypothalamus of long-term heat-acclimated (HA) rats. Male Wistar rats, 5 weeks (Young), 10-11 months (Adult), or 22-25 months (Old) old, were subjected to an ambient temperature of 32°C for 40-50 days (HA rats). Rats underwent a heat tolerance test. In HA rats, increases in abdominal temperature (Tab ) in the the Young, Adult, and Old groups were significantly smaller than those in their respective controls. However, the increase in Tab of HA rats became greater with advancing age. The number of hypothalamic bromodeoxyuridine (BrdU)-immunopositive cells double stained with a mature neuron marker, neuronal nuclei (NeuN), of HA rats was significantly higher in the Young group than that in the control group. In Young HA, BrdU/NeuN-immunopositive cells of the preoptic area/anterior hypothalamus appeared to be the highest among regions examined. Large numbers of newborn neurons were also located in the ventromedial and dorsomedial nuclei, as well as the posterior hypothalamic area, whereas heat exposure did not increase such numbers in the Adult and Old groups. Aging may interfere with heat exposure-induced hypothalamic neurogenesis and acquired heat tolerance in rats.

  2. Creatine kinase reaction rates in rat brain during chronic ischemia.

    PubMed

    Mlynárik, V; Kasparová, S; Liptaj, T; Dobrota, D; Horecký, J; Belan, V

    1998-12-01

    Creatine kinase reaction rates were measured by magnetisation transfer technique in the brain of healthy adult and aged rats and in the rats with mild or severe chronic cerebral ischemia. These measurements indicated that the rate constant of the creatine kinase reaction is significantly reduced in the case of chronic brain ischemia in aged rats. In contrast, occlusion of both carotid arteries in adult rats produced a slight increase in the reaction rate 4 weeks after occlusion. At the same time, corresponding conventional phosphorus magnetic resonance spectra showed negligible changes in signal intensities. PMID:10050942

  3. Adverse effects of sucrose-rich diets on uraemic rats.

    PubMed

    Laouari, D; Kleinknecht, C; Burtin, M; Hinglais, N; Lacour, B; Landais, P; Broyer, M

    1990-01-01

    The nature of carbohydrate may affect the tolerance and progression of uraemia. The effects of three diets differing only in their carbohydrate source: namely corn starch (C), glucose (G) or sucrose (S) were examined. Study 1 examined the effects of the three carbohydrate diets on unilaterally nephrectomised control rats and severely uraemic rats. The three carbohydrates produced similar nutritional effects in uninephrectomised rats, whereas sucrose rapidly induced anorexia, stunting and slightly accelerated renal damage in uraemia. Study 2 examined the long-term effects of the three carbohydrates in moderate uraemia under conditions of high and identical carbohydrate intakes. Hyperphagic Zucker uraemic rats (F rats) received a daily allotment of each diet plus pure carbohydrate. Lean uraemic rats (L rats) received the same dietary allotment without the carbohydrate supplement. The F rats fed sucrose showed greater morbidity and mortality but little renal deterioration. Their plasma triglycerides increased dramatically. The L rats fed sucrose had the greatest urinary protein, the least creatinine clearance and the most severe renal damage. Thus, sucrose-rich but not glucose-rich diets have two adverse effects in uraemia: a deterioration in nutritional status, perhaps related to abnormal fructose utilisation, and a long-term effect on the kidney, resulting in accelerated renal deterioration.

  4. Estradiol increases salt intake in female normotensive and hypertensive rats.

    PubMed

    Kensicki, Eric; Dunphy, Gail; Ely, Daniel

    2002-08-01

    The objective of this study was to examine whether or not estradiol (E2) alters sodium intake in hypertensive and normotensive female rats. It was hypothesized that higher doses of E2 would increase sodium consumption and that this response would be greater in spontaneously hypertensive rats (SHR) compared with Wistar Kyoto (WKY) rats. The study involved female SHR and WKY (n = 12/group). All animals were ovariectomized. Six of twelve rats from each strain received three progressively larger doses of beta-estradiol propionate (each dose lasting 2 wk), whereas the other six rats from each strain received sham implants. Blood E2 levels were measured by radioimmunoassay after each 2-wk period, allowing a 10-day washout period before the next E2 dose. Rats had access to 0.0, 0.5, 1.0, and 1.5% NaCl solutions to drink throughout the experiment. There was a significant positive correlation between sodium intake and plasma E2 (r = 0.8, P < 0.001). Both strains avoided the 1.5% NaCl, and the increased sodium intake was achieved by an increase in consumption of the 0.5% NaCl. SHR females consumed more sodium than WKY females, which is similar to what has been observed in males of these strains. In conclusion, E2 was positively correlated with sodium intake in both strains of rat, with the hypertensive rats consuming more sodium than the normotensive rats.

  5. Formation of retinoic acid from retinol in the rat

    PubMed Central

    Emerick, R. J.; Zile, Maija; DeLuca, H. F.

    1967-01-01

    1. The formation in vivo of retinoic acid from microgram quantities of intrajugularly administered [15-14C]retinol was demonstrated in the rat. 2. Endogenously formed retinoic acid (about 0·1μg./rat) was found in liver, and to a much smaller extent in intestine, 12hr. after retinol administration. 3. Excretion of some of the endogenously formed retinoic acid occurred in the bile of bile-duct-cannulated rats. 4. Excretion of unaltered retinoic acid in the urine of intact rats did not occur even after the intrajugular administration of preformed retinoic acid. PMID:6029617

  6. MODELING VOLATILE ORGANIC COMPOUND PHARMACOKINETICS IN RAT PUPS

    EPA Science Inventory

    PBPK model predictions of internal dosimetry in young rats were compared to adult animals for benzene, chloroform (CHL), methylene chloride, methyl ethly ketone (MEK), perchloroethylene, and trichloroethylene.

  7. Lead induced testicular changes in protein malnourished rats.

    PubMed

    Saxena, D K; Murthy, R C; Lal, B; Chandra, S V

    1989-01-01

    The effect of concurrent low protein (8% casein) diet and lead (Pb) exposure (1 mg/ml lead acetate in drinking water) on testes of weaned rats up to 90 days of age was investigated Histopathological examination of testes of lead treated rats maintained on low protein diet revealed marked pathological changes associated with greatly reduced succinic dehydrogenase, glucose-6-phosphate dehydrogenase and adenosine triphosphatase activity as revealed histochemically compared to lead treated rats fed normal protein diet. It was concluded that higher accumulation of lead may be responsible for altering the enzyme levels and inducing the testicular degeneration to a greater extent in low protein fed rats compared to their counterpart controls.

  8. Strain differences in toxic effects of long-lasting isoflurane anaesthesia between Wistar rats and Sprague Dawley rats.

    PubMed

    Siller-Matula, J M; Jilma, B

    2008-11-01

    We investigated if long-lasting (5 h) anaesthesia with isoflurane has different pharmacological effects in two different rat strains: Wistar and Sprague Dawley. The mean blood pressure was 34% higher in Sprague Dawley rats as compared to the Wistar rats (p = 0.04). In Wistar rats, the pH value decreased to 7.1, lactate increased by 53%, creatinine increased 2.7-fold, alanine amino transferase and aspartate amino transferase increased more than 4-fold and lactate dehydrogenase increased 9-fold (p < 0.05). There were no changes in laboratory parameters in Sprague Dawley rats. This indicates that the Wistar rats were more sensitive to a 5 h anaesthesia with isoflurane after a premedication with ketamin/xylazine in the described study design.

  9. Chronic Paraspinal Muscle Injury Model in Rat

    PubMed Central

    Cho, Tack Geun; Kim, Young Baeg

    2016-01-01

    Objective The objective of this study is to establish an animal model of chronic paraspinal muscle injury in rat. Methods Fifty four Sprague-Dawley male rats were divided into experimental group (n=30), sham (n=15), and normal group (n=9). Incision was done from T7 to L2 and paraspinal muscles were detached from spine and tied at each level. The paraspinal muscles were exposed and untied at 2 weeks after surgery. Sham operation was done by paraspinal muscles dissection at the same levels and wound closure was done without tying. Kyphotic index and thoracolumbar Cobb's angle were measured at preoperative, 2, 4, 8, and 12 weeks after the first surgery for all groups. The rats were sacrificed at 4, 8, and 12 weeks after the first surgery, and performed histological examinations. Results At 4 weeks after surgery, the kyphotic index decreased, but, Cobb's angle increased significantly in the experimental group (p<0.05), and then that were maintained until the end of the experiment. However, there were no significant differences of the kyphotic index and Cobb's angle between sham and normal groups. In histological examinations, necrosis and fibrosis were observed definitely and persisted until 12 weeks after surgery. There were also presences of regenerated muscle cells which nucleus is at the center of cytoplasm, centronucleated myofibers. Conclusion Our chronic injury model of paraspinal muscles in rats shows necrosis and fibrosis in the muscles for 12 weeks after surgery, which might be useful to study the pathophysiology of the degenerative thoracolumbar kyphosis or degeneration of paraspinal muscles.

  10. The fate of propoxur in rat.

    PubMed

    Foss, W; Krechniak, J

    1980-01-01

    The dynamics of absorption, distribution, biotransformation, and excretion of propoxur in rat was studied. The animals were given single doses of propoxur: a) 5 mg/kg intravenously (i.v.), b) 5 mg/kg 14-C labelled compound (1.5 muCi) intravenously, c) 50 mg/kg orally. The concentrations of propoxur and its metabolite 2-isopropoxyphenol were determined in blood, liver, kidneys, brain and urine. Pharmacokinetic data concerning absorption, distribution and excretion were calculated.

  11. Pharmacokinetic Profile of Spectinomycin in Rats

    PubMed Central

    Madhura, Dora Babu; Lee, Richard; Meibohm, Bernd

    2014-01-01

    Short Summary Following intravenous (IV) administration, the pharmacokinetics of spectinomycin in rats was found to be on par with its profile in other mammalian species including humans with respect to its overall excretion and half-life at effective concentrations. This study, however, indicates that a small fraction of the spectinomycin dose is retained in peripheral tissues for a prolonged period of time at low concentrations. PMID:24020122

  12. D-RATS 2011: RAFT Protocol Overview

    NASA Technical Reports Server (NTRS)

    Utz, Hans

    2011-01-01

    A brief overview presentation on the protocol used during the D-RATS2011 field test for file transfer from the field-test robots at Black Point Lava Flow AZ to Johnson Space Center, Houston TX over a simulated time-delay. The file transfer actually uses a commercial implementation of an open communications standard. The focus of the work lies on how to make the state of the distributed system observable.

  13. Autoradiographic studies of the rat renotropic system.

    PubMed

    Castillo, O; Robertson, D; Goldin, H; Preuss, H G

    1980-01-01

    Rat sera, 10-30 h after unilateral nephrectomy (UNI), enhance 3H-thymidine ("3H-Tdr) incorporation into DNA of incubating renal tissue from control rats. Stimulation is even greater when extracts from remaining growing kidneys 20 h after UNI are combined with sera from rats after UNI. UNI extracts, i.e., extracts from the kidney remaining after uninephrectomy, are nonstimulatory alone. UNI sera and UNI sera plus UNI extracts could theoretically augment 3H-Tdr incorporation into renal DNA via dilutional means rather than enhanced DNA synthesis. To determine if our results were secondary to enhanced DNA synthesis, we performed our in vitro assay using the labelling of nuclei via autoradiography as another index. The addition of UNI sera compared to sera from sham-operated rats (SHAM) in seven paired experiments enhanced incorporation of 3H-Tdr into DNA by 30% (p less than 0.02) and the addition of both UNI sera and UNI extracts compared to SHAM sera and SHAM extracts enhanced incorporation by 48% (p less than 0.001). Unlike a dilutional effect, nuclear labelling also increased in these same seven experiments: UNI sera versus SHAM sera increased 25% (p less than 0.05) and UNI sera + UNI extracts versus SHAM sera + SHAM extracts increased 37% (p less than 0.01). We conclude that UNI sera and UNI sera + UNI extracts enhance 3H-Tdr incorporation into DNA by augmenting DNA synthesis, driving cells into the "S" phase. The use of 3H-Tdr incorporation into DNA in our assay does estimate DNA synthesis.

  14. Favism: divicine hemotoxicity in the rat.

    PubMed

    McMillan, D C; Jollow, D J

    1999-10-01

    Favism is an acute hemolytic anemia known to occur in susceptible individuals who ingest fava beans. Susceptibility to favism is conferred by a genetic deficiency in erythrocytic glucose-6-phosphate dehydrogenase (G6PD) activity. Although the fava bean pyrimidine aglycones, divicine and isouramil, have been implicated in the onset of favism in humans, the lack of a well-defined experimental animal model for favism has hampered progress in elucidating the mechanism underlying hemotoxicity. We have examined whether a favic-like response could be provoked in G6PD-normal rats treated with synthetic divicine. Intraperitoneal administration of divicine to rats preloaded with 51Cr-tagged erythrocytes resulted in a severe, dose-dependent decrease in blood radioactivity (TD50 approximately 0.5 mmol/kg) within 24 h. The increased rate of removal of blood radioactivity was accompanied by a rapid decline in reduced glutathione levels in the blood, decreased hematocrits, marked hemoglobinuria, splenic enlargement, and reticulocytosis. In vitro exposure of 51Cr-tagged red cells to divicine before their re-administration to isologous rats also resulted in a sharp, concentration-dependent decrease in erythrocyte survival in vivo (TC50 approximately 1.5 mM), and these divicine-damaged red cells were removed from the circulation by the spleen. These data demonstrate that a favic response can be induced in G6PD-normal rats treated with divicine, and that hemolytic activity can be reproduced in isolated red cells under conditions that will allow a direct examination of the mechanism underlying this hemotoxicity. PMID:10543033

  15. Toxicity evaluation of crankcase oil in rats

    PubMed Central

    Arise, R.O.; Tella, A.C.; Akintola, A.A.; Akiode, S.O.; Malomo, S.O.

    2012-01-01

    The aim of this study was to investigate the effect of crankcase oil on the cellular and functional integrity of rat skin. Thirty (30) rats were randomly grouped into six viz groups A-F. Group A (base-line control) received 2 ml of distilled water. 2.5 %, 5.0 %, 7.5 %, and 10.0 % v/v of the crankcase oil were prepared using unused oil as solvent and 2 ml of the concentrations were topically administered to groups C-F respectively for seven consecutive days. Group B served as positive control and received 2 ml of the unused oil. The rats were sacrificed 24 hours after the last administration, and blood and part of the skin were collected. Alkaline phosphatase (ALP), acid phosphatase (ACP), superoxide dismutase (SOD) and malondialdehyde level in the blood and skin samples collected were evaluated. Elemental analysis of the crankcase oil was also carried out. The result revealed high lead, iron and chromium levels. Blood lead concentration of rats was significantly (P<0.05) high after seven days of administration. ALP level in skin and serum increased significantly (P<0.05) with the concentration of crankcase oil. There was a significant decrease (P<0.05) in skin ACP activity while it increased significantly (P<0.05) in the serum. Similar results were observed in the SOD levels of the serum and the skin. The level increased significantly (P<0.05) in groups D-F when compared with controls. The MDA concentration of both serum and skin were significantly (P<0.05) elevated. This suggests toxic potential of used lubricating oil and its potential predisposition to cancer. PMID:27366138

  16. Chemical Renal Denervation in the Rat

    SciTech Connect

    Consigny, Paul M. Davalian, Dariush; Donn, Rosy Hu, Jie; Rieser, Matthew Stolarik, DeAnne

    2013-12-03

    Introduction: The recent success of renal denervation in lowering blood pressure in drug-resistant hypertensive patients has stimulated interest in developing novel approaches to renal denervation including local drug/chemical delivery. The purpose of this study was to develop a rat model in which depletion of renal norepinephrine (NE) could be used to determine the efficacy of renal denervation after the delivery of a chemical to the periadventitial space of the renal artery. Methods: Renal denervation was performed on a single renal artery of 90 rats (n = 6 rats/group). The first study determined the time course of renal denervation after surgical stripping of a renal artery plus the topical application of phenol in alcohol. The second study determined the efficacy of periadventitial delivery of hypertonic saline, guanethidine, and salicylic acid. The final study determined the dose–response relationship for paclitaxel. In all studies, renal NE content was determined by liquid chromatography–mass spectrometry. Results: Renal NE was depleted 3 and 7 days after surgical denervation. Renal NE was also depleted by periadventitial delivery of all agents tested (hypertonic saline, salicylic acid, guanethidine, and paclitaxel). A dose response was observed after the application of 150 μL of 10{sup −5} M through 10{sup −2} M paclitaxel. Conclusion: We developed a rat model in which depletion of renal NE was used to determine the efficacy of renal denervation after perivascular renal artery drug/chemical delivery. We validated this model by demonstrating the efficacy of the neurotoxic agents hypertonic saline, salicylic acid, and guanethidine and increasing doses of paclitaxel.

  17. Proteomic profiling of the rat hypothalamus

    PubMed Central

    2012-01-01

    Background The hypothalamus plays a pivotal role in numerous mechanisms highly relevant to the maintenance of body homeostasis, such as the control of food intake and energy expenditure. Impairment of these mechanisms has been associated with the metabolic disturbances involved in the pathogenesis of obesity. Since rodent species constitute important models for metabolism studies and the rat hypothalamus is poorly characterized by proteomic strategies, we performed experiments aimed at constructing a two-dimensional gel electrophoresis (2-DE) profile of rat hypothalamus proteins. Results As a first step, we established the best conditions for tissue collection and protein extraction, quantification and separation. The extraction buffer composition selected for proteome characterization of rat hypothalamus was urea 7 M, thiourea 2 M, CHAPS 4%, Triton X-100 0.5%, followed by a precipitation step with chloroform/methanol. Two-dimensional (2-D) gels of hypothalamic extracts from four-month-old rats were analyzed; the protein spots were digested and identified by using tandem mass spectrometry and database query using the protein search engine MASCOT. Eighty-six hypothalamic proteins were identified, the majority of which were classified as participating in metabolic processes, consistent with the finding of a large number of proteins with catalytic activity. Genes encoding proteins identified in this study have been related to obesity development. Conclusion The present results indicate that the 2-DE technique will be useful for nutritional studies focusing on hypothalamic proteins. The data presented herein will serve as a reference database for studies testing the effects of dietary manipulations on hypothalamic proteome. We trust that these experiments will lead to important knowledge on protein targets of nutritional variables potentially able to affect the complex central nervous system control of energy homeostasis. PMID:22519962

  18. Cocaine and "pharmacological kindling" in the rat.

    PubMed

    Stripling, J S

    1983-11-01

    The concept of "pharmacological kindling" has been used to explain the behavioral sensitization to cocaine produced by repeated administration of subconvulsive doses. This idea was tested by the repeated administration of cocaine to rats followed by electrical kindling of the olfactory bulb (a site at which cocaine has prominent electrophysiologic effects). No significant effect of cocaine on kindling was found. The relationship of this finding to studies using other drugs is discussed.

  19. The effects of alcohol on rat placenta.

    PubMed

    Turan Akay, Mehmet; Arzu Koçkaya, Evrim

    2005-01-01

    In this study, daily food and water consumption and body weights, histopathology of placenta, tenascin (TN), type IV collagen and EGF and its receptor immunolocalization in the placenta of albino rats treated with two doses of alcohol (1 and 5 g kg(-1) day(-1)) were determined. Alcohol was administered in three different periods i.e. the whole 4 weeks before the pregnancy, during the pregnancy, and during the 4 weeks before the pregnancy plus pregnancy itself. The samples of placenta obtained from control and treated rats on days 10, 12, 14, 16, 18, 20 and 21 of gestation were evaluated morphologically and fixed for histology and immunohistochemistry. Some differences in food and water consumption between the groups were determined. The placental weight, especially in the groups receiving 1 and 5 g kg(-1) day(-1) alcohol during the pregnancy, showed increases. The changes in placental histology such as increases in the number and the size of trophoblastic giant cells, cytoplasmic dissolution and nuclear polymorphism, degenerations in spongiotrophoblasts, hyperemia at the basal zone and labyrinth, hyperplasia at the labyrinth and irregular vascularization were seen particularly in the groups receiving alcohol during the pregnancy, and during the 4 weeks before the pregnancy plus pregnancy itself. Increases in the immunolocalization of TN and type IV collagen and decreases in the immunolocalization of EGF and EGFR in the placentas of alcohol-receiving rats were found. In conclusion, ethanol treatment during pregnancy in rats affected placentation and the immunolocalization of TN, type IV collagen, EGF and EGFR in the placentas.

  20. The CCD cameras of RATS project.

    NASA Astrophysics Data System (ADS)

    Scuderi, S.; Claudi, R. U.; Favata, F.; Bonanno, G.; Bruno, P.; Cosentino, R.; Belluso, M.; Calí, A.; Timpanaro, M. C.; Chiomento, V.; Farisato, G.; Frigo, A.; Gianesini, G.; Traverso, L.; Rebeschini, M.; Strazzabosco, D.

    We report on the characteristics and the performances of the CCD cameras that will be used by the project RATS (RAdial velocity and Transit Search) that is an italian-ESA collaboration whose main goal is the search of extrasolar planet using the transit method. We describe the characteristics of the variuos cameras and the first tests at the Asiago Schmidt telescope at Cima Ekar.

  1. Oxalic acid decreases calcium absorption in rats

    SciTech Connect

    Weaver, C.M.; Martin, B.R.; Ebner, J.S.; Krueger, C.A.

    1987-11-01

    Calcium absorption from salts and foods intrinsically labeled with /sup 45/Ca was determined in the rat model. Calcium bioavailability was nearly 10 times greater for low oxalate kale, CaCO/sub 3/ and CaCl/sub 2/ than from CaC/sub 2/O/sub 4/ (calcium oxalate) and spinach (high in oxalates). Extrinsic and intrinsic labeling techniques gave a similar assessment of calcium bioavailability from kale but not from spinach.

  2. Chronic Paraspinal Muscle Injury Model in Rat

    PubMed Central

    Cho, Tack Geun; Kim, Young Baeg

    2016-01-01

    Objective The objective of this study is to establish an animal model of chronic paraspinal muscle injury in rat. Methods Fifty four Sprague-Dawley male rats were divided into experimental group (n=30), sham (n=15), and normal group (n=9). Incision was done from T7 to L2 and paraspinal muscles were detached from spine and tied at each level. The paraspinal muscles were exposed and untied at 2 weeks after surgery. Sham operation was done by paraspinal muscles dissection at the same levels and wound closure was done without tying. Kyphotic index and thoracolumbar Cobb's angle were measured at preoperative, 2, 4, 8, and 12 weeks after the first surgery for all groups. The rats were sacrificed at 4, 8, and 12 weeks after the first surgery, and performed histological examinations. Results At 4 weeks after surgery, the kyphotic index decreased, but, Cobb's angle increased significantly in the experimental group (p<0.05), and then that were maintained until the end of the experiment. However, there were no significant differences of the kyphotic index and Cobb's angle between sham and normal groups. In histological examinations, necrosis and fibrosis were observed definitely and persisted until 12 weeks after surgery. There were also presences of regenerated muscle cells which nucleus is at the center of cytoplasm, centronucleated myofibers. Conclusion Our chronic injury model of paraspinal muscles in rats shows necrosis and fibrosis in the muscles for 12 weeks after surgery, which might be useful to study the pathophysiology of the degenerative thoracolumbar kyphosis or degeneration of paraspinal muscles. PMID:27651859

  3. Characterization of prostanoid receptors on rat neutrophils.

    PubMed Central

    Wise, H; Jones, R L

    1994-01-01

    1. The effects of various prostanoid agonists have been compared on the increase in intracellular free calcium ([Ca2+]i) and the aggregation reaction of rat peritoneal neutrophils induced by N-formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP). 2. Prostaglandin E2 (PGE2) and the specific IP-receptor agonist, cicaprost, both inhibited the FMLP-induced increase in [Ca2+]i (IC50 33 nM and 18 nM respectively) and the FMLP-induced aggregation reaction (IC50 5.6 nM and 7.9 nM respectively). PGD2, PGF2 alpha, and the TP-receptor agonist, U 46619, were inactive at the highest concentration tested (1 microM). 3. The EP1-receptor agonist, 17-phenyl-omega-trinor PGE2, and the EP3-receptor agonists, GR 63799X and sulprostone, had no inhibitory effect on FMLP-stimulated rat neutrophils. 4. PGE1 (EP/IP-receptor agonist) and iloprost (IP-receptor agonist) inhibited the FMLP-induced increase in [Ca2+]i with IC50 values of 34 nM and 38 nM respectively. The EP2-receptor agonists, butaprost and misoprostol (1 microM), inhibited both FMLP-stimulated [Ca2+]i and aggregation. However another EP2-receptor agonist, AH 13205, was inactive in both assays. 5. Prostanoid receptors present on rat neutrophils were further characterized by measuring [3H]-adenosine 3':5'-cyclic monophosphate ([3H]-cyclic AMP) accumulation. Only those agonists capable of stimulating [3H]-cyclic AMP accumulation were able to inhibit both FMLP-stimulated [Ca2+]i and aggregation. 6. These results indicate that rat neutrophils possess inhibitory IP and EP-receptors; the relative potencies of PGE2, misoprostol and butaprost are those expected for the EP2-receptor subtype. No evidence for DP, FP, TP or EP1 and EP3-receptors was obtained. PMID:7834211

  4. Methionine, pyridoxine and endothelial lesion in rats.

    PubMed

    Hladovec, J

    1980-01-01

    Methionine administered orally to rats produced a prolonged dose-dependent increase in endothelemia. The increase was observed after doses exceeding 100 mg/kg and was inhibited by a simultaneous administration of pyridoxine. The effect of methionine was also inhibited by trihydroxyethylrutoside and acetylsalicyclic acid. Endothelemia was increased furthermore by oral administration of cysteine and cystine and this increase was again inhibited by pyridoxine.

  5. Enzyme studies in the articular cartilage of diabetic rats and of rats bearing transplanted pancreatic islets.

    PubMed

    Silberberg, R; Hirshberg, G E; Lesker, P

    1977-08-01

    The articular cartilage of normal rats, of rats made diabetic with streptozotocin, and of rats made diabetic with streptozotocin and subsequently transplanted with isologous pancreatic islets was examined for the activities of enzymes engaged in the synthesis and degradation of glycosaminoglycans (mucopolysaccharides). The activities assayed were those of the degrading enzymes B-glucuronidase, B-acetyglucosaminidase, B-acetylgalactosaminidase, B-galactosidase, and those active in synthesis: uridine diphosphate dehydrogenase, glucose-6-phosphate dehyrogenase, and phosphofructokinase. In the diabetic animals all enzyme activities were increased, thos of the degrading enzymes more than those of the others. Implantation of pancreatic islets reversed the changes produced by diabetes, enzyme activities returning to near-normal levels. PMID:142034

  6. Obesity-resistant S5B rats showed great cocaine conditioned place preference than the obesity-prone OM rats

    SciTech Connect

    Thanos, P.K.; Wang, G.; Thanos, P.K..; Kim, R.; Cho, J.; Michaelides, M.; Anderson, B.J.; Primeaux, S.D.; Bray, G.A.; Wang, G.-J.; Robinson, J.K.; Volkow, N.D.

    2010-12-01

    Dopamine (DA) and the DA D2 receptor (D2R) are involved in the rewarding and conditioned responses to food and drug rewards. Osborne-Mendel (OM) rats are genetically prone and S5B/P rats are genetically resistant to obesity when fed a high-fat diet. We hypothesized that the differential sensitivity of these two rat strains to natural rewards may also be reflected in sensitivity to drugs of abuse. Therefore, we tested whether OM and S5B/P rats showed a differential preference to cocaine using conditioned place preference (CPP). To also evaluate whether there is specific involvement of the D2R in this differential conditioning sensitivity, we then tested whether the D2R agonist bromocriptine (BC) would differentially affect the effects of cocaine in the two strains. OM and S5B/P rats were conditioned with cocaine (5 or 10 mg/kg) in one chamber and saline in another for 8 days. Rats were then tested for cocaine preference. The effects of BC (0.5, 1, 5, 10, 20 mg/kg) on cocaine preference were then assessed in subsequent test sessions. OM rats did not show a significant preference for the cocaine-paired chamber on test day. Only the S5B/P rats showed cocaine CPP. Later treatment with only the highest dose of BC resulted in reduced cocaine CPP in S5B/P rats when treated with 5 mg/kg cocaine and in OM rats treated with 10 mg/kg cocaine. Our results indicated that obesity-resistant S5B rats showed greater cocaine CPP than the obesity-prone OM rats. These findings do not support a theory of common vulnerability for reinforcer preferences (food and cocaine). However, they show that BC reduced cocaine conditioning effects supporting at least a partial regulatory role of D2R in conditioned responses to drugs.

  7. Postprandial hemodynamics in the conscious rat

    SciTech Connect

    Anzueto Hernandez, L.; Kvietys, P.R.; Granger, D.N.

    1986-07-01

    The postprandial intestinal hyperemia was studied in conscious and anesthetized rats using the radioactive microsphere technique. Carbohydrate, protein, lipid, and mixed meals, and the vehicle (Tyrode's solution), were placed in the stomach via a gastrostomy tube. In conscious rats, blood flow increased by 40-80% in the duodenum and jejunum 1 h after either a carbohydrate, lipid, protein, or mixed meal. Tyrode's solution produced a comparable hyperemia. Blood flow in the distal bowel segments (ileum, cecum, and colon) was significantly increased only by Tyrode's solution and the carbohydrate meal. The proximal intestinal hyperemia produced by the mixed meal in conscious animals was significantly attenuated by vagotomy yet unaltered by atropine pretreatment. In contrast to the results obtained from conscious rats, the mixed meal did not significantly alter intestinal blood flow in anesthetized animals. The results of this study indicate that the postprandial intestinal hyperemia is much greater in conscious than anesthetized animals. This difference may result from the higher resting blood flows in the latter group. The hyperemic response in conscious animals may be mediated by the vagus nerve.

  8. Daily body energy balance in rats.

    PubMed

    Le Magnen, J; Devos, M

    1982-11-01

    The aim of the present study was to examine the balance between caloric intake and expenditures in successive 12 and 24 hour periods, for several consecutive days in rats. The simultaneous and continuous measurements of respiratory exchanges and of the spontaneous feeding pattern were performed in 6 rats during 38 days, in periods of 2 to 4 successive days. At night, caloric intake exceeded caloric expenditures by 32% on the average. In individual rats, the excess was positively correlated to meal size but not to meal number. During the daytime, caloric intake was 24% lower on the average than the concomitant energy expenditures. In individual subjects, these deficits were correlated to meal number but not to meal size. A nocturnal excess and the subsequent daytime deficit, and the diurnal deficit and the excess during the subsequent night were highly positively correlated. In fact, the 24 hour energy balance was either slightly positive (12% excess) or negative (4% deficit). The daily weight gain or loss was highly correlated to the residual excess and/or deficit with a mean caloric cost of 4.8 kcal per g of body weight. The absence of correlation between balances on successive days indicates that the body energy balance is regulated within 24 hr through 12/12 hr compensations and that no compensatory mechanisms are involved beyond 24 hr.

  9. Intravenous angiotensin and salt appetite in rats.

    PubMed

    Fitts, Douglas A; Zierath, Dannielle K; Savos, Anna V; Ho, Jacqueline M; Bassett, John E

    2007-01-01

    Circulating angiotensin II is crucial for the activation of salt appetite after sodium depletion. We tested if angiotensin (ANG) II infused intravenously at 50 ng/kg/min overnight (chronic) can mimic the rapid salt appetite similar to furosemide and overnight sodium depletion. In experiment 1, rats received chronic ANG II or vehicle infusions all night with access to water and chow but no saline solution. In the morning, the infusions continued, but half of the vehicle-infused group was switched to ANG II (acute). Thirty minutes after the switch, all rats received 10 mg/kg furosemide SC. One hour later they were provided water and 0.3 M NaCl to drink. Rats infused with vehicle or acute ANG drank little, but the chronic ANG group drank 11+/-1 ml of saline in 90 min. In experiment 2, the furosemide was omitted, and a group receiving a chronic infusion of phenylephrine at 6.25 microg/kg/min was included. The chronic ANG group drank 10+/-1 ml saline in 90 min, but the phenylephrine group, which also incurred a significant negative sodium balance overnight, drank little. Thus, an overnight infusion of ANG II is sufficient to mimic the robust expression of salt appetite as observed after furosemide and overnight sodium depletion.

  10. Arsenic-cadmium interaction in rats.

    PubMed

    Díaz-Barriga, F; Llamas, E; Mejía, J J; Carrizales, L; Santoyo, M E; Vega-Vega, L; Yáñez, L

    1990-11-01

    Simultaneous exposure to cadmium and arsenic is highly probable in the urban area of San Luis Potosi, Mexico due to common localization of copper and zinc smelters. Therefore, in this work, rats were intraperitoneally exposed either to cadmium or arsenic alone, or simultaneously to both metals. The effects of these treatments on three different toxicological parameters were studied. Cadmium modified the LD50 of arsenic and conversely arsenic modified the LD50 for cadmium. At the histopathological level, arsenic appeared to protect against the cadmium effects, especially on testes. This protective effect seemed to be related to the glutathione levels found in this tissue: rats exposed to both arsenic and cadmium, presented glutathione values intermediate to those observed after exposure to either metal alone; arsenic had the highest value and cadmium the lowest. In liver, rats exposed to arsenic, cadmium or arsenic and cadmium, presented glutathione values below those in the saline group, with the lowest value corresponding to the arsenic and cadmium treatment. The results appear to support the proposed interaction between arsenic and cadmium and coexposure to both metals seems to alter certain effects produced by either metal alone. PMID:2219140

  11. Quantification of gait in dystonic Gunn rats.

    PubMed

    Chaniary, Kunal D; Baron, Mark S; Rice, Ann C; Wetzel, Paul A; Ramakrishnan, Viswanathan; Shapiro, Steven M

    2009-06-15

    Spontaneously jaundiced Gunn rats exposed to sulfadimethoxine develop bilirubin encephalopathy (kernicterus) with hearing loss and dystonia, closely resembling the human syndrome. We recently characterized the electromyographic activity in this animal model supporting our clinical impression of dystonia. The objective of this study was to develop a simple, non-invasive method to quantify the motor deficits in dystonic rodents. On postnatal day 16, Gunn rats were treated with 100mg/kg of sulfadimethoxine or saline. On postnatal day 31, the ventral view of the animals was videotaped while the animals walked inside a Plexiglas chamber. Individual video frames were reviewed and specific gait parameters including hindlimb spread, step length ratio variability, stance/swing ratio and walking speed were compared between dystonic and non-dystonic jaundiced and non-jaundiced littermates. Data analysis demonstrated statistically significant increases in hindlimb spread and step length ratio variability and decreases in walking speed in dystonic animals as compared to controls. This study demonstrates a valuable technique to objectively characterize dystonia in Gunn rats, which could have wide use for other experimental movement disorders as well. PMID:19464517

  12. Effects of optimism on motivation in rats.

    PubMed

    Rygula, Rafal; Golebiowska, Joanna; Kregiel, Jakub; Kubik, Jakub; Popik, Piotr

    2015-01-01

    In humans, optimism is a cognitive construct related to motivation; optimists exert effort, whereas pessimists disengage from effort. In this study, using a recently developed ambiguous-cue interpretation (ACI) paradigm we took the unique opportunity to investigate whether "optimism" as a trait is correlated with motivation in rodents. In a series of ACI tests (cognitive bias screening, CBS), we identified rats displaying "pessimistic" and "optimistic" traits. Subsequently, we investigated the trait differences in the motivation of these rats to gain reward and to avoid punishment using a progressive ratio (PR) schedule of reinforcement paradigm. Although "optimistic" and "pessimistic" animals did not differ in their motivation to avoid punishment, the "optimistic" rats were significantly more motivated to gain reward than their "pessimistic" conspecifics. For the first time, we showed an association between cognitive judgment bias and motivation in an animal model. Because both investigated processes are closely related to mental health and wellbeing, our results may be valuable for preclinical modeling of many psychiatric disorders.

  13. Rat Model of Parkes Weber Syndrome

    PubMed Central

    Bojakowski, Krzysztof; Janusz, Gabriela; Grabowska, Iwona; Zegrocka-Stendel, Oliwia; Surowiecka-Pastewka, Agnieszka; Kowalewska, Magdalena; Maciejko, Dorota; Koziak, Katarzyna

    2015-01-01

    The Parkes Weber syndrome is a congenital vascular malformation, characterized by varicose veins, arterio-venous fistulas and overgrown limbs. No broadly accepted animal model of Parkes Weber syndrome has been described. We created side-to-side arterio-venous fistula between common femoral vessels with proximal non-absorbable ligature on common femoral vein limiting the enlargement of the vein diameter in Wistar rats. Contralateral limb was sham operated. Invasive blood pressure measurements in both iliac and inferior cava veins were performed in rats 30 days after fistula creation. Tight circumference and femoral bone length were measured. Histopathology and morphology of soleus muscle, extensor digitorum longus muscle, and the common femoral vessel were analyzed. 30 days following arterio-venous fistula creation, a statistically significant elevation of blood pressure in common iliac vein and limb overgrowth was observed. Limb enlargement was caused by muscle overgrowth, varicose veins formation and bone elongation. Arterio-venous fistula with proximal outflow limitation led to significant increase of femoral vein circumference and venous wall thickness. Our study indicates that the described rat model mimics major clinical features characteristic for the human Parkes Weber syndrome: presence of arterio-venous fistula, venous hypertension and dilatation, varicose veins formation, and the limb hypertrophy. We reveal that limb overgrowth is caused by bone elongation, muscle hypertrophy, and venous dilatation. The newly established model will permit detailed studies on the mechanisms underlying the disease and on the efficacy of novel therapeutic strategies for the Parkes Weber syndrome treatment. PMID:26217941

  14. Rat Model of Parkes Weber Syndrome.

    PubMed

    Bojakowski, Krzysztof; Janusz, Gabriela; Grabowska, Iwona; Zegrocka-Stendel, Oliwia; Surowiecka-Pastewka, Agnieszka; Kowalewska, Magdalena; Maciejko, Dorota; Koziak, Katarzyna

    2015-01-01

    The Parkes Weber syndrome is a congenital vascular malformation, characterized by varicose veins, arterio-venous fistulas and overgrown limbs. No broadly accepted animal model of Parkes Weber syndrome has been described. We created side-to-side arterio-venous fistula between common femoral vessels with proximal non-absorbable ligature on common femoral vein limiting the enlargement of the vein diameter in Wistar rats. Contralateral limb was sham operated. Invasive blood pressure measurements in both iliac and inferior cava veins were performed in rats 30 days after fistula creation. Tight circumference and femoral bone length were measured. Histopathology and morphology of soleus muscle, extensor digitorum longus muscle, and the common femoral vessel were analyzed. 30 days following arterio-venous fistula creation, a statistically significant elevation of blood pressure in common iliac vein and limb overgrowth was observed. Limb enlargement was caused by muscle overgrowth, varicose veins formation and bone elongation. Arterio-venous fistula with proximal outflow limitation led to significant increase of femoral vein circumference and venous wall thickness. Our study indicates that the described rat model mimics major clinical features characteristic for the human Parkes Weber syndrome: presence of arterio-venous fistula, venous hypertension and dilatation, varicose veins formation, and the limb hypertrophy. We reveal that limb overgrowth is caused by bone elongation, muscle hypertrophy, and venous dilatation. The newly established model will permit detailed studies on the mechanisms underlying the disease and on the efficacy of novel therapeutic strategies for the Parkes Weber syndrome treatment. PMID:26217941

  15. Innervation of the rat thymus gland.

    PubMed

    Kendall, M D; al-Shawaf, A A

    1991-03-01

    Current views from different laboratories on the innervation of the thymus gland are reviewed with particular reference to the rat. Noradrenergic nerve profiles of the sympathetic nervous system have been demonstrated in the subcapsular cortex, at the corticomedullary junction and in the cortex itself, and extremely sparsely in the medulla. By following beta-adrenergic receptor development in postnatal rats, it has been shown that there is a marked increase in density and morphological organization of the receptor in the medulla with the maturation of thymocyte function (monitored by measuring the proliferation response to concanavalin A) and a sexual dimorphism during the ontogeny of the receptor. Chemical sympathectomy of adult rats with 6-hydroxydopamine (6-OHDA) or guanethidine resulted in a loss of thymus weight, decreased cellularity, and increased apoptosis but a rise in the numbers of proliferating cells in the cortex. By contrast, proliferation of peripheral T cells was reduced after the use of 6-OHDA. Chemical sympathectomy also demonstrated that there were at least three nerve nets in the gland: noradrenergic neural profiles that were destroyed with both 6-OHDA and guanethidine, vasoactive intestinal polypeptide (VIP)-positive profiles that persisted, and AChE- and CGRP-positive profiles and cells that also persisted but had a different distribution to VIP-positive fibers. Some functional correlates of thymic innervation are discussed although the subject now needs to be further researched.

  16. Ethanol and blood pressure in rats

    SciTech Connect

    Hatton, D.C.; Edgar, S.; McCarron, D.A. )

    1989-02-09

    Epidemiologists have identified alcohol as a risk factor in hypertension. Attempts to increase blood pressure in rats with chronic alcohol ingestion have met with mixed results. Some investigators have reported increases in blood pressure while others have reported decreases. Most investigators have given alcohol in the drinking water which produced differences in food intake across groups. To control for food intake, Wister rats were simultaneously pair fed a liquid diet with either ethanol as 35% of calories or a control diet using ARF/Israel pair-feeding devices. At 5 weeks of age, animals on ethanol diets had lower systolic blood pressure than control animals (145 (n-19) vs. 121 (n-19) mmHg). There was no difference in weight between ethanol and control animals. The same pattern of results was apparent at 7 weeks (143 (n-13) vs. 119 (n-13) mmHg) and 9 weeks (147 (n-7) vs. 124 (n-7)). The data indicate that ethanol produces hypotension in rats when food intake is controlled.

  17. Curt Richter and the female rat.

    PubMed

    Geary, Nori

    2007-09-01

    Richter fully appreciated the fundamental biological importance of sex differences, in particular the challenges of female reproductive function to the two classes of behavior that most engaged him, endogenous rhythms and "self-regulatory" behaviors. Indeed, his contributions in these areas justify honoring him as one of the founders of behavioral neuroendocrinology. During the 1920s Richter, together with Wang, Kinder and other students, performed elegant phenomenological and mechanistic studies of sex differences in rats' spontaneous locomotor activity, nest building, and food intake. All of these behaviors display rhythms entrained to the ovarian cycle in female rats, and Richter's analyses of them formed the bases of many current areas of behavioral neuroscience. Slightly later, Richter made fundamentally important discoveries related to nutrient self-selection in pregnant and lactating rats, including changes in micronutrient and macronutrient selection. These data played a major role in the development of his concept of behavioral regulation of homeostasis. Unfortunately, some of these discoveries are rarely recalled. This is both historically regrettable and potentially an impediment to contemporary research progress.

  18. Laser scattering by transcranial rat brain illumination

    NASA Astrophysics Data System (ADS)

    Sousa, Marcelo V. P.; Prates, Renato; Kato, Ilka T.; Sabino, Caetano P.; Suzuki, Luis C.; Ribeiro, Martha S.; Yoshimura, Elisabeth M.

    2012-06-01

    Due to the great number of applications of Low-Level-Laser-Therapy (LLLT) in Central Nervous System (CNS), the study of light penetration through skull and distribution in the brain becomes extremely important. The aim is to analyze the possibility of precise illumination of deep regions of the rat brain, measure the penetration and distribution of red (λ = 660 nm) and Near Infra-Red (NIR) (λ = 808 nm) diode laser light and compare optical properties of brain structures. The head of the animal (Rattus Novergicus) was epilated and divided by a sagittal cut, 2.3 mm away from mid plane. This section of rat's head was illuminated with red and NIR lasers in points above three anatomical structures: hippocampus, cerebellum and frontal cortex. A high resolution camera, perpendicularly positioned, was used to obtain images of the brain structures. Profiles of scattered intensities in the laser direction were obtained from the images. There is a peak in the scattered light profile corresponding to the skin layer. The bone layer gives rise to a valley in the profile indicating low scattering coefficient, or frontal scattering. Another peak in the region related to the brain is an indication of high scattering coefficient (μs) for this tissue. This work corroborates the use of transcranial LLLT in studies with rats which are subjected to models of CNS diseases. The outcomes of this study point to the possibility of transcranial LLLT in humans for a large number of diseases.

  19. Histomorphometric study on growing condyle of rat.

    PubMed

    Suzuki, S

    1986-03-01

    The purpose of this study was to carry out the histomorphometric assay on the mandibular condylar tissue of the growing rats. Male rats of the Wistar strain at the age of 3, 4, 6, 8 and 10 weeks were used. All rats were injected intravenously with tetracycline and calcein, respectively. They were killed 12 hours after calcein injection. Before embedding in acrylic resin, 3 reference points were marked directly on each condyle to establish the reference plane for the histomorphometry on the ground section. After preparing the ground section, the growth rate of the condyle was obtained by measuring the distance of the two different fluorescent labeling lines. Furthermore, the age-related changes of the relative distribution of the bone, calcified cartilage and prebone (uncalcified bone matrix) were measured under a light microscope by using a grid on the eyepiece reticle. The number of osteoblasts and osteoclasts were also calculated in the same specimen. The following results were obtained: The thickness of the cartilaginous layer and the growth rate of the endochondral bone formation decreased with age. The relative ratio of the bone area in the subchondral tissue increased constantly with age. PMID:3457644

  20. Growth hormone aggregates in the rat adenohypophysis

    NASA Technical Reports Server (NTRS)

    Farrington, M.; Hymer, W. C.

    1990-01-01

    Although it has been known for some time that GH aggregates are contained within the rat anterior pituitary gland, the role that they might play in pituitary function is unknown. The present study examines this issue using the technique of Western blotting, which permitted visualization of 11 GH variants with apparent mol wt ranging from 14-88K. Electroelution of the higher mol wt variants from gels followed by their chemical reduction with beta-mercaptoethanol increased GH immunoassayability by about 5-fold. With the blot procedure we found 1) that GH aggregates greater than 44K were associated with a 40,000 x g sedimentable fraction; 2) that GH aggregates were not present in glands from thyroidectomized rats, but were in glands from the thyroidectomized rats injected with T4; 3) that GH aggregates were uniquely associated with a heavily granulated somatotroph subpopulation isolated by density gradient centrifugation; and 4) that high mol wt GH forms were released from the dense somatotrophs in culture, since treatment of the culture medium with beta-mercaptoethanol increased GH immunoassayability by about 5-fold. Taken together, the results show that high mol wt GH aggregates are contained in secretory granules of certain somatotrophs and are also released in aggregate form from these cells in vitro.

  1. [Intestinal absorption kinetics of flurbiprofen in rats].

    PubMed

    Peng, Jun-Jie; Lin, Cong-Cong; Li, Jiang; Zhu, Zhi-Hong; Yang, Xing-Gang; Pan, Wei-San

    2013-03-01

    To study the in situ intestinal absorption kinetics of flrubiprofen in rats, the absorption of flurbiprofen in small intestine (duodenum, jejunum and ileum) and colon of rats was investigated using in situ single-pass perfusion method and the drug content was measured by HPLC. The effects of drug concentration on the intestinal absorption were investigated. The K(a) and P(app) values of flurbiprofen in the small intestine and colon had no significant difference (P > 0.05). Drug concentration (4.0, 10.0 and 16.0 mg x L(-1)) had no significant influence on the K(a) values (P > 0.05). However, when concentration was 4.0 mg x L(-1) and 10.0 mg x L(-1), significant effect on the P(app) values (P < 0.05) was found, but significant effect on the P(app) values was not shown between 10.0 mg x L(-1) and 16.0 mg x L(-1) (P > 0.05). The K(a) and P(app) values of flurbiprofen on the perfusion flow rate had significant difference (P < 0.05). Flurbiprofen could be absorbed at all segments of the intestine in rats and had no special absorption window. The absorption of flurbiprofen complies with the facilitated diffusion in the general intestinal segments, and accompany with the cytopsistransport mechanism probably. The perfusion flow rate had significant effect on the K(a) and P(app).

  2. Resveratrol Pretreatment Ameliorates TNBS Colitis in Rats

    PubMed Central

    Yildiz, Gulserap; Yildiz, Yuksel; Ulutas, Pinar A.; Yaylali, Aslı; Ural, Muruvvet

    2015-01-01

    Inflammatory bowel disease (IBD) is a chronic intestinal inflammatory disease in humans constituting a major health concern today whose prevalence has been increasing over the world. Production of reactive oxygen species (ROS) and disturbed capacity of antioxidant defense in IBD subjects have been reported. Antioxidants may play a significant role in IBD treatment. This study aimed at evaluating ameliorative effects of intraperitoneal resveratrol pretreatment on trinitrobenzene sulphonic acid (TNBS)-induced colitis in rats. Thirty five Wistar-Albino female rats were divided equally into five groups. Inflammation was induced by the intrarectal administration of TNBS under anesthesia. Intraperitoneal administration of resveratrol (RSV) at a concentration of 10mg/kg/day for 5 days before the induction of colitis significantly reduced microscopy score and malondialdehyde (MDA) levels and increased glutathione peroxidase (GSH Px) activity compared to TNBS and vehicle groups. Also an insignificant increase in catalase (CAT) activity was observed in the RSV treated group compared to TNBS and vehicle groups. In this paper, the most recent patent on the identification and treatment of IBD was indicated. In conclusion, antioxidant RSV proved to have a beneficial effect on TNBS colitis in rats. In light of these advantageous results, the RSV can be considered as adjuvant agent in IBD treatments. PMID:26246013

  3. Metabolism of [6]-gingerol in rats.

    PubMed

    Nakazawa, Takahiro; Ohsawa, Keisuke

    2002-03-22

    The metabolic fate of [6]-gingerol, one of the active constituents of Zingiber officinale Roscoe, was investigated using rats. The bile of rats orally administered [6]-gingerol was shown to contain a major metabolite (1) by HPLC analysis. Although the metabolites derived from [6]-gingerol were not detected in the urine, the ethyl acetate extract of the urine after enzymatic hydrolysis was shown to contain six minor metabolites (2-7). Their structures were determined to be (S)-[6]-gingerol-4'-O-beta-glucuronide (1), vanillic acid (2), ferulic acid (3), (S)-(+)-4-hydroxy-6-oxo-8-(4-hydroxy-3-methoxyphenyl) octanoic acid (4), 4-(4-hydroxy-3-methoxyphenyl)butanoic acid (5), 9-hydroxy [6]-gingerol (6) and (S)-(+)-[6]-gingerol (7) based on spectroscopic and chemical data. The total cumulative amount of 1 excreted in the bile and 2-7 in the urine during 60 h after the oral administration of [6]-gingerol were approximately 48% and 16% of the dose, respectively. The excretion of 2-7 in the urine decreased after gut sterilization. On the other hand, the incubations of [6]-gingerol with rat liver showed the presence of 9-hydroxy [6]-gingerol, gingerdiol (8), and (S)-[6]-gingerol-4'-O-beta-glucuronide (1). These findings suggest that the gut flora and enzymes in the liver play an important part in the metabolism of [6]-gingerol. PMID:12002808

  4. Anandamide mediates cognitive judgement bias in rats.

    PubMed

    Kregiel, J; Malek, N; Popik, P; Starowicz, K; Rygula, R

    2016-02-01

    In the present study, we investigated the effects of acute pharmacological manipulation of the endocannabinoid (EC) system on the valence of cognitive judgement bias of rats in the ambiguous-cue interpretation (ACI) paradigm. To accomplish this goal, after initial behavioural training, different groups of rats received single, systemic injections of the irreversible anandamide (AEA) hydrolysis inhibitor URB597, the cannabinoid receptor type 1 (CB1) inverse agonist AM251, the cannabinoid receptor type 2 (CB2) inverse agonist AM630, the combination of URB597 and AM251, and a combination of URB597 and AM630 and were subsequently tested with the ACI paradigm. We report that URB597 at a dose of 1 mg/kg significantly biased animals towards positive interpretation of the ambiguous cue and that this effect was abolished by pre-treatment with AM251 (1 mg/kg) or AM630 (1 mg/kg). The CB1 and CB2 inverse agonists administered alone (1 mg/kg) had no statistically significant effects on the interpretation of the ambiguous cue by rats. Our findings suggest involvement of the endocannabinoid system in the mediation of optimistic judgement bias.

  5. Subacute toxicity assessment of annatto in rat.

    PubMed

    Bautista, A R P L; Moreira, E L T; Batista, M S; Miranda, M S; Gomes, I C S

    2004-04-01

    Increased human use of annatto (Bixa orellana L), a red yellow food colorant, demands generation of toxicity data. The toxic effects of annatto powder (bixin 27%) have been assessed following administration of a subacute regimen (4 weeks, 20 doses) in Wistar male and female rats. A full study with three dose levels was considered unnecessary since no sign of toxicity had been noted in a preliminary experiment with 1000 mg/kg body weight/day as was recommended by the OECD guideline. In this study, annatto administered by gavage at a dose level of 2000 mg/kg/day decreased male body weight gain, but had no effect on either food intake or food conversion efficiency. Haematological and plasma biochemical examination as well necropsy performed at the end of administration (29th day) and observation (43rd day) periods revealed no alterations related with annatto administration. Kidney apoptosis occurred in 20% treated female rats in restricted areas without proliferation or tubular segments modification. The precise nature of apoptosis was not investigated in the present study. These findings suggest that annatto was no toxic to the rat. PMID:15019187

  6. Vascularized tail bone grafts in rats.

    PubMed

    Sempuku, T; Tamai, S; Mizumoto, S; Yajima, H

    1993-03-01

    A new experimental model for vascularized corticocancellous bone grafts was established by investigation of vascular anatomy of the tail in 15 adult Fischer 344 rats and determination of the viability of vascularized tail bone grafts into the abdominal wall in 22 7-week-old rats. The tail bones of 40 rats were then raised on the pedicle of the caudal artery and its venae comitantes, transferred to a resected portion in the femur, and observed for 16 weeks. The vascularized graft showed marked reactive periosteal bone formation during the first and second weeks following transfer, and thereafter, the graft continued to show active bone formation. In transverse section, the sharp processes became rounded. In the cancellous bone, both bone resorption and bone formation were noticeably activated early after transfer, although resorption predominated and the amount of the cancellous bone consequently diminished. The nonvascularized grafts showed "creeping substitution." The results suggest that morphologic adaptation occurs if living (i.e., vascularized) tail bones are transferred to long-bone femurs.

  7. Effects of optimism on motivation in rats.

    PubMed

    Rygula, Rafal; Golebiowska, Joanna; Kregiel, Jakub; Kubik, Jakub; Popik, Piotr

    2015-01-01

    In humans, optimism is a cognitive construct related to motivation; optimists exert effort, whereas pessimists disengage from effort. In this study, using a recently developed ambiguous-cue interpretation (ACI) paradigm we took the unique opportunity to investigate whether "optimism" as a trait is correlated with motivation in rodents. In a series of ACI tests (cognitive bias screening, CBS), we identified rats displaying "pessimistic" and "optimistic" traits. Subsequently, we investigated the trait differences in the motivation of these rats to gain reward and to avoid punishment using a progressive ratio (PR) schedule of reinforcement paradigm. Although "optimistic" and "pessimistic" animals did not differ in their motivation to avoid punishment, the "optimistic" rats were significantly more motivated to gain reward than their "pessimistic" conspecifics. For the first time, we showed an association between cognitive judgment bias and motivation in an animal model. Because both investigated processes are closely related to mental health and wellbeing, our results may be valuable for preclinical modeling of many psychiatric disorders. PMID:25762910

  8. Homologous recombination in rat germline stem cells.

    PubMed

    Kanatsu-Shinohara, Mito; Kato-Itoh, Megumi; Ikawa, Masahito; Takehashi, Masanori; Sanbo, Makoto; Morioka, Yuka; Tanaka, Takashi; Morimoto, Hiroko; Hirabayashi, Masumi; Shinohara, Takashi

    2011-07-01

    Spermatogonial stem cells (SSCs) are the only stem cells in the body with germline potential, which makes them an attractive target for germline modification. We previously showed the feasibility of homologous recombination in mouse SSCs and produced knockout (KO) mice by exploiting germline stem (GS) cells, i.e., cultured spermatogonia with SSC activity. In this study, we report the successful homologous recombination in rat GS cells, which can be readily established by their ability to form germ cell colonies on culture plates whose surfaces are hydrophilic and neutrally charged and thus limit somatic cell binding. We established a drug selection protocol for GS cells under hypoxic conditions. The frequency of the homologous recombination of the Ocln gene was 4.2% (2 out of 48 clones). However, these GS cell lines failed to produce offspring following xenogeneic transplantation into mouse testes and microinsemination, suggesting that long-term culture and drug selection have a negative effect on GS cells. Nevertheless, our results demonstrate the feasibility of gene targeting in rat GS cells and pave the way toward the generation of KO rats.

  9. Breathing in Parkinsonism in the Rat.

    PubMed

    Bialkowska, Monika; Boguszewski, Paweł; Pokorski, Mieczyslaw

    2016-01-01

    Parkinsonism is underlain by dopamine (DA) deficiency in the mid-brain, a neurotransmitter innately involved with respiratory regulation. However, the state of respiration in parkinsonism is an unsettled issue. In this study we seek to determine ventilation and its responses to hypoxia in a reserpine--alpha-methyl-tyrosine model of parkinsonism in the rat. We also attempted to differentiate between the role of discrete brain and carotid body DA stores in the modulation of the hypoxic ventilatory response (HVR). To this end we used domperidone, a peripheral D2 receptor antagonist, and levodopa, a central D2 receptor agonist. The HVRs to acute 12% and 8% hypoxia were studied in a whole body plethysmograph in the same rats before and after the induction of parkinsonic symptoms in conscious rats. We found that resting ventilation and the HVR were distinctly reduced in parkinsonism. The reduction was particularly evident in the peak hypoxic hyperpneic augmentation. Domperidone, which enhanced ventilation in the control healthy condition, failed to reverse the reduced parkinsonic HVR. In contrast, levodopa, which did not appreciably affected ventilation in the healthy condition, caused the parkinsonic HVR to return to and above the baseline healthy level. The findings demonstrate the predominance of a lack of the central DA stimulatory element and minimize the role of carotid body DA in the ventilatory impediment of parkinsonism. In conclusion, the study provides the pathophysiological savvy concerning the respiratory insufficiency of parkinsonism, a sequela which carries a risk of chronically impaired blood oxygenation, which may drive the disease worsening.

  10. Rat hepatitis E virus derived from wild rats (Rattus rattus) propagates efficiently in human hepatoma cell lines.

    PubMed

    Jirintai, Suljid; Tanggis; Mulyanto; Suparyatmo, Joseph Benedictus; Takahashi, Masaharu; Kobayashi, Tominari; Nagashima, Shigeo; Nishizawa, Tsutomu; Okamoto, Hiroaki

    2014-06-24

    Although rat hepatitis E virus (HEV) has been identified in wild rats, no cell culture systems for this virus have been established. A recent report suggesting the presence of antibodies against rat HEV in human sera encouraged us to cultivate rat HEV in human cells. When liver homogenates obtained from wild rats (Rattus rattus) in Indonesia were inoculated onto human hepatocarcinoma cells, the rat HEV replicated efficiently in PLC/PRF/5, HuH-7 and HepG2 cells, irrespective of its genetic group (G1-G3). The rat HEV particles released from cultured cells harbored lipid-associated membranes on their surface that were depleted by treatment with detergent and protease, with the buoyant density in sucrose shifting from 1.15-1.16 g/ml to 1.27-1.28 g/ml. A Northern blotting analysis revealed genomic RNA of 7.0 kb and subgenomic RNA of 2.0 kb in the infected cells. The subgenomic RNA of G1-G3 each possessed the extreme 5'-end sequence of GUAGC (nt 4933-4937), downstream of the highly conserved sequence of GAAUAACA (nt 4916-4923). The establishment of culture systems for rat HEV would allow for extended studies of the mechanisms of viral replication and functional roles of HEV proteins. Further investigation is required to clarify the zoonotic potential of rat HEV.

  11. Acoustic noise improves motor learning in spontaneously hypertensive rats, a rat model of attention deficit hyperactivity disorder.

    PubMed

    Söderlund, Göran B W; Eckernäs, Daniel; Holmblad, Olof; Bergquist, Filip

    2015-03-01

    The spontaneously hypertensive (SH) rat model of ADHD displays impaired motor learning. We used this characteristic to study if the recently described acoustic noise benefit in learning in children with ADHD is also observed in the SH rat model. SH rats and a Wistar control strain were trained in skilled reach and rotarod running under either ambient noise or in 75 dBA white noise. In other animals the effect of methylphenidate (MPH) on motor learning was assessed with the same paradigms. To determine if acoustic noise influenced spontaneous motor activity, the effect of acoustic noise was also determined in the open field activity paradigm. We confirm impaired motor learning in the SH rat compared to Wistar SCA controls. Acoustic noise restored motor learning in SH rats learning the Montoya reach test and the rotarod test, but had no influence on learning in Wistar rats. Noise had no effect on open field activity in SH rats, but increased corner time in Wistar. MPH completely restored rotarod learning and performance but did not improve skilled reach in the SH rat. It is suggested that the acoustic noise benefit previously reported in children with ADHD is shared by the SH rat model of ADHD, and the effect is in the same range as that of stimulant treatment. Acoustic noise may be useful as a non-pharmacological alternative to stimulant medication in the treatment of ADHD.

  12. Rickettsial pathogens in the tropical rat mite Ornithonyssus bacoti (Acari: Macronyssidae) from Egyptian rats (Rattus spp.).

    PubMed

    Reeves, Will K; Loftis, Amanda D; Szumlas, Daniel E; Abbassy, Magda M; Helmy, Ibrahim M; Hanafi, Hanafi A; Dasch, Gregory A

    2007-01-01

    We collected and tested 616 tropical rat mites (Ornithonyssus bacoti (Hirst)) from rats (Rattus norvegicus (Berkenhout) and R. rattus (Linnaeus)) throughout 14 governorates in Egypt and tested DNA extracts from pools of these mites for Bartonella spp., Coxiella burnetii, and Rickettsia spp. by PCR amplification and sequencing. Three different mite-associated bacterial agents, including one Bartonella and two Rickettsia spp., were detected in eight pools of mites. Further research could demonstrate the vector potential of mites and pathogenicity of these agents to humans or animals. PMID:17225079

  13. Autoimmune effects of hexachlorobenzene in the rat.

    PubMed

    Schielen, P; Schoo, W; Tekstra, J; Oostermeijer, H H; Seinen, W; Bloksma, N

    1993-10-01

    We investigated whether autoimmune disregulation underlies the formerly reported induction of IgM hypergammaglobulinemia and lymphoid organ enlargement by hexachlorobenzene (HCB) in rats. To this end blood, liver, and lymphoid organs were collected from male Wistar rats after feeding a semisynthetic diet containing 0, 500, or 1000 mg HCB/kg for 3 weeks. Sera prepared from the blood were analyzed for total and (auto)antigen-specific antibody levels by ELISA, organs were weighed, and spleens were further investigated morphologically using immunohistochemically stained cryosections. Present experiments confirmed the ability of HCB to increase total IgM, but not IgG, levels and to increase relative spleen, lymph node, and liver weights. HCB treatment elevated IgM, but not IgG, levels against single-stranded DNA, native DNA, rat IgG (representing rheumatoid factor), and bromelain-treated mouse erythrocytes that expose phosphatidylcholine as a major autoantigen. Antibody levels against the foreign antigens sheep erythrocytes, tetanus toxoid, and bovine serum albumin remained unaffected. The IgM autoantibodies proved to be polyreactive. Morphometric analysis of spleen sections showed that HCB caused a proportionally equal expansion of all splenic compartments, but when individual spleen weights were taken into account a significantly larger expansion of the predominantly B cell-containing marginal zones could be noted. The latter compartment also contained an increased number of macrophages that can be recognized by the monoclonal antibody ED3. The ability of HCB to elevate serum antibody levels against autoantigens, but not foreign antigens, indicates that HCB probably does not act by polyclonal B cell activation. The IgM isotype, the repertoire, and the polyreactivity of the serum autoantibodies suggest that HCB activates a recently described B cell subset shown to be committed to the production of these autoantibodies and associated with various systemic autoimmune

  14. The effect of dietary pyridoxine on arsenic deprivation in rats

    SciTech Connect

    Uthus, E.O.; Poelllot, R. )

    1991-03-15

    In experiments on As deprivation, many findings indicate that As can affect enzymes or metabolites that are also influenced by vitamin B{sub 6}. Thus, an experiment was designed to ascertain the effect of pyridoxine (pyr) on As deprivation in rats. Male, weanling rats were fed an amino acid based diet containing 0.24% methionine (M) and less than 15 ng As/g. Dietary variables were As, 0 or 1 {mu}g/g; M, 0 or 3 g/kg; and pyridoxine, 0 or 10 mg/kg. After 10 weeks, growth was reduced by As, Pyr, or M deprivation. Both endogenous ({minus}PP) and pyridoxal phosphate-stimulated (+PP) RBC aspartate aminotransferase were decreased by Pyr deficiency. The ratio of +PP/{minus}PP, known as the activation coefficient (AC), was affected by an interaction between As and Pyr. Pyr deficiency resulted in a less marked increase in AC in the As-deprived rats than in the As-supplemented rats. Plasma Fe was slightly decreased by Pyr deficiency in the As-deprived rats but increased by Pyr deficiency in the As-supplemented rats. Plasma threonine and serine were increased by As supplementation in the Pyr-deficient rats but there was no effect of As supplementation in the Pyr-supplemented rats. Plasma alanine was decreased by As or Pyr deprivation. In Pyr deficiency, As deprivation had no effect on plasma glycine (G) in the M-deficient rats but decreased G in the M-supplemented rats. In the Pyr-supplemented rats, As had no effect on G, regardless of M. The findings indicate that As and Pyr interact to affect amino acid metabolism.

  15. Characterization of Rat Meibomian Gland Ion and Fluid Transport

    PubMed Central

    Yu, Dongfang; Davis, Richard M.; Aita, Megumi; Burns, Kimberlie A.; Clapp, Phillip W.; Gilmore, Rodney C.; Chua, Michael; O'Neal, Wanda K.; Schlegel, Richard; Randell, Scott H.; C. Boucher, Richard

    2016-01-01

    Purpose We establish novel primary rat meibomian gland (MG) cell culture systems and explore the ion transport activities of the rat MG. Methods Freshly excised rat MG tissues were characterized as follows: (1) mRNA expression of selected epithelial ion channels/transporters were measured by RT-PCR, (2) localization of epithelial sodium channel (ENaC) mRNAs was performed by in situ hybridization, and (3) protein expression and localization of βENaC, the Na+/K+/Cl− cotransporter (NKCC), and the Na+/K+ ATPase were evaluated by immunofluorescence. Primary isolated rat MG cells were cocultured with 3T3 feeder cells and a Rho-associated kinase (ROCK) inhibitor (Y-27632) for expansion. Passaged rat MG cells were cultured as planar sheets under air-liquid interface (ALI) conditions for gene expression and electrophysiologic studies. Passaged rat MG cells also were cultured in matrigel matrices to form spheroids, which were examined ultrastructurally by transmission electron microscopy (TEM) and functionally using swelling assays. Results Expression of multiple ion channel/transporter genes was detected in rat MG tissues. β-ENaC mRNA and protein were localized more to MG peripheral acinar cells than central acinar cells or ductular epithelial cells. Electrophysiologic studies of rat MG cell planar cultures demonstrated functional sodium, chloride, and potassium channels, and cotransporters activities. Transmission electron microscopic analyses of rat MG spheroids revealed highly differentiated MG cells with abundant lysosomal lamellar bodies. Rat MG spheroids culture-based measurements demonstrated active volume regulation by ion channels. Conclusions This study demonstrates the presence and function of ion channels and volume transport by rat MG. Two novel primary MG cell culture models that may be useful for MG research were established. PMID:27127933

  16. Impaired NaCl taste thresholds in Zn deprived rats

    SciTech Connect

    Brosvic, G.M.; Slotnick, B.M.; Nelson, N.; Henkin, R.I.

    1986-03-05

    Zn deficiency is a relatively common cause of loss of taste acuity in humans. In some patients replacement with exogenous Zn results in rapid reversal of the loss whereas in others prolonged treatment is needed to restore normal taste function. To study this 300 gm outbred Sprague Dawley rats were given Zn deficient diet (< 1 ppm Zn) supplemented with Zn in drinking water (0.1 gm Zn/100 gm body weight). Rats were trained in an automated operant conditions procedure and NaCl taste thresholds determined. During an initial training period and over two replications mean thresholds were 0.006% and mean plasma Zn was 90 +/- 2 ..mu..g/dl (M +/- SEM) determined by flame atomic absorption spectrophotometry. Rats were then divided into two groups; in one (3 rats) Zn supplement was removed, in the other (4 rats), pair-fed with the former group, Zn supplement was continued. In 10 days NaCl thresholds in Zn deprived rats increased significantly (0.07%, p < 0.01) and in 17 days increased 13 fold (0.08%) but thresholds for pair fed, supplemented rats remained constant (0.006%). There was no overlap in response between any rat in the two groups. Plasma Zn at 17 days in Zn-deprived rats was significantly below pair-fed rats (52 +/- 13 vs 89 +/- 6 ..mu..g/dl, respectively, P < 0.01). At this time Zn-deprived rats were supplemented with Zn for 27 days without any reduction in taste thresholds. These preliminary results are consistent with previous observations in Zn deficient patients.

  17. Involvement of aspartoacylase in tremor expression in rats

    PubMed Central

    Nishitani, Ai; Tanaka, Miyuu; Shimizu, Saki; Kunisawa, Naofumi; Yokoe, Mayuko; Yoshida, Yusaku; Suzuki, Toshiro; Sakuma, Tetsushi; Yamamoto, Takashi; Kuwamura, Mitsuru; Takenaka, Shigeo; Ohno, Yukihiro; Kuramoto, Takashi

    2016-01-01

    Essential tremor (ET) is a common movement disorder with a poorly understood etiology. The TRM/Kyo mutant rat, showing spontaneous tremor, is an animal model of ET. Recently, we demonstrated that tremors in these rats emerge when two mutant loci, a missense mutation in the hyperpolarization-activated cyclic nucleotide-gated potassium channel 1 (Hcn1) and the tremor (tm) deletion, are present simultaneously. However, we did not identify which gene within the tm deletion causes tremor expression in TRM/Kyo rats. A strong candidate among the 13 genes within the tm deletion is aspartoacylase (Aspa), because some Aspa-knockout mouse strains show tremor. Here, we generated Aspa-knockout rats using transcription activator-like effector nuclease technology and produced Aspa/Hcn1 double-mutant rats by crossing Aspa-knockout rats with Hcn1-mutant rats. The Aspa-knockout rats carried nonsense mutations in exon 4; and ASPA proteins were not detectable in their brain extracts. They showed elevated levels of N-acetyl-L-aspartate (NAA) in urine and spongy vacuolation and abnormal myelination in the central nervous system, but no tremor. By contrast, Aspa/Hcn1 double-mutant rats spontaneously showed tremors resembling those in TRM/Kyo rats, and the tremor was suppressed by drugs therapeutic for ET but not for parkinsonian tremor. These findings indicated that the lack of the Aspa gene caused tremor expression in TRM/Kyo rats. Our animal model suggested that the interaction of NAA accumulation due to ASPA deficiency with an unstable neuronal membrane potential caused by HCN1 deficiency was involved in tremor development. PMID:27026062

  18. Intrasplenic transplantation of allogeneic hepatocytes prolongs survival in anhepatic rats.

    PubMed

    Arkadopoulos, N; Lilja, H; Suh, K S; Demetriou, A A; Rozga, J

    1998-11-01

    To examine whether hepatocytes transplanted in the spleen can function as an ectopic liver, we performed hepatocyte transplantation in rats that were rendered anhepatic. Total hepatectomy was performed by using a novel single-stage technique. Following hepatectomy, Group 1 rats (n = 16) were monitored until death to determine survival time without prior intervention. Group 2 anhepatic rats (n = 20) were sacrificed at various times to measure blood hepatocyte growth factor (HGF) and transforming growth factor beta1 (TGF-beta1) levels. Group 3 (n = 16) rats received intrasplenic injection of isolated hepatocytes (2.5 x 10(7) cells/rat) followed by total hepatectomy after 3 days. Group 4 (n = 12) sham-transplanted rats received intrasplenic saline infusion, and after 3 days they were rendered anhepatic. Group 2, 3, and 4 rats were maintained on daily Cyclosporine A (10 mg/kg; intramuscularly). Group 1 anhepatic rats survived for 22.4 +/- 5.2 hours (standard deviation). The anhepatic state was associated with a progressive and statistically significant rise in blood HGF and TGF-beta1 levels. Rats that received hepatocyte transplantation before total hepatectomy had a significantly longer survival time than sham-transplanted anhepatic controls (34.1 +/- 8.5 vs. 15.5 +/- 4.8 hrs, P < .01). Additionally, at 12 hours post-hepatectomy, transplanted rats had significantly lower blood ammonia, prothrombin time, international normalized ratio, and TGF-beta1 levels when compared with sham-transplanted controls. In conclusion, intrasplenic transplantation of allogeneic hepatocytes prolonged survival, improved blood chemistry, and lowered blood TGF-beta1 levels in rats rendered anhepatic. PMID:9794923

  19. Variable reactive hyperemia in normotensive strains of rat.

    PubMed

    Heimlich, J Brett; Pollock, David M

    2014-01-01

    Previous studies from our laboratory report variation in nitric oxide (NO)-dependent arterial pressure within the same strain of normotensive Sprague-Dawley rat dependent upon the commercial vendor supplying the rats. Clinical assessment of endothelial NO activity and endothelial function in general has used postocclusion, flow-mediated dilation (FMD). Therefore, this study was conducted to determine whether the reactive hyperemic response was different between two normotensive strains from two different suppliers, Sprague-Dawley (SD) and Wistar-Kyoto (WKY) rats from Charles River (CR) and Harlan Laboratories (H), respectively. Rats were anesthetized and the femoral artery was occluded for 5 min, with femoral blood flow measured continuously by use of an ultrasonic perivascular flow probe. The average area under the reactive hyperemic response curve (3-min duration) was not different between SD rats from CR (80 ± 23 mL/min∙s; n = 6) and H (94 ± 16 mL/min∙s; n = 6). As previously reported, blood pressures were higher in the SD rats from H versus CR. WKY rats from both suppliers had significantly larger hyperemia; 371 ± 67 versus 281 ± 71 mL/min∙s (n = 5) for the CR and H WKY rats, respectively, but again, were not different between vendors. Blood pressures in WKY rats were similar between vendors. These results suggest that differences in NO bioactivity are not discernable with an adapted FMD protocol in the rat and that normotensive strains of rat can have large differences in reactive hyperemia despite having similar blood pressures.

  20. Changes in the uptake of tritiated estradiol in the hypothalamus and adenohypophysis of old female rats.

    PubMed

    Peng, M T; Peng, Y M

    1973-07-01

    The dysfunction of the hypothalamic-pituitary axis of 32 old female rats was elucidated. Old rats were over 20 months of age; young rats were only several months old. Rats were divided into 3 groups according to vaginal smears and ovarian and uterine findings during laparotomy: 1) prolonged vaginal cornification with polyfollicular ovaries (PVC), 2) anestrus with atropic ovaries and uterus (ANE), and 3) prolonged diestrus with hyperluteinized ovaries and hypertropic uterus (pseudopregnancy, PSP). Even 1 week after ovariectomy the uteri of old rats with PVC (11) or PSP (5) were heavier than the uteri of young adults oq old rats with ANE (20). The pituitaries of young rats (32) were lighter than those of old rats (32). In vitro tritiated estradiol uptakes of anterior hypothalamus, adenohypophysis and uterus of old rats with PVC; anterior and posterior hypothalamus, adenohypophysisand uterus of old rats with ANE (10) and adenohypophysis of old rats with PSP were each significantly lower than the corresponding uptakes in the young rats. Further investigation using young rats with induced PSP, indicated that the decreased tritiated estradiol uptake in the adenohypophysis of old PSP rats was due to old age and unrelated to PSP. In vivo tritiated estradiol uptakes of anterior hypothalamus and adenohypophysis of old rats with PVC or ANE and of uterus of old rats with PVC were significantly lower than the corresponding uptakes in the young rats.

  1. Rat lung phospholipid fatty acid composition in prepregnant, pregnant, and lactating rats: relationship to ozone-induced pulmonary toxicity.

    PubMed

    Gunnison, A F; Finkelstein, I

    1997-01-01

    Our laboratory has demonstrated recently that pulmonary inflammation induced by acute ozone exposure is much more severe in late stage pregnant and lactating rats than in postlactating rats or age-matched virgin females. It is currently widely believed that such pulmonary damage results, at least in part, from the reaction of ozone at sites of unsaturation in phospholipid fatty acid (PLFA) molecules located in the epithelial fluid layer lining the lung surfaces and/or the plasma membranes of epithelial cells underlying this fluid layer. The objective of this study was to compare the PLFA composition of lung tissue and surfactant from ozone-sensitive late stage pregnant and lactating rats with comparable tissue from relatively ozone-insensitive age-matched prepregnant (virgin female) rats to explore the possibility that changes in lung PLFA composition during pregnancy and/or lactation contribute to the enhanced sensitivity of these physiologic states to ozone. In addition, the correlation of changes in plasma PLFA composition with those in lung was investigated. There were minor differences in the composition of lung tissue and surfactant PLFAs between prepregnant rats and pregnant rats at day 17 of gestation and only slightly greater differences between prepregnant and lactating rats. Changes from the prepregnant state in the PLFA composition of lung tissue, but not surfactant, correlated with changes in the plasma only in lactating rats and not in pregnant rats. Overall, the double bond index of PLFAs in surfactant and lung tissue was decreased in pregnant and lactating rats compared with prepregnant rats. Thus, the increased sensitivity of pregnant and lactating rats to ozone-induced lung injury cannot be attributed to an increased availability of unsaturated fatty acids. In addition, the arachidonic acid composition of phospholipids did not appear to explain differences between prepregnant rats and pregnant or lactating rats in their inflammatory response to

  2. Isoproterenol effects evaluated in heart slices of human and rat in comparison to rat heart in vivo

    SciTech Connect

    Herrmann, Julia E.; Heale, Jason; Bieraugel, Mike; Ramos, Meg; Fisher, Robyn L.; Vickers, Alison E.M.

    2014-01-15

    Human response to isoproterenol induced cardiac injury was evaluated by gene and protein pathway changes in human heart slices, and compared to rat heart slices and rat heart in vivo. Isoproterenol (10 and 100 μM) altered human and rat heart slice markers of oxidative stress (ATP and GSH) at 24 h. In this in vivo rat study (0.5 mg/kg), serum troponin concentrations increased with lesion severity, minimal to mild necrosis at 24 and 48 h. In the rat and the human heart, isoproterenol altered pathways for apoptosis/necrosis, stress/energy, inflammation, and remodeling/fibrosis. The rat and human heart slices were in an apoptotic phase, while the in vivo rat heart exhibited necrosis histologically and further progression of tissue remodeling. In human heart slices genes for several heat shock 70 kD members were altered, indicative of stress to mitigate apoptosis. The stress response included alterations in energy utilization, fatty acid processing, and the up-regulation of inducible nitric oxide synthase, a marker of increased oxidative stress in both species. Inflammation markers linked with remodeling included IL-1α, Il-1β, IL-6 and TNFα in both species. Tissue remodeling changes in both species included increases in the TIMP proteins, inhibitors of matrix degradation, the gene/protein of IL-4 linked with cardiac fibrosis, and the gene Ccl7 a chemokine that induces collagen synthesis, and Reg3b a growth factor for cardiac repair. This study demonstrates that the initial human heart slice response to isoproterenol cardiac injury results in apoptosis, stress/energy status, inflammation and tissue remodeling at concentrations similar to that in rat heart slices. - Highlights: • Human response to isoproterenol induced cardiac injury evaluated in heart slices. • Isoproterenol altered apoptosis, energy, inflammation and remodeling pathways. • Human model verified by comparison to rat heart slices and rat heart in vivo. • Human and rat respond to isoproterenol

  3. Geographic Range Expansion for Rat Lungworm in North America

    PubMed Central

    Creecy, James P.; Lord, Wayne D.; Caire, William

    2015-01-01

    Using quantitative PCR analysis and DNA sequencing, we provide evidence for the presence of rat lungworm (Angiostrongylus cantonensis) in Oklahoma, USA, and identified a potentially novel rat host (Sigmodon hispidus). Our results indicate a geographic range expansion for this medically and ecologically relevant parasite in North America. PMID:26079818

  4. Environmental enrichment restores neurogenesis and rapid acquisition in aged rats.

    PubMed

    Speisman, Rachel B; Kumar, Ashok; Rani, Asha; Pastoriza, Jessica M; Severance, Jamie E; Foster, Thomas C; Ormerod, Brandi K

    2013-01-01

    Strategies combatting cognitive decline among the growing aging population are vital. We tested whether environmental enrichment could reverse age-impaired rapid spatial search strategy acquisition concomitantly with hippocampal neurogenesis in rats. Young (5-8 months) and aged (20-22 months) male Fischer 344 rats were pair-housed and exposed to environmental enrichment (n = 7 young, 9 aged) or housed individually (n = 7 young, 7 aged) for 10 weeks. After 5 weeks, hidden platform trials (5 blocks of 3 trials; 15 m inter-block interval), a probe trial, and then visible platform trials (5 blocks of 3 trials; 15 m inter-block interval) commenced in the water maze. One week after testing, rats were given 5 daily intraperitoneal bromodeoxyuridine (50 mg/kg) injections and perfused 4 weeks later to quantify neurogenesis. Although young rats outperformed aged rats, aged enriched rats outperformed aged individually housed rats on all behavioral measures. Neurogenesis decreased with age but enrichment enhanced new cell survival, regardless of age. The novel correlation between new neuron number and behavioral measures obtained in a rapid water maze task among aged rats, suggests that environmental enrichment increases their ability to rapidly acquire and flexibly use spatial information along with neurogenesis.

  5. The Special Status of Actions in Causal Reasoning in Rats

    ERIC Educational Resources Information Center

    Leising, Kenneth J.; Wong, Jared; Waldmann, Michael R.; Blaisdell, Aaron P.

    2008-01-01

    A. P. Blaisdell, K. Sawa, K. J. Leising, and M. R. Waldmann (2006) reported evidence for causal reasoning in rats. After learning through Pavlovian observation that Event A (a light) was a common cause of Events X (an auditory stimulus) and F (food), rats predicted F in the test phase when they observed Event X as a cue but not when they generated…

  6. Increased Expression of Interleukin-18 in Lenses of Ovariectomized Rats.

    PubMed

    Nagai, Noriaki; Ogata, Fumihiko; Kawasaki, Naohito; Ito, Yoshimasa

    2016-01-01

    Previous studies showed an increased prevalence of cataracts in postmenopausal women. In this study, we investigated changes in the levels of calcium ion (Ca(2+)) and interleukin (IL)-18, which are factors in cataract development, in the lenses of ovariectomized (OVX) rats, a model of postmenopausal woman. Although the Ca(2+) content in the blood of OVX rats increased 1 month after ovariectomy and subsequently decreased, the Ca(2+) content in the lenses was unchanged in OVX rats 1-3 months after ovariectomy. The Ca(2+)-ATPase activity in the lenses of OVX rats peaked 1 month after ovariectomy, and the behavior of Ca(2+)-ATPase activity in lenses of OVX rats was similar to that of the Ca(2+) concentration in the blood. It is possible that hypercalcemia increases the Ca(2+) inflow into the lens; however, the enhanced Ca(2+)-ATPase activity prevents the Ca(2+) level from rising. On the other hand, we found that the levels of both IL-18 and interferon (IFN)-γ in the lenses of OVX rats were significantly increased as compared with the lenses of sham (control) rats during the period 1-3 months after surgery. These results suggest that the expression of IFN-γ via IL-18 in the lenses of OVX rats is induced by ovariectomy, and that excessive IL-18 and IFN-γ production in the lenses may be related to cataract development in postmenopausal women. These findings support those of previous studies that assessed lens opacification in postmenopausal women.

  7. Hypercalcemia Leads to Delayed Corneal Wound Healing in Ovariectomized Rats.

    PubMed

    Nagai, Noriaki; Ogata, Fumihiko; Kawasaki, Naohito; Ito, Yoshimasa; Funakami, Yoshinori; Okamoto, Norio; Shimomura, Yoshikazu

    2015-01-01

    Hypercalcemia is often observed in postmenopausal women as well as in patients with primary hyperparathyroidism or malignant tumors. In this study, we investigated the relationship between calcium ion (Ca(2+)) levels in lacrimal fluid and the rate of corneal wound healing in hypercalcemia using ovariectomized (OVX) rat debrided corneal epithelium. We also determined the effects of Ca(2+) levels on cell adhesion, proliferation and viability in a human cornea epithelial cell line (HCE-T). The calcium content in bones of OVX rats decreased after ovariectomy. Moreover, the Ca(2+) content in the blood of OVX rats was increased 1 month after ovariectomy, and decreased. The Ca(2+) content in the lacrimal fluid of OVX rats was also increased after ovariectomy, and then decreased similarly as in blood. Corneal wound healing in OVX rats was delayed in comparison with Sham rats (control rats), and a close relationship was observed between the Ca(2+) levels in lacrimal fluid and the rate of corneal wound healing in Sham and OVX rats (y=-0.7863x+8.785, R=0.78, n=25). In addition, an enhancement in Ca(2+) levels caused a decrease in the viability in HCE-T cells. It is possible that enhanced Ca(2+) levels in lacrimal fluid may cause a decrease in the viability of corneal epithelial cells, resulting in a delay in corneal wound healing. These findings provide significant information that can be used to design further studies aimed at reducing corneal damage of patients with hypercalcemia.

  8. Fix and Sample with Rats in the Dynamics of Choice

    ERIC Educational Resources Information Center

    Aparicio, Carlos F.; Baum, William M.

    2006-01-01

    The generality of the molar view of behavior was extended to the study of choice with rats, showing the usefulness of studying order at various levels of extendedness. Rats' presses on two levers produced food according to concurrent variable-interval variable-interval schedules. Seven different reinforcer ratios were arranged within each session,…

  9. Intelligence-Augmented Rat Cyborgs in Maze Solving.

    PubMed

    Yu, Yipeng; Pan, Gang; Gong, Yongyue; Xu, Kedi; Zheng, Nenggan; Hua, Weidong; Zheng, Xiaoxiang; Wu, Zhaohui

    2016-01-01

    Cyborg intelligence is an emerging kind of intelligence paradigm. It aims to deeply integrate machine intelligence with biological intelligence by connecting machines and living beings via neural interfaces, enhancing strength by combining the biological cognition capability with the machine computational capability. Cyborg intelligence is considered to be a new way to augment living beings with machine intelligence. In this paper, we build rat cyborgs to demonstrate how they can expedite the maze escape task with integration of machine intelligence. We compare the performance of maze solving by computer, by individual rats, and by computer-aided rats (i.e. rat cyborgs). They were asked to find their way from a constant entrance to a constant exit in fourteen diverse mazes. Performance of maze solving was measured by steps, coverage rates, and time spent. The experimental results with six rats and their intelligence-augmented rat cyborgs show that rat cyborgs have the best performance in escaping from mazes. These results provide a proof-of-principle demonstration for cyborg intelligence. In addition, our novel cyborg intelligent system (rat cyborg) has great potential in various applications, such as search and rescue in complex terrains.

  10. Cardiac and thermal homeostasis in the aging Brown Norway rat.

    EPA Science Inventory

    The Brown Norway (BN) rat is a popular strain for aging studies. There is little information on effects of age on baseline cardiac and thermoregulatory parameters in undisturbed BN rats even though cardiac and thermal homeostasis is linked to many pathological deficits in the age...

  11. Composition of Muscle Fiber Types in Rat Rotator Cuff Muscles.

    PubMed

    Rui, Yongjun; Pan, Feng; Mi, Jingyi

    2016-10-01

    The rat is a suitable model to study human rotator cuff pathology owing to the similarities in morphological anatomy structure. However, few studies have reported the composition muscle fiber types of rotator cuff muscles in the rat. In this study, the myosin heavy chain (MyHC) isoforms were stained by immunofluorescence to show the muscle fiber types composition and distribution in rotator cuff muscles of the rat. It was found that rotator cuff muscles in the rat were of mixed fiber type composition. The majority of rotator cuff fibers labeled positively for MyHCII. Moreover, the rat rotator cuff muscles contained hybrid fibers. So, compared with human rotator cuff muscles composed partly of slow-twitch fibers, the majority of fast-twitch fibers in rat rotator cuff muscles should be considered when the rat model study focus on the pathological process of rotator cuff muscles after injury. Gaining greater insight into muscle fiber types in rotator cuff muscles of the rat may contribute to elucidate the mechanism of pathological change in rotator cuff muscles-related diseases. Anat Rec, 299:1397-1401, 2016. © 2016 Wiley Periodicals, Inc.

  12. The Effects of Reinforcer Magnitude on Timing in Rats

    ERIC Educational Resources Information Center

    Ludvig, Elliot A.; Conover, Kent; Shizgal, Peter

    2007-01-01

    The relation between reinforcer magnitude and timing behavior was studied using a peak procedure. Four rats received multiple consecutive sessions with both low and high levels of brain stimulation reward (BSR). Rats paused longer and had later start times during sessions when their responses were reinforced with low-magnitude BSR. When estimated…

  13. Avocado oils and hepatic lipid metabolism in growing rats.

    PubMed

    Werman, M J; Neeman, I; Mokady, S

    1991-02-01

    The effect of various avocado oils on liver metabolism was studied in growing female rats. The rats were fed diets containing 10% (w/w) avocado oil for 4 wk. In comparison with rats fed refined avocado oil obtained from cored fruit by centrifugal separation, rats fed unrefined avocado oil obtained by organic solvent extraction from intact fruit, or its unsaponifiable components, showed a significant increase in total liver lipogenesis as well as in phospholipid and triglceride synthesis. Rats fed avocado-seed oil exhibited enhanced [1-14C]acetate incorporation into total liver lipids but showed the same distribution of label in the three main lipid classes as that of rats fed refined avocado oil. In addition, a significant reduction of triglycerides and protein content of plasma very-low-density lipoprotein and high-density lipoprotein fractions was observed in rats fed avocado-seed oil as compared with rats fed refined oil. Electron micrographs suggested that the alterations in hepatic lipogenesis are related to the marked proliferation of the smooth endoplasmic reticulum, which is known to be associated with induction of enzymes involved with lipid biosynthesis. The differences between the animals fed seed oil and those fed the unrefined oils, in the distribution of label within the main lipid classes, indicate that more than one factor is involved in the alterations caused by these oils.

  14. Rats Depend on Habit Memory for Discrimination Learning and Retention

    ERIC Educational Resources Information Center

    Broadbent, Nicola J.; Squire, Larry R.; Clark, Robert E.

    2007-01-01

    We explored the circumstances in which rats engage either declarative memory (and the hippocampus) or habit memory (and the dorsal striatum). Rats with damage to the hippocampus or dorsal striatum were given three different two-choice discrimination tasks (odor, object, and pattern). These tasks differed in the number of trials required for…

  15. A Rat Excised Larynx Model of Vocal Fold Scar

    ERIC Educational Resources Information Center

    Welham, Nathan V.; Montequin, Douglas W.; Tateya, Ichiro; Tateya, Tomoko; Choi, Seong Hee; Bless, Diane M.

    2009-01-01

    Purpose: To develop and evaluate a rat excised larynx model for the measurement of acoustic, aerodynamic, and vocal fold vibratory changes resulting from vocal fold scar. Method: Twenty-four 4-month-old male Sprague-Dawley rats were assigned to 1 of 4 experimental groups: chronic vocal fold scar, chronic vocal fold scar treated with 100-ng basic…

  16. Using Giant African Pouched Rats ("Cricetomys Gambianus") to Detect Landmines

    ERIC Educational Resources Information Center

    Poling, Alan; Weetjens, Bart J.; Cox, Christophe; Beyene, Negussie W.; Sully, Andrew

    2010-01-01

    Within the past decade, giant pouched rats have been used successfully to detect landmines. This manuscript summarizes how these rats are trained and used operationally. The information provided is intended to be of practical value toward strengthening best practices in using "Cricetomys" for humanitarian purposes while simultaneously ensuring the…

  17. The Diabetic Nephropathy and the Development of Hypertension in Rats

    PubMed Central

    Zuccollo, Adriana; Navarro, Monica

    2001-01-01

    The present study was designed to examine the development of hypertension in diabetic rats treated with streptozotocin (STZ, 1mg/g bw). The rats were studied at 3, 6, 9, 12 and 15 weeks. From the third week the rats were divided in diabetic rats according their glycemias and controls, along 15 weeks. After the third week a group, of rats showed increased urinary protein excretion (93, 134, 155 and 191%) compared to controls. In this group of rats the urinary kallikrein excretion was lower than control and the systolic blood pressure became significantly elevated between 3 and 6 weeks and persisted up to 15 weeks. On the other hand a group of diabetic rats were normotensive with urinary protein excretion similar to controls and urinary kallikrein lower compared to control but significantly higher compared diabetic hypertensive rats. These data suggest that the association of progressive diabetic nephropathy with abnormal endothelium-dependent vasodilation may produce a high prevalence of hypertensive diabetes. PMID:12369707

  18. The Laboratory Rat: Relating Its Age With Human's

    PubMed Central

    Sengupta, Pallav

    2013-01-01

    By late 18th or early 19th century, albino rats became the most commonly used experimental animals in numerous biomedical researches, as they have been recognized as the preeminent model mammalian system. But, the precise correlation between age of laboratory rats and human is still a subject of debate. A number of studies have tried to detect these correlations in various ways, But, have not successfully provided any proper association. Thus, the current review attempts to compare rat and human age at different phases of their life. The overall findings indicate that rats grow rapidly during their childhood and become sexually mature at about the sixth week, but attain social maturity 5-6 months later. In adulthood, every day of the animal is approximately equivalent to 34.8 human days (i.e., one rat month is comparable to three human years). Numerous researchers performed experimental investigations in albino rats and estimated, in general, while considering their entire life span, that a human month resembles every-day life of a laboratory rat. These differences signify the variations in their anatomy, physiology and developmental processes, which must be taken into consideration while analyzing the results or selecting the dose of any research in rats when age is a crucial factor. PMID:23930179

  19. Oral versus postingestive origin of polysaccharide appetite in the rat.

    PubMed

    Sclafani, A; Nissenbaum, J W

    1987-01-01

    Previous studies have revealed that rats consume substantial amounts of polysaccharide solutions, even if the solutions are made bitter with the addition of sucrose octa acetate (SOA). The present experiment used the gastric sham-feeding preparation to determine if it is the orosensory or postingestive properties of polysaccharides that motivate rats to consume polysaccharide (Polycose) solutions. In Experiment 1, food deprived rats sham fed less of a 0.05% SOA + 32% Polycose solution than they did of a 32% glucose solution, but their SOA-Polycose intake was still considerable (44 ml/hr). The same rats refused to sham feed SOA-gum and SOA-sugar solutions that were similar to the SOA-Polycose solution in bitter taste, viscosity and free sugar content. In Experiment 2, rats sham fed as much of a 32% Polycose solution as they did of a 32% sucrose solution. Despite the gastric fistula, some of the ingested Polycose was absorbed as evidenced by an increase in the rats' blood glucose levels. The addition of acarbose, a drug that inhibits polysaccharide digestion, to the Polycose solution blocked the increase in blood glucose, but did not reduce the rats' sham feeding of the solution. These findings indicate that it is the orosensory (presumably taste) properties of polysaccharide solutions, not their postingestive effects, that initially attract rats to the solutions. The results question the assumption that polysaccharides are "tasteless" to animals.

  20. ATRAZINE EFFECTS ON EARLY PREGNANCY AND IMPLANATION IN THE RAT

    EPA Science Inventory

    Atrazine Effects on Early Pregnancy and Implantation in the Rat.
    A.M. Cummings, B.E. Rhodes*, and R.L. Cooper*.
    Reproductive Toxicology Division, NHEERL, USEPA, Research Triangle Park, NC
    Atrazine (ATR), an herbicide, can induce mammary tumors in rats. ATR can also sup...

  1. Differences between brainstem gliomas in juvenile and adult rats

    PubMed Central

    WANG, YU; TIAN, YONGJI; WAN, HONG; LI, DEZHI; WU, WENHAO; YIN, LUXIN; JIANG, JIAN; WAN, WEIQING; ZHANG, LIWEI

    2013-01-01

    Clinical studies have shown that gliomas of the brainstem behave differently in children and adults. The aim of the present study was to compare and analyze the differences between these gliomas in juvenile and adult rats with regard to tumor growth, survival, pathology and magnetic resonance imaging (MRI). A total of 25 juvenile and 25 adult Wistar rats were divided into groups A (15 juvenile rats), B (10 juvenile rats), C (15 adult rats) and D (10 adult rats). The rats of groups A and C (experimental) were injected with glioma cells, while groups B and D (control) were injected with a physiological saline solution. Rat neurological signs, survival time, tumor size, hematoxylin and eosin (HE) staining and immunohistochemical staining for MMP-2, MMP-9 and β-catenin were compared. The survival time of group A was 19.47±2.232 days, whereas that of group C was 21.47±2.232 days (P<0.05). The tumor sizes were 4.55 and 4.62 mm (P>0.05) in groups A and C, respectively. HE and immunohistochemical staining revealed no differences between the groups. The results suggest that the growth patterns and invasiveness of brainstem gliomas may vary in children compared with adults due to the varied biological behaviors of the tumor cells. PMID:23946812

  2. Intelligence-Augmented Rat Cyborgs in Maze Solving

    PubMed Central

    Yu, Yipeng; Pan, Gang; Gong, Yongyue; Xu, Kedi; Zheng, Nenggan; Hua, Weidong; Zheng, Xiaoxiang; Wu, Zhaohui

    2016-01-01

    Cyborg intelligence is an emerging kind of intelligence paradigm. It aims to deeply integrate machine intelligence with biological intelligence by connecting machines and living beings via neural interfaces, enhancing strength by combining the biological cognition capability with the machine computational capability. Cyborg intelligence is considered to be a new way to augment living beings with machine intelligence. In this paper, we build rat cyborgs to demonstrate how they can expedite the maze escape task with integration of machine intelligence. We compare the performance of maze solving by computer, by individual rats, and by computer-aided rats (i.e. rat cyborgs). They were asked to find their way from a constant entrance to a constant exit in fourteen diverse mazes. Performance of maze solving was measured by steps, coverage rates, and time spent. The experimental results with six rats and their intelligence-augmented rat cyborgs show that rat cyborgs have the best performance in escaping from mazes. These results provide a proof-of-principle demonstration for cyborg intelligence. In addition, our novel cyborg intelligent system (rat cyborg) has great potential in various applications, such as search and rescue in complex terrains. PMID:26859299

  3. Intraperitoneal N-acetylcysteine for acute iron intoxication in rats.

    PubMed

    Breitbart, Rachelle; Abu-Kishk, Ibrahim; Kozer, Eran; Ben-Assa, Eyal; Goldstein, Lee H; Youngster, Ilan; Berkovitch, Matitiahu

    2011-10-01

    Free radical formation and release of oxidant agents have been suggested as possible mechanisms for tissue damage in acute iron intoxication. N-acetylcysteine (NAC), a glutathione substitute and an antioxidant, is widely used as an antidote for various intoxications. Our aim was to determine whether intraperitoneal (i.p.) NAC would reduce the mortality of rats after acute, toxic oral doses of iron. Male Wistar rats were studied in three phases. In the first phase, animals were assigned to groups 1 (distilled water by gavage) and 2 (i.p. NAC) and observed for survival. In the second phase, rats were assigned to groups 3 (400 mg/kg elemental iron orally) and 4 (400 mg/kg elemental iron, followed by 150 mg/kg i.p. NAC). Survival was observed. Because most rats in Group 3 died within 90 minutes after iron administration, a third phase was conducted in order to allow for comparison of iron and transaminase serum levels after the administration of iron and NAC (group 5: n = 10). Mortality was significantly lower in rats treated with iron and NAC, compared to those treated with iron (P = 0.016). Median serum iron level was significantly lower among rats treated with iron and NAC, compared with rats treated with iron alone (P = 0.002). In a rat model of acute iron intoxication, i.p. administration of NAC may decrease serum iron levels and mortality. PMID:21740343

  4. Delay Discounting of Qualitatively Different Reinforcers in Rats

    ERIC Educational Resources Information Center

    Calvert, Amanda L.; Green, Leonard; Myerson, Joel

    2010-01-01

    Humans discount larger delayed rewards less steeply than smaller rewards, whereas no such magnitude effect has been observed in rats (and pigeons). It remains possible that rats' discounting is sensitive to differences in the quality of the delayed reinforcer even though it is not sensitive to amount. To evaluate this possibility, Experiment 1…

  5. Effect of chronic hypoxia on penile erectile function in rats.

    PubMed

    Yu, D P; Liu, X H; Wei, A Y

    2015-09-08

    We examined the relationship between chronic hypoxia and erectile dysfunction in rat and its possible pathogenic mechanism. Forty-eight white male adult Sprague-Dawley rats were randomly divided into a test group and a control group. In accordance with the experimental time (2, 6, and 10 weeks), each group was divided into 3 subgroups, with 8 rats in each subgroup. Rats in the test group were fed in an airtight hypoxia cabin, while rats in the control group were maintained in a normal environment, with other conditions kept the same. At 2, 6, and 10 weeks, the rats in each group were observed for erectile function. Affinity purification was used to detect neural nitric oxide synthase (nNOS)-positive nerve fibers and endothelial nitric oxide synthase (eNOS) expression. After hypoxia, erectile frequency decreased significantly compared to before hypoxia (P < 0.001). Comparison of the test group and control group revealed a significant difference in the quantity of nNOS-positive nerve fiber and eNOS protein expression (P < 0.01). Hypoxia may influence erectile function and nNOS and eNOS expression in rats. The decrease in the quantity of nNOS nerve fibers and expression of eNOS may contribute to erectile dysfunction under hypoxic conditions in rats.

  6. Natural killer (NK) cell cytotoxicity in athymic (nude) rats.

    PubMed

    Grzelak, I; Olszewski, W L; Fossum, S; Engeset, A

    1984-01-01

    The in vitro and in vivo natural killer (NK) cell activity of congenitally athymic, nude (ATH) rats and of normal, euthymic (EUTH) rats was compared. We found: a) a higher level of in vitro NK cell activity in blood, spleen and lymph nodes of ATH rats compared with their heterozygous littermates, b) in the spleen the number of NK lytic units per organ was not higher in ATH compared with EUTH whereas it was significantly higher in lymph nodes, c) a lack of age-dependence of in vitro NK cell activity tested in culture with heat inactivated fetal calf serum, d) a higher rate of in vivo elimination of target tumor cells in 4-week ATH rats compared with EUTH rats, e) an age-dependent decrease in the rate of in vivo target cell elimination in both groups, and finally, f) an age-dependent increase in the inhibitory effect of autologous serum on NK cell activity in vitro in both groups. These findings show that the blood and lymphoid organs of athymic rats contain a substantially higher proportion of NK cells, active both in vitro and in vivo against K562 tumor cells, than their euthymic littermates. In the spleen this increased proportion can be attributed to the lack of T cells, whereas in the ATH rat lymph nodes there is an absolute increase in NK cell activity, and that the decrease of cytotoxicity in vivo with age reflects the increasing inhibitory properties of autologous serum both in nude and in normal rats.

  7. Biochemical and histochemical adaptations of skeletal muscle to rat suspension

    NASA Technical Reports Server (NTRS)

    Templeton, G. H.

    1984-01-01

    The influence of rat suspension on soleus disuse and atrophy was investigated to measure changes in fiber area and number and to determine if suspension elicited changes in lysosomal protease activity and rate of calcium uptake by the sarcoplasmic reticulum. The infuence of rat suspension on myosin light chain phosphorylation and succinate dehydrogenase activity are determined.

  8. Leucocyte responses to fighting in the adult male bandicoot rat.

    PubMed

    Ghosh, P R; Sahu, A; Maiti, B R

    1983-01-01

    The effect of fighting stress on blood leucocyte count was studied in the adult male bandicoot rat. Exposure to fighting stress for 3 h induced neutrophilia, eosinopenia, lymphopenia and monocytopenia. The changes were more significant in the subordinate rat than in the dominant animal. It is suggested that leucocyte responses to fighting are perhaps mediated by the adrenal gland in these animals.

  9. CARBONYL SULFIDE INHALATION PRODUCES BRAIN LESIONS IN F344 RATS.

    EPA Science Inventory

    Carbonyl sulfide (COS) is an intermediate in the production of pesticides and herbicides, and is a metabolite of the neurotoxicant carbon disulfide. The potential neurotoxicity of inhaled COS was investigated in F344 rats. Male rats were exposed to 0, 75, 150, 300, or 600 ppm COS...

  10. Rat Genome Database: a unique resource for rat, human, and mouse quantitative trait locus data.

    PubMed

    Nigam, Rajni; Laulederkind, Stanley J F; Hayman, G Thomas; Smith, Jennifer R; Wang, Shur-Jen; Lowry, Timothy F; Petri, Victoria; De Pons, Jeff; Tutaj, Marek; Liu, Weisong; Jayaraman, Pushkala; Munzenmaier, Diane H; Worthey, Elizabeth A; Dwinell, Melinda R; Shimoyama, Mary; Jacob, Howard J

    2013-09-16

    The rat has been widely used as a disease model in a laboratory setting, resulting in an abundance of genetic and phenotype data from a wide variety of studies. These data can be found at the Rat Genome Database (RGD, http://rgd.mcw.edu/), which provides a platform for researchers interested in linking genomic variations to phenotypes. Quantitative trait loci (QTLs) form one of the earliest and core datasets, allowing researchers to identify loci harboring genes associated with disease. These QTLs are not only important for those using the rat to identify genes and regions associated with disease, but also for cross-organism analyses of syntenic regions on the mouse and the human genomes to identify potential regions for study in these organisms. Currently, RGD has data on >1,900 rat QTLs that include details about the methods and animals used to determine the respective QTL along with the genomic positions and markers that define the region. RGD also curates human QTLs (>1,900) and houses>4,000 mouse QTLs (imported from Mouse Genome Informatics). Multiple ontologies are used to standardize traits, phenotypes, diseases, and experimental methods to facilitate queries, analyses, and cross-organism comparisons. QTLs are visualized in tools such as GBrowse and GViewer, with additional tools for analysis of gene sets within QTL regions. The QTL data at RGD provide valuable information for the study of mapped phenotypes and identification of candidate genes for disease associations.

  11. Real-time application of the Rat Grimace Scale as a welfare refinement in laboratory rats

    PubMed Central

    Leung, Vivian; Zhang, Emily; Pang, Daniel SJ

    2016-01-01

    Rodent grimace scales have been recently validated for pain assessment, allowing evaluation of facial expressions associated with pain. The standard scoring method is retrospective, limiting its application beyond pain research. This study aimed to assess if real-time application of the Rat Grimace Scale (RGS) could reliably and accurately assess pain in rats when compared to the standard method. Thirty-two male and female Sprague-Dawley rats were block randomized into three treatment groups: buprenorphine (0.03 mg/kg, subcutaneously), multimodal analgesia (buprenorphine [0.03 mg/kg] and meloxicam [2 mg/kg], subcutaneously), or saline, followed by intra-plantar carrageenan. Real-time observations (interval and point) were compared to the standard RGS method using concurrent video-recordings. Real-time interval observations reflected the results from the standard RGS method by successfully discriminating between analgesia and saline treatments. Real-time point observations showed poor discrimination between treatments. Real-time observations showed minimal bias (<0.1) and acceptable limits of agreement. These results indicate that applying the RGS in real-time through an interval scoring method is feasible and effective, allowing refinement of laboratory rat welfare through rapid identification of pain and early intervention. PMID:27530823

  12. Rat neurosphere cells protect axotomized rat retinal ganglion cells and facilitate their regeneration.

    PubMed

    Hill, Andrew J; Zwart, Isabel; Samaranayake, Asanka Nuwan; Al-Allaf, Faisal; Girdlestone, John; Mehmet, Huseyin; Navarrete, Roberto; Navarrete, Cristina; Jen, Ling-Sun

    2009-07-01

    We investigated the ability of a population of rat neural stem and precursor cells derived from rat embryonic spinal cord to protect injured neurons in the rat central nervous system (CNS). The neonatal rat optic pathway was used as a model of CNS injury, whereby retinal ganglion cells (RGCs) were axotomized by lesion of the lateral geniculate nucleus one day after birth. Neural stem and precursor cells derived from expanded neurospheres (NS) were transplanted into the lesion site at the time of injury. Application of Fast Blue tracer dye to the lesion site demonstrated that significant numbers of RGCs survived at 4 and 8 weeks in animals that received a transplant, with an average of 28% survival, though in some individual cases survival was greater than 50%. No RGCs survived in animals that received a lesion alone. Furthermore, labeled RGCs were also observed when Fast Blue was applied to the superior colliculus (SC) at 4 weeks, suggesting that neurosphere cells also facilitated RGC to regenerate to their normal target. Transplanted cells did not migrate or express neural markers after transplantation, and secreted several neurotrophic factors in vitro. We conclude that NS cells can protect injured CNS neurons and promote their regeneration. These effects are not attributable to cell replacement, and may be mediated via secretion of neurotrophic factors. Thus, neuroprotection by stem cell populations may be a more viable approach for treatment of CNS disorders than cell replacement therapy.

  13. Real-time application of the Rat Grimace Scale as a welfare refinement in laboratory rats.

    PubMed

    Leung, Vivian; Zhang, Emily; Pang, Daniel Sj

    2016-01-01

    Rodent grimace scales have been recently validated for pain assessment, allowing evaluation of facial expressions associated with pain. The standard scoring method is retrospective, limiting its application beyond pain research. This study aimed to assess if real-time application of the Rat Grimace Scale (RGS) could reliably and accurately assess pain in rats when compared to the standard method. Thirty-two male and female Sprague-Dawley rats were block randomized into three treatment groups: buprenorphine (0.03 mg/kg, subcutaneously), multimodal analgesia (buprenorphine [0.03 mg/kg] and meloxicam [2 mg/kg], subcutaneously), or saline, followed by intra-plantar carrageenan. Real-time observations (interval and point) were compared to the standard RGS method using concurrent video-recordings. Real-time interval observations reflected the results from the standard RGS method by successfully discriminating between analgesia and saline treatments. Real-time point observations showed poor discrimination between treatments. Real-time observations showed minimal bias (<0.1) and acceptable limits of agreement. These results indicate that applying the RGS in real-time through an interval scoring method is feasible and effective, allowing refinement of laboratory rat welfare through rapid identification of pain and early intervention. PMID:27530823

  14. Integration of the Rat Recombination and EST Maps in the Rat Genomic Sequence and Comparative Mapping Analysis With the Mouse Genome

    PubMed Central

    Wilder, Steven P.; Bihoreau, Marie-Thérèse; Argoud, Karène; Watanabe, Takeshi K.; Lathrop, Mark; Gauguier, Dominique

    2004-01-01

    Inbred strains of the laboratory rat are widely used for identifying genetic regions involved in the control of complex quantitative phenotypes of biomedical importance. The draft genomic sequence of the rat now provides essential information for annotating rat quantitative trait locus (QTL) maps. Following the survey of unique rat microsatellite (11,585 including 1648 new markers) and EST (10,067) markers currently available, we have incorporated a selection of 7952 rat EST sequences in an improved version of the integrated linkage-radiation hybrid map of the rat containing 2058 microsatellite markers which provided over 10,000 potential anchor points between rat QTL and the genomic sequence of the rat. A total of 996 genetic positions were resolved (avg. spacing 1.77 cM) in a single large intercross and anchored in the rat genomic sequence (avg. spacing 1.62 Mb). Comparative genome maps between rat and mouse were constructed by successful computational alignment of 6108 mapped rat ESTs in the mouse genome. The integration of rat linkage maps in the draft genomic sequence of the rat and that of other species represents an essential step for translating rat QTL intervals into human chromosomal targets. PMID:15060020

  15. Response to novelty in the laboratory Wistar rat, wild-captive WWCPS rat, and the gray short-tailed opossum (Monodelphis domestica).

    PubMed

    Pisula, Wojciech; Turlejski, Krzysztof; Stryjek, Rafał; Nałęcz-Tolak, Aleksandra; Grabiec, Marta; Djavadian, Rouzanna L

    2012-10-01

    Behavior of the laboratory gray short-tailed opossums (Monodelphis domestica), Warsaw Wild Captive Pisula Stryjek rats (WWCPS) and laboratory rats (Wistar) has been registered in the period of familiarization with a new environment and consecutive confrontation with a novel, innocuous object placed in that familiarized environment. In the new environment the sequence of anxiety, investigation, and habituation was shortest in the opossum, longer in the laboratory rat and longest in the WWCPS rat. When placed in it, gray short-tailed opossums investigated the new environment with the shortest delay and most intensity. In reaction to novel objects, opossums and laboratory rats prolonged the time spent in the proximity of the new object, while the WWCPS rat did not show that reaction. Both opossums and laboratory rats increased the number of contacts with the new object, whereas WWCPS rats reduced those contacts. Behavior of all three species and lines grouped in different clusters. Some other quantitative and qualitative differences in behavior of the investigated animals are also described, showing a higher level of anxiety in both lines of rats than in the opossum. Behavioral differences between species and lines of animals used in this study may be attributed to different ecological adaptations of rats and opossums and to the effect of domestication in the laboratory rats. These behavioral differences make comparisons of opossums vs rat, and wild rat vs laboratory rat interesting models for studying the brain mechanisms of anxiety and neotic motivations.

  16. High alcohol intake in female Sardinian alcohol-preferring rats.

    PubMed

    Loi, Barbara; Colombo, Giancarlo; Maccioni, Paola; Carai, Mauro A M; Franconi, Flavia; Gessa, Gian Luigi

    2014-06-01

    Sardinian alcohol-preferring (sP) rats have been selectively bred for high alcohol preference and consumption. When exposed to the standard, home cage 2-bottle "alcohol (10%, v/v) vs. water" choice regimen with continuous access, male sP rats consume daily approximately 6 g/kg alcohol. Conversely, when exposed to the intermittent (once every other day) access to 2 bottles containing alcohol (20%, v/v) and water, respectively, male sP rats display marked increases in daily alcohol intake and signs of alcohol intoxication and "behavioral" dependence. The present study was designed to assess alcohol intake in female sP rats exposed, under the 2-bottle choice regimen, to (a) 10% (v/v) alcohol with continuous access (CA10%), (b) 10% (v/v) alcohol with intermittent access (IA10%), (c) 20% (v/v) alcohol with continuous access (CA20%), and (d) 20% (v/v) alcohol with intermittent access (IA20%). Male sP rats (exposed to CA10% and IA20% conditions) were included for comparison. Over 20 daily drinking sessions, daily alcohol intake in female CA10% and IA20% rats averaged 7.0 and 9.6 g/kg, respectively. The rank of alcohol intake was IA20% > IA10% = CA20% > CA10%. Conversely, daily alcohol intake in male CA10% and IA20% rats averaged 6.0 and 8.2 g/kg, respectively. Comparison of female and male rats yielded the following rank of alcohol intake: female IA20% > male IA20% > female CA10% ≥ male CA10%. An additional experiment found that alcohol drinking during the first hour of the drinking session produced mean blood alcohol levels of 35-40 mg% and 85-100 mg% in the CA10% and IA20% rats, respectively. These results (a) extend to female sP rats previous data demonstrating the capacity of the IA20% condition to markedly escalate alcohol drinking, and (b) demonstrate that female sP rats consume more alcohol than male sP rats. This sex difference is more evident under the IA20% condition, suggesting that female sP rats are highly sensitive to the promoting effect

  17. Calcium balance in mature male rats with unloaded hindlimbs

    NASA Technical Reports Server (NTRS)

    Navidi, Meena; Evans, Juliann; Wolinsky, Ira; Arnaud, Sara B.

    2004-01-01

    BACKGROUND: Calcium balances, regulated by the calcium endocrine system, are negative during spaceflight but have not been reported in flight simulation models using fully mature small animals. METHODS: We conducted two calcium (Ca) balance studies in 6-mo-old male rats exposed to a model that unloads the hindlimbs (HU) for 4 wk. Control (C) and HU rats were fed diets with 0.5% Ca in the first and 0.1% Ca in the second study. Housing in metabolic cages enabled daily food and water intake measurements as well as collections of urine and fecal specimens. At necropsy, blood was obtained for measures of Ca-regulating hormones. RESULTS: Both C and HU rats adjusted to housing and diets with decreases in body weight and negative Ca balances during the first week of each experiment. Thereafter, averages of Ca balances were more negative in the unloaded rats than controls: -8.1 vs. -1.6 mg x d(-1) in rats fed 0.5% (p < 0.05). This difference was not due to urinary Ca excretion since it was lower in HU than C rats (1.27 +/- 0.51 mg x d(-1) vs. 2.35 +/- 0.82 mg x d(-1), p < 0.05). Fecal Ca in HU rats exceeded dietary Ca by 4-7%, Restricting dietary Ca to 0.1% was followed by an increase in serum 1,25-dihydroxyvitamin D (1,25-D) and greater intestinal Ca absorption than in rats fed 0.5% Ca. Ca balances in rats fed 0.1% Ca were also more negative in HU than C rats (-2.4 vs. -0.03 mg x d(-1), p < 0.05). Parathyroid hormone (PTH) was suppressed and 1,25-D increased in HU rats fed 0.5% Ca. C rats fed 0.1% Ca had increased PTH and 1,25-D was the same as in the HU group. CONCLUSION: After adaptation, Ca balances were more negative in mature male rats with unloaded hindlimbs than controls, an effect from increased secretion and loss of endogenous fecal Ca associated with increased 1,25-D in Ca-replete and Ca-restricted rats.

  18. Activity-wheel stress and serotonergic hypersensitivity in rats.

    PubMed

    Mayeda, A R; Simon, J R; Hingtgen, J N; Hofstetter, J R; Aprison, M H

    1989-06-01

    Adult male Wistar rats were subjected to activity wheel stress: unlimited access to an activity wheel for up to twelve days and food for 30 to 60 min each day. Each treated rat was paired with a control, the latter being housed in home cages and given sufficient food to maintain a weight similar to the stressed partner. All rats were previously trained on a variable interval schedule for milk reinforcement. When the activity of the stressed rat increased rapidly then decreased suddenly, the pair was decapitated for biochemical analysis. Levels of the serotonin metabolite, 5-hydroxyindoleacetic acid, decreased by 50%, and the Bmax for ketanserin binding increased by 19% in frontal cortical homogenates from the stressed rats when compared to controls. These data support the concept that stress increases the sensitivity of central serotonin receptors. PMID:2479035

  19. Neurotoxic behavioral effects of Lake Ontario salmon diets in rats

    SciTech Connect

    Hertzler, D.R. )

    1990-03-01

    Six experiments were conducted to examine possible neurotoxic effects of the exposure to contaminants in Lake Ontario salmon administered through the diets of rats. Rats were fed different concentrations of fish (8%, 15% or 30%) in one of three diet conditions: Lake Ontario salmon, Pacific Ocean salmon, or laboratory rat chow only. Following 20 days on the diets, rats were tested for five minutes per day in a modified open field for one or three days. Lake Ontario salmon diets consistently produced significantly lower activity, rearing, and nosepoke behaviors in comparison with ocean salmon or rat chow diet conditions. A dose-response effect for concentration of lake salmon was obtained, and the attenuation effect occurred in males, females, adult or young animals, and postweaning females, with fish sampled over a five-year period. While only two of several potential contaminants were tested, both fish and brain analyses of mirex and PCBs relate to the behavioral effects.

  20. Cortical development of the visual system of the rat.

    PubMed

    Prévost, François; Lepore, Franco; Guillemot, Jean-Paul

    2010-01-01

    Although rat is commonly used for studying the visual system, the development of spatio-temporal receptive field properties of neurons in its primary visual cortex remains relatively unknown. Extracellular single neuron recordings were thus carried out in anaesthetized newborn rats between postnatal (P) day 15 and 30 and in adult rats. The first neuronal responses evoked by drifting sinusoidal gratings were obtained at P16. From P27-P30 to adulthood, the neurons' optimal temporal frequency significantly increased, whereas the contrast threshold decreased. However, the optimal spatial frequency, spatial resolution and spatial bandwidth were, soon after eye opening, similar to those observed in the adult rat. The differential maturation of receptive field properties is discussed with regard to the functional pathways of the rat visual system.

  1. Cognitive bias in rats is not influenced by oxytocin

    PubMed Central

    McGuire, Molly C.; Williams, Keith L.; Welling, Lisa L. M.; Vonk, Jennifer

    2015-01-01

    The effect of oxytocin on cognitive bias was investigated in rats in a modified conditioned place preference paradigm. Fifteen male rats were trained to discriminate between two different cue combinations, one paired with palatable foods (reward training), and the other paired with unpalatable food (aversive training). Next, their reactions to two ambiguous cue combinations were evaluated and their latency to contact the goal pot recorded. Rats were injected with either oxytocin (OT) or saline with the prediction that rats administered OT would display a shorter average latency to approach on ambiguous trials. There was no significant difference between latencies to approach on ambiguous trials compared to reward trials, but the rats were significantly slower on the aversive compared to the ambiguous conditions. Oxytocin did not affect approach time; however, it was unclear, after follow-up testing, whether the OT doses tested were sufficient to produce the desired effects on cognitive bias. Future research should consider this possibility. PMID:26388811

  2. Experimental rat models of chronic allograft nephropathy: a review

    PubMed Central

    Shrestha, Badri; Haylor, John

    2014-01-01

    Chronic allograft nephropathy (CAN) is the leading cause of late allograft loss after renal transplantation (RT), which continues to remain an unresolved problem. A rat model of CAN was first described in 1969 by White et al. Although the rat model of RT can be technically challenging, it is attractive because the pathogenesis of CAN is similar to that following human RT and the pathological features of CAN develop within months as compared with years in human RT. The rat model of RT is considered as a useful investigational tool in the field of experimental transplantation research. We have reviewed the literature on studies of rat RT reporting the donor and recipient strain combinations that have investigated resultant survival and histological outcomes. Several different combinations of inbred and outbred rat combinations have been reported to investigate the multiple aspects of transplantation, including acute rejection, cellular and humoral rejection mechanisms and their treatments, CAN, and potential targets for its prevention. PMID:25092995

  3. Microarray analysis of thioacetamide-treated type 1 diabetic rats

    SciTech Connect

    Devi, Sachin S.; Mehendale, Harihara M. . E-mail: mehendale@ulm.edu

    2006-04-01

    It is well known that diabetes imparts high sensitivity to numerous hepatotoxicants. Previously, we have shown that a normally non-lethal dose of thioacetamide (TA, 300 mg/kg) causes 90% mortality in type 1 diabetic (DB) rats due to inhibited tissue repair allowing progression of liver injury. On the other hand, DB rats exposed to 30 mg TA/kg exhibit delayed tissue repair and delayed recovery from injury. The objective of this study was to investigate the mechanism of impaired tissue repair and progression of liver injury in TA-treated DB rats by using cDNA microarray. Gene expression pattern was examined at 0, 6, and 12 h after TA challenge, and selected mechanistic leads from microarray experiments were confirmed by real-time RT-PCR and further investigated at protein level over the time course of 0 to 36 h after TA treatment. Diabetic condition itself increased gene expression of proteases and decreased gene expression of protease inhibitors. Administration of 300 mg TA/kg to DB rats further elevated gene expression of proteases and suppressed gene expression of protease inhibitors, explaining progression of liver injury in DB rats after TA treatment. Inhibited expression of genes involved in cell division cycle (cyclin D1, IGFBP-1, ras, E2F) was observed after exposure of DB rats to 300 mg TA/kg, explaining inhibited tissue repair in these rats. On the other hand, DB rats receiving 30 mg TA/kg exhibit delayed expression of genes involved in cell division cycle, explaining delayed tissue repair in these rats. In conclusion, impaired cyclin D1 signaling along with increased proteases and decreased protease inhibitors may explain impaired tissue repair that leads to progression of liver injury initiated by TA in DB rats.

  4. Speed and accuracy of visual image discrimination by rats.

    PubMed

    Reinagel, Pamela

    2013-01-01

    The trade-off between speed and accuracy of sensory discrimination has most often been studied using sensory stimuli that evolve over time, such as random dot motion discrimination tasks. We previously reported that when rats perform motion discrimination, correct trials have longer reaction times than errors, accuracy increases with reaction time, and reaction time increases with stimulus ambiguity. In such experiments, new sensory information is continually presented, which could partly explain interactions between reaction time and accuracy. The present study shows that a changing physical stimulus is not essential to those findings. Freely behaving rats were trained to discriminate between two static visual images in a self-paced, two-alternative forced-choice reaction time task. Each trial was initiated by the rat, and the two images were presented simultaneously and persisted until the rat responded, with no time limit. Reaction times were longer in correct trials than in error trials, and accuracy increased with reaction time, comparable to results previously reported for rats performing motion discrimination. In the motion task, coherence has been used to vary discrimination difficulty. Here morphs between the previously learned images were used to parametrically vary the image similarity. In randomly interleaved trials, rats took more time on average to respond in trials in which they had to discriminate more similar stimuli. For both the motion and image tasks, the dependence of reaction time on ambiguity is weak, as if rats prioritized speed over accuracy. Therefore we asked whether rats can change the priority of speed and accuracy adaptively in response to a change in reward contingencies. For two rats, the penalty delay was increased from 2 to 6 s. When the penalty was longer, reaction times increased, and accuracy improved. This demonstrates that rats can flexibly adjust their behavioral strategy in response to the cost of errors.

  5. The effects of exposure to electromagnetic field on rat myocardium.

    PubMed

    Kiray, Amac; Tayefi, Hamid; Kiray, Muge; Bagriyanik, Husnu Alper; Pekcetin, Cetin; Ergur, Bekir Ugur; Ozogul, Candan

    2013-06-01

    Exposure to electromagnetic fields (EMFs) causes increased adverse effects on biological systems. The aim of this study was to investigate the effects of EMF on heart tissue by biochemical and histomorphological evaluations in EMF-exposed adult rats. In this study, 28 male Wistar rats weighing 200-250 g were used. The rats were divided into two groups: sham group (n = 14) and EMF group (n = 14). Rats in sham group were exposed to same conditions as the EMF group except the exposure to EMF. Rats in EMF group were exposed to a 50-Hz EMF of 3 mT for 4 h/day and 7 days/week for 2 months. After 2 months of exposure, rats were killed; the hearts were excised and evaluated. Determination of oxidative stress parameters was performed spectrophotometrically. To detect apoptotic cells, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining and caspase-3 immunohistochemistry were performed. In EMF-exposed group, levels of lipid peroxidation significantly increased and activities of superoxide dismutase and glutathione peroxidase decreased compared with sham group. The number of TUNEL-positive cells and caspase-3 immunoreactivity increased in EMF-exposed rats compared with sham. Under electron microscopy, there were mitochondrial degeneration, reduction in myofibrils, dilated sarcoplasmic reticulum and perinuclear vacuolization in EMF-exposed rats. In conclusion, the results show that the exposure to EMF causes oxidative stress, apoptosis and morphologic damage in myocardium of adult rats. The results of our study indicate that EMF-related changes in rat myocardium could be the result of increased oxidative stress. Further studies are needed to demonstrate whether the exposure to EMF can induce adverse effects on myocardium.

  6. Lemon juice has protective activity in a rat urolithiasis model

    PubMed Central

    Touhami, Mohammed; Laroubi, Amine; Elhabazi, Khadija; Loubna, Farouk; Zrara, Ibtissam; Eljahiri, Younes; Oussama, Abdelkhalek; Grases, Félix; Chait, Abderrahman

    2007-01-01

    Background The use of herbal medicines (medicinal plants or phytotherapy) has recently gained popularity in Europe and the United States. Nevertheless the exact mechanism of the preventive effects of these products is still far to be clearly established, being its knowledge necessary to successfully apply these therapies to avoid stone formation. Methods The effect of oral lemon juice administration on calcium oxalate urolithiasis was studied in male Wistar rats. Rats were rendered nephrolithic by providing drinking water containing 0.75% ethylene glycol [v/v] (EG) and 2% ammonium chloride [w/v] (AC) for 10 days. In addition to EG/AC treatment, three groups of rats were also gavage-administered solutions containing 100%, 75% or 50% lemon juice [v/v] (6 μl solution/g body weight). Positive control rats were treated with EG/AC but not lemon juice. Negative control rats were provided with normal drinking water, and were administered normal water by gavage. Each group contained 6 rats. After 10 days, serum samples were collected for analysis, the left kidney was removed and assessed for calcium levels using flame spectroscopy, and the right kidney was sectioned for histopathological analysis using light microscopy. Results Analysis showed that the rats treated with EG/AC alone had higher amounts of calcium in the kidneys compared to negative control rats. This EG/AC-induced increase in kidney calcium levels was inhibited by the administration of lemon juice. Histology showed that rats treated with EG/AC alone had large deposits of calcium oxalate crystals in all parts of the kidney, and that such deposits were not present in rats also treated with either 100% or 75% lemon juice. Conclusion These data suggest that lemon juice has a protective activity against urolithiasis. PMID:17919315

  7. Exercise delays the hypoxic thermal response in rats.

    PubMed

    Ray, A D; Roberts, A J; Lee, S D; Farkas, G A; Michlin, C; Rifkin, D I; Ostrow, P T; Krasney, J A

    2003-07-01

    Exercise exacerbates acute mountain sickness. In infants and small mammals, hypoxia elicits a decrease in body temperature (Tb) [hypoxic thermal response (HTR)], which may protect against hypoxic tissue damage. We postulated that exercise would counteract the HTR and promote hypoxic tissue damage. Tb was measured by telemetry in rats (n = 28) exercising or sedentary in either normoxia or hypoxia (10% O2, 24 h) at 25 degrees C ambient temperature (Ta). After 24 h of normoxia, rats walked at 10 m/min on a treadmill (30 min exercise, 30 min rest) for 6 h followed by 18 h of rest in either hypoxia or normoxia. Exercising normoxic rats increased Tb ( degrees C) vs. baseline (39.68 +/- 0.99 vs. 38.90 +/- 0.95, mean +/- SD, P < 0.05) and vs. sedentary normoxic rats (38.0 +/- 0.09, P < 0.05). Sedentary hypoxic rats decreased Tb (36.15 +/- 0.97 vs. 38.0 +/- 0.36, P < 0.05) whereas Tb was maintained in the exercising hypoxic rats during the initial 6 h of exercise (37.61 +/- 0.55 vs. 37.72 +/- 1.25, not significant). After exercise, Tb in hypoxic rats reached a nadir similar to that in sedentary hypoxic rats (35.05 +/- 1.69 vs. 35.03 +/- 1.32, respectively). Tb reached its nadir significantly later in exercising hypoxic vs. sedentary hypoxic rats (10.51 +/- 1.61 vs. 5.36 +/- 1.83 h, respectively; P = 0.002). Significantly greater histopathological damage and water contents were observed in brain and lungs in the exercising hypoxic vs. sedentary hypoxic and normoxic rats. Thus exercise early in hypoxia delays but does not prevent the HTR. Counteracting the HTR early in hypoxia by exercise exacerbates brain and lung damage and edema in the absence of ischemia.

  8. Comparison of starvation and elastase models of emphysema in the rat

    SciTech Connect

    Harkema, J.R.; Mauderly, J.L.; Gregory, R.E.; Pickrell, J.A.

    1984-01-01

    Starvation and elastase-induced changes in rat lung structure, biochemistry, and function were compared as models of human pulmonary emphysema. Ten-week-old male rats were instilled intratracheally with either porcine pancreatic elastase in saline (E) or with saline alone. A group of the saline-instilled rats were fed one third of their normal food intake until a 45% loss of body weight occurred (S). The remaining saline-instilled rats served as control animals (C). Post-treatment evaluations included in vivo respiratory function, lung histopathologic and morphometric analyses, lung tissue proteinolytic activity, and lung collagen. The E rats had in vivo respiratory function changes more similar to human emphysema than those of S rats. All lung volume subdivisions were decreased in S rats and increased in E rats. The volume-pressure curve of S rats was shifted to the right of the C curve, whereas that of E rats was shifted to the left. Forced expiratory flow rates of E rats were decreased at all lung volumes, but those of S rats were not. Both E and S rats had larger terminal air spaces and less alveolar surface area than did C rats. The S rats had more collagen per gram lung and higher proteinolytic activity than did C or E rats. These results show that, although starvation induces some changes characteristic of human emphysema, elastase-treatment provides a model more similar to the human disease. 44 references, 5 figures, 4 tables.

  9. Anomalous extracellular diffusion in rat cerebellum.

    PubMed

    Xiao, Fanrong; Hrabe, Jan; Hrabetova, Sabina

    2015-05-01

    Extracellular space (ECS) is a major channel transporting biologically active molecules and drugs in the brain. Diffusion-mediated transport of these substances is hindered by the ECS structure but the microscopic basis of this hindrance is not fully understood. One hypothesis proposes that the hindrance originates in large part from the presence of dead-space (DS) microdomains that can transiently retain diffusing molecules. Because previous theoretical and modeling work reported an initial period of anomalous diffusion in similar environments, we expected that brain regions densely populated by DS microdomains would exhibit anomalous extracellular diffusion. Specifically, we targeted granular layers (GL) of rat and turtle cerebella that are populated with large and geometrically complex glomeruli. The integrative optical imaging (IOI) method was employed to evaluate diffusion of fluorophore-labeled dextran (MW 3000) in GL, and the IOI data analysis was adapted to quantify the anomalous diffusion exponent dw from the IOI records. Diffusion was significantly anomalous in rat GL, where dw reached 4.8. In the geometrically simpler turtle GL, dw was elevated but not robustly anomalous (dw = 2.6). The experimental work was complemented by numerical Monte Carlo simulations of anomalous ECS diffusion in several three-dimensional tissue models containing glomeruli-like structures. It demonstrated that both the duration of transiently anomalous diffusion and the anomalous exponent depend on the size of model glomeruli and the degree of their wrapping. In conclusion, we have found anomalous extracellular diffusion in the GL of rat cerebellum. This finding lends support to the DS microdomain hypothesis. Transiently anomalous diffusion also has a profound effect on the spatiotemporal distribution of molecules released into the ECS, especially at diffusion distances on the order of a few cell diameters, speeding up short-range diffusion-mediated signals in less permeable

  10. Manganese depresses rat heart muscle respiration.

    PubMed

    Miller, Kevin B; Caton, Joel S; Finley, John W

    2006-01-01

    It has previously been reported that moderately high dietary manganese (Mn) in combination with marginal magnesium (Mg) resulted in ultrastructural damage to heart mitochondria. Manganese may replace Mg in biological functions, including the role of enzyme cofactor. Manganese may accumulate and substitute for Mg during the condition of Mg-deficiency. The objective of the current study was to determine whether high Mn alters heart muscle respiration and Mg-enzyme activity as well as whole body Mn retention under marginal Mg. An additional objective was to determine whether high Mn results in increased oxidative stress. In experiment 1: forty-eight rats were fed a 2 x 3 factorial arrangement of Mn (10, 100, or 1000 mg/kg) and Mg (200 or 500 mg/kg). In experiment 2: thirty-two rats were fed one of four diets in a 2 x 2 factorial arrangement of Mn (10 or 250 mg/kg) and Mg (200 or 500 mg/kg). In experiment 3: thirty-two rats were fed one of four diets in a 2 x 2 factorial arrangement of Mn (10 or 650 mg/kg) and Mg (200 or 500 mg/kg). In experiment 2, high Mn and marginal Mg reduced (P<0.05) oxygen consumption of left ventricle muscle. Marginal Mg, but not Mn, reduced (P<0.05) activity of sarcoplasmic reticulum calcium-ATPase enzyme. Dietary Mg had no affect on (54)Mn kinetics, but high dietary Mn decreased (P<0.01) absorption, retention, and rate of excretion of (54)Mn. Neither cellular stress, measured by Comet assay, nor antioxidant activities were increased by high Mn. A strong interaction (P<0.001) between increasing Mn and adequate Mg on hematology was observed. These results confirm previous research in swine that high Mn alters myocardial integrity as well as function, but not as a result of altered calcium transport or oxidative stress.

  11. Characterization of the rat developmental liver transcriptome.

    PubMed

    Chapple, Richard H; Tizioto, Polyana C; Wells, Kevin D; Givan, Scott A; Kim, JaeWoo; McKay, Stephanie D; Schnabel, Robert D; Taylor, Jeremy F

    2013-04-16

    Gene regulation and transcriptome studies have been enabled by the development of RNA-Seq applications for high-throughput sequencing platforms. Next generation sequencing is remarkably efficient and avoids many issues inherent in hybridization-based microarray methodologies including the exon-specific dependence of probe design. Biologically relevant transcripts including messenger and regulatory RNAs may now be quantified and annotated regardless of whether they have previously been observed. We used RNA-Seq to investigate global patterns of gene expression in early developing rat liver. Liver samples from timed-pregnant Lewis rats were collected at six fetal and neonatal stages [embryonic day (E)14, E16, E18, E20, postnatal day (P)1, P7], transcripts were sequenced using an Illumina HiSeq 2000, and data analysis was performed with the Tuxedo software suite. Genes and isoforms differing in abundance were queried for enrichment within functionally related gene groups using the Functional Annotation Tool of the DAVID Bioinformatics Database. While hematopoietic gene expression is initiated by E14, hepatocyte maturation is a gradual process involving clusters of genes responsible for response to nutrients and enzymes responsible for glycolysis and fatty acid catabolism. Following birth, a large cluster of differentially abundant genes was enriched for mitochondrial gene expression and cholesterol synthesis indicating that by 1 wk of age, the liver is engaged in lipid sensing and bile production. Clustering results for differentially abundant genes and isoforms were similar with the greatest difference for the E14/E16 comparison. Finally, a bioinformatic approach was used to annotate 1,307 novel liver transcripts assembled from sequences that aligned to intergenic regions of the rat genome.

  12. Cold storage of rat hepatocyte spheroids.

    PubMed

    Liu, Hongling; Yu, Yue; Glorioso, Jaime; Mao, Shennen; Rodysil, Brian; Amiot, Bruce P; Rinaldo, Piero; Nyberg, Scott L

    2014-01-01

    Cell-based therapies for liver disease rely on a high-quality supply of hepatocytes and a means for storage during transportation from site of isolation to site of usage. Unfortunately, frozen cryopreservation is associated with unacceptable loss of hepatocyte viability after thawing. The purpose of this study was to optimize conditions for cold storage of rat hepatocyte spheroids without freezing. Rat hepatocytes were isolated by a two-step perfusion method; hepatocyte spheroids were formed during 48 h of rocked culture in serum-free medium (SFM). Spheroids were then maintained in rocked culture at 37 °C (control condition) or cold stored at 4 °C for 24 or 48 h in six different cold storage solutions: SFM alone; SFM + 1 mM deferoxamine (Def); SFM + 1 μM cyclosporin A (CsA); SFM + 1 mM Def + 1 μM CsA, University of Wisconsin (UW) solution alone, UW + 1 mM Def. Performance metrics after cold storage included viability, gene expression, albumin production, and functional activity of cytochrome P450 enzymes and urea cycle proteins. We observed that cold-induced injury was reduced significantly by the addition of the iron chelator (Def) to both SFM and UW solution. Performance metrics (ammonia detoxification, albumin production) of rat hepatocyte spheroids stored in SFM + Def for 24 h were significantly increased from SFM alone and approached those in control conditions, while performance metrics after cold storage in SFM alone or cold storage for 48 h were both significantly reduced. A serum-free medium supplemented with Def allowed hepatocyte spheroids to tolerate 24 h of cold storage with less than 10% loss in viability and functionality. Further research is warranted to optimize a solution for extended cold storage of hepatocyte spheroids.

  13. Goiter formation following prostaglandin administration in rats.

    PubMed Central

    Lupulescu, A.

    1976-01-01

    Prostaglandins (PGE1 and PGE2) induced a hyperplastic microfollicular goiter with a high radioiodine (131I) thyroid uptake, increased endocytosis, a heavy autoradiographic (125I) reaction, and a moderate increase of thyroid hormones (T4, T3), thyroxine-binding globulin (TGB), and thyrotropin (TSH) concentrations in adult rats. Ultrastructurally, both prostaglandins (E1 and E2) markedly stimulated the thyroid cell activity and increased the number of pseudopodia, the size of colloid and dense granule populations, and the number of polysomes. Conversely, a hypofunction of thyroid glands with low radioiodine (131I) thyroid uptake, a decreased autoradiographic (125I) reaction, and a moderate decrease in T4, T3, TGB, and TSH concentrations were observed following prostaglandin F 2alpha. Ultrastructurally, a decrease in size of the colloid and dense granule population and the number of degenerative mitochondria occurred infollicular cells. An intense hyperplasia of parafollicular (C) cells, with abundant population of characteristic dense granules, could be seen in PGF 2alpha-treated rats. A marked decrease of radioiodine (131I) uptake, endocytosis, and autoradiographic (125I) reaction and a sharp decline in T4, T3, and TBG were observed in hypophysectomized and chronically prostaglandin-treated rats. Light and electron microscopy revealed signs of an advanced thyroid hypofunction with flat cuboidal cells, reduced microvilli, scarce endoplasmic reticulum, and few dense droplets. The present findings demonstrate that the chronic administration of prostaglandins exerts significant effects of thyroid gland and goiter formation (goitrogenesis), radioiodine metabolism, and hormone synthesis, and that these effects are mediated by TSH secretion. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 PMID:970439

  14. Anomalous Extracellular Diffusion in Rat Cerebellum

    PubMed Central

    Xiao, Fanrong; Hrabe, Jan; Hrabetova, Sabina

    2015-01-01

    Extracellular space (ECS) is a major channel transporting biologically active molecules and drugs in the brain. Diffusion-mediated transport of these substances is hindered by the ECS structure but the microscopic basis of this hindrance is not fully understood. One hypothesis proposes that the hindrance originates in large part from the presence of dead-space (DS) microdomains that can transiently retain diffusing molecules. Because previous theoretical and modeling work reported an initial period of anomalous diffusion in similar environments, we expected that brain regions densely populated by DS microdomains would exhibit anomalous extracellular diffusion. Specifically, we targeted granular layers (GL) of rat and turtle cerebella that are populated with large and geometrically complex glomeruli. The integrative optical imaging (IOI) method was employed to evaluate diffusion of fluorophore-labeled dextran (MW 3000) in GL, and the IOI data analysis was adapted to quantify the anomalous diffusion exponent dw from the IOI records. Diffusion was significantly anomalous in rat GL, where dw reached 4.8. In the geometrically simpler turtle GL, dw was elevated but not robustly anomalous (dw = 2.6). The experimental work was complemented by numerical Monte Carlo simulations of anomalous ECS diffusion in several three-dimensional tissue models containing glomeruli-like structures. It demonstrated that both the duration of transiently anomalous diffusion and the anomalous exponent depend on the size of model glomeruli and the degree of their wrapping. In conclusion, we have found anomalous extracellular diffusion in the GL of rat cerebellum. This finding lends support to the DS microdomain hypothesis. Transiently anomalous diffusion also has a profound effect on the spatiotemporal distribution of molecules released into the ECS, especially at diffusion distances on the order of a few cell diameters, speeding up short-range diffusion-mediated signals in less permeable

  15. Characterization of muscarinic receptors in rat kidney.

    PubMed

    Blankesteijn, W M; Siero, H L; Rodrigues de Miranda, J F; van Megen, Y J; Russel, F G

    1993-01-01

    Muscarinic receptors in mammalian kidney seem to be involved in diuresis. In this study we give a detailed characterization of receptors in rat kidney. Specific binding of [3H](-)-quinuclidinylbenzilate ([3H]QNB) to membranes of rat kidney cortex was saturable and of high affinity. A dissociation constant of 0.063 +/- 0.003 nM and a receptor density of 1.46 +/- 0.07 pmol/g wet weight were obtained. The dissociation kinetics could be best described by assuming a mono-exponential function (k-1 = (0.52 +/- 0.1) x 10(-4) s-1). The binding of [3H]QNB reached a maximum in 60 min at 0.6 nM at 37 degrees C. Competition experiments with the enantiomers of benzetimide confirmed the muscarinic nature of the [3H]QNB binding sites. The inhibition constants of pirenzepine (0.23 +/- 0.02 microM), (+-)-hexahydrosiladifenidol (0.040 +/- 0.002 microM), AF-DX 116 (1.45 +/- 0.07 microM), methoctramine (1.67 +/- 0.02 microM) and gallamine (78 +/- 3 microM) classified this receptor as an M3 receptor. Inhibition of [3H]QNB binding by the agonists methylfurtrethonium, arecoline, isoarecoline methiodide, arecaidine propargyl ester and McN-A-343 displayed monophasic inhibition curves. With (+/-)-cis-2-methyl-4-dimethylaminomethyl-1,3- dioxolane methiodide in two out of four experiments a small (11%) population of high affinity agonist sites could be detected. The potassium sparing diuretic amiloride inhibited [3H]QNB binding (36 +/- 3 microM). Although in a way related to the amiloride binding site, the muscarinic receptors in rat kidney are unlikely to be the primary target of diuretic action of this drug. PMID:8420789

  16. Clopidogrel delays gastric ulcer healing in rats.

    PubMed

    Luo, Jiing-Chyuan; Huo, Teh-Ia; Hou, Ming-Chih; Lin, Hsiao-Yi; Li, Chung-Pin; Lin, Han-Chieh; Chang, Full-Young; Lee, Fa-Yauh

    2012-11-15

    Clopidogrel is not safe enough for the gastric mucosa in patients with high risk of peptic ulcer. This study aimed to explore if clopidogrel delays gastric ulcer healing and elucidate the involved mechanisms. Gastric ulcer was induced in rats and the ulcer size, mucosal epithelial cell proliferation of the ulcer margin, expression of growth factors [epidermal growth factor (EGF), basic fibroblast growth factor] and their receptors, and signal transduction pathways for cell proliferation were measured and compared between the clopidogrel-treated group and untreated controls. For the in vitro part, rat gastric mucosal epithelial cell line (RGM-1 cells) was used to establish EGF receptor over-expressed cells. Cell proliferation and molecular change under EGF treatment (10ng/ml) with and without clopidogrel (10(-6)M) were demonstrated. Ulcer size was significantly larger in the clopidogrel-treated group compared to the control and mucosal epithelial cell proliferation of the ulcer margin was significantly decreased in the clopidogrel-treated group (P<0.05). Clopidogrel (2mg and 10mg/kg/day) significantly decreased ulcer-induced gastric epithelial cell proliferation and ulcer-stimulated expressions of EGF receptor and phosphorylated extracellular signal-regulated kinase (PERK) at the ulcer margin (P<0.05). Clopidogrel (10(-6)M) also inhibited EGF-stimulated EGF receptor, PERK expression, and cell proliferation in RGM-1 cells (P<0.05), and caused much less inhibition of EGF-stimulated cell proliferation in EGF receptor over-expressed RGM-1 cells than in RGM-1 cells (22% vs. 32% reduction). In conclusion, clopidogrel delays gastric ulcer healing in rats via inhibiting gastric epithelial cell proliferation, at least by inhibition of the EGF receptor-ERK signal transduction pathway.

  17. Bis-(5'-guanosyl) tetraphosphatase in rat tissues.

    PubMed Central

    Cameselle, J C; Costas, M J; Sillero, M A; Sillero, A

    1982-01-01

    The occurrence and distribution of bis-(5'-guanosyl) tetraphosphatase activity towards dinucleoside tetraphosphates between the 27 000 g supernatant and sedimented fraction were studied in liver, kidney, brain, muscle and intestinal mucosa from rat. The p1p4-bis-(5'-guanosyl) tetraphosphate-hydrolysing activities found in total homogenates were 0.77, 1.44, 0.39, 0.36 and 2.14 units (mumol/min)/g respectively. The activities found in the 27000 g-sedimented fractions were 74, 49, 11, 4 and 96% of those present in the homogenates respectively. The properties of the soluble enzymes were investigated. All of them have low Km values for p1p4-bis-(5'-guanosyl) tetraphosphate (from 2 to 50 microM), are competitively inhibited by guanosine 5'-tetraphosphate with K1 values from 10 to 160 nM, have molecular weights of about 21 000, require Mg2+ or Mn2+ and are inhibited by Ca2+. These properties show that bis-(5'-guanosyl) tetraphosphatase (EC 3.6.1.17), an enzyme previously characterized in Artemia salina and rat liver [Warner & Finamore (1965) Biochemistry 4, 1568-1575; Vallejo, Sillero & Sillero (1974) Biochim, Biophys. Acta 358, 117-125; Lobatón, Vallejo, Sillero & Sillero (1975) Eur. J. Biochem. 50, 495-501], is present in all the rat tissues examined. The inhibition of the enzyme by Ca2+ could be related to the effect of p1p4-bis-(5'-adenosyl) tetraphosphate as a trigger of DNA synthesis [Grummt, Waltl, Jantzen, Hamprecht, Huebscher & Kuenzle (1979) Proc. Natl. Acad. Sci. U.S.A. 76, 6081-6085]. PMID:6282267

  18. Anomalous extracellular diffusion in rat cerebellum.

    PubMed

    Xiao, Fanrong; Hrabe, Jan; Hrabetova, Sabina

    2015-05-01

    Extracellular space (ECS) is a major channel transporting biologically active molecules and drugs in the brain. Diffusion-mediated transport of these substances is hindered by the ECS structure but the microscopic basis of this hindrance is not fully understood. One hypothesis proposes that the hindrance originates in large part from the presence of dead-space (DS) microdomains that can transiently retain diffusing molecules. Because previous theoretical and modeling work reported an initial period of anomalous diffusion in similar environments, we expected that brain regions densely populated by DS microdomains would exhibit anomalous extracellular diffusion. Specifically, we targeted granular layers (GL) of rat and turtle cerebella that are populated with large and geometrically complex glomeruli. The integrative optical imaging (IOI) method was employed to evaluate diffusion of fluorophore-labeled dextran (MW 3000) in GL, and the IOI data analysis was adapted to quantify the anomalous diffusion exponent dw from the IOI records. Diffusion was significantly anomalous in rat GL, where dw reached 4.8. In the geometrically simpler turtle GL, dw was elevated but not robustly anomalous (dw = 2.6). The experimental work was complemented by numerical Monte Carlo simulations of anomalous ECS diffusion in several three-dimensional tissue models containing glomeruli-like structures. It demonstrated that both the duration of transiently anomalous diffusion and the anomalous exponent depend on the size of model glomeruli and the degree of their wrapping. In conclusion, we have found anomalous extracellular diffusion in the GL of rat cerebellum. This finding lends support to the DS microdomain hypothesis. Transiently anomalous diffusion also has a profound effect on the spatiotemporal distribution of molecules released into the ECS, especially at diffusion distances on the order of a few cell diameters, speeding up short-range diffusion-mediated signals in less permeable

  19. The pituitary - Aging and spaceflown rats

    NASA Technical Reports Server (NTRS)

    Hymer, W. C.; Grindeland, R. E.

    1991-01-01

    Decrements in growth hormone (GH) release we observed in two spaceflight experiments and four tail-suspended rat studies mimic age-associated changes in the mammalian pituitary GH system seen by Meites and others. The spaceflight data suggest that formation of high molecular weight bioactive disulfide-linked aggregates of the 20 and 22K monomeric GH forms may be reduced in microgravity, thereby, reducing target tissue activity. Correlative studies to confirm spaceflight as a model for pituitary GH system aging should include: (1) investigation of mechanisms of intracellular hormone packaging, (2) consequences to biological activity of the hormone molecule, and (3) study of intracellular microtubule dynamics.

  20. Morphine reduces social cohesion in rats.

    PubMed

    Panksepp, J; Najam, N; Soares, F

    1979-08-01

    The effect of low (1 mg/kg) doses of morphine on maintenance of physical proximity were evaluated in paired rats observed in a 4 square foot test arena. Morphine reliably reduced proximity maintenance time, and this was apparently not due to sedation, since the effect was unmodified by doses of amphetamine which substantially increased motor activity. The effects of naloxone were inconsistent on this measure of social motivation. In general, the results are consistent with the theoretical proposition that a brain neurochemical change which might lead to social attraction is the activation of endogenous opioid systems. When opiate activity is exogenously sustained, animals exhibit a subnormal tendency to be gregarious.

  1. Native structure of rat liver immune proteasomes.

    PubMed

    Stepanova, A A; Lyupina, Yu V; Sharova, N P; Erokhov, P A

    2016-05-01

    Native structure of active forms of rat liver immune proteasomes has been studied by two-dimensional electrophoresis method modified for analysis of unpurified protein fractions. The developed method allowed revealing the proteasome immune subunits LMP7 and LMP2 in 20S subparticles and in the structures bound to one or two PA28αβ activators, but not to the PA700 activator, which is involved in the hydrolysis of ubiquitinated proteins. The results obtained indicate the participation of the immune proteasomes in delicate regulatory mechanisms based on the production of biologically active peptides and exclude their participation in processes of crude degradation of "rotated" ubiquitinated proteins. PMID:27417720

  2. CHARACTERIZATION OF RAT LIVER SUBCELLULAR MEMBRANES

    PubMed Central

    DeHeer, David H.; Olson, Merle S.; Pinckard, R. Neal

    1974-01-01

    The induction of acute hepatocellular necrosis in rats resulted in the production of complement fixing, IgM autoantibodies directed toward inner and outer mitochondrial membranes, microsomal membrane, lysosomal membrane, nuclear membrane, cytosol, but not to plasma membrane. Utilizing selective absorption procedures it was demonstrated that each subcellular membrane fraction possessed unique autoantigenic activity with little or no cross-reactivity between the various membrane fractions. It is proposed that the development of membrane-specific autoantibodies may provide an immunological marker useful in the differential characterization of various subcellular membranes. PMID:4813214

  3. Plantar decubitus ulcers in rats and rabbits.

    PubMed

    Honma, M; Kast, A

    1989-07-01

    A high incidence of plantar decubitus ulcers, 35% in males and 22 or 45% in females, respectively, occurred in rats of two carcinogenicity studies independent of the bedding used, hard or soft wood chips. Among rabbits kept in chrome-plated wire cages, about 2-year-old female breeders suffered from the plantar ulcers, but not their male partners of the same age group. The causes of the foot disease appear to be manifold, however, in our cases the lesions could be prevented in both species by housing on a cage floor made from flattened stainless wire.

  4. Corona discharge influences ozone concentrations near rats.

    PubMed

    Goheen, Steven C; Gaither, Kari; Anantatmula, Shantha M; Mong, Gary M; Sasser, Lyle B; Lessor, Delbert

    2004-02-01

    Ozone can be produced by corona discharge either in dry air or when one electrode is submerged in water. Since ozone is toxic, we examined whether ozone production by corona near laboratory animals could reach levels of concern. Male rats were exposed to a corona discharge and the concentration of ozone produced was measured. The resulting concentration of ozone ranged from ambient levels to 250 ppb when animals were located 1 cm from a 10 kV source. Similar ozone concentrations were observed when a grounded water source was present. Possible explanations for, as well as concerns regarding, ozone production under these conditions are discussed. PMID:14735560

  5. Cholinergic muscarinic receptors in rat cochlea.

    PubMed

    van Megen, Y J; Klaassen, A B; Rodrigues de Miranda, J F; Kuijpers, W

    1988-11-22

    Specific 3H-1-quinuclidinylbenzilate (3H-1-QNB) binding to rat cochlea homogenates occurs to a homogeneous class of binding sites with Kd = 0.13 +/- 0.01 nM and Bmax = 0.57 +/- 0.07 fmol per cochlea. Binding is stereoselectively inhibited by benzetimide enantiomers. Dexetimide was more effective than levetimide in displacing 3H-1-QNB from its binding sites (Ki = 4 x 10(-10) M and 6.5 x 10(-6) M, respectively). Pirenzepine inhibits 3H-1-QNB binding with low affinity (Ki = 2 x 10(-6) M), classifying the binding sites as muscarinic M2 receptors. PMID:3214711

  6. Formaldehyde-induced shrinkage of rat thymocytes.

    PubMed

    Nakao, Hiromi; Umebayashi, Chisato; Nakata, Mami; Nishizaki, Yasutaka; Noda, Katuhiko; Okano, Yoshiro; Oyama, Yasuo

    2003-01-01

    To test the possibility that micromolar formaldehyde, a metabolite of methanol derived from aspartame, exerts cytotoxicity, its effect on rat thymocytes was examined under the in vitro condition using a flow cytometer. Incubation of thymocytes with formaldehyde at 100 micro M or more for 24 h significantly increased the populations of shrunken cells and cells with hypodiploid DNA. The peak blood concentration of methanol in human subjects administered abuse doses of aspartame has been reported to exceed 2 mg/dL (625 micro M). It would increase the population of thymocytes undergoing apoptosis if formaldehyde at 100 micro M or more appears in the blood after administration of aspartame.

  7. Pulmonary toxicity of beryllium in albino rat

    SciTech Connect

    Goel, K.A.; Agrawal, V.P.; Garg, V.

    1980-01-01

    Arsenic compounds, if chronically exposed to human beings, significantly increase incidences of epidermoid carcinomas of the skin and lung. Nickel has been considered to be an important metallic carcinogen. Regarding beryllium, different opinions are held so far as its carcinogenic nature is concerned. While it is reported that there is an equivocal increase in the incidences of respiratory cancers in patients with chronic pulmonary berylliosis, investigation shows no increase in the incidence of respiratory cancer. Among experimental animals, intravenous injections of suspensions of beryllium salts to rabbits have been shown to induce osteogenic sarcomas. This abstract deals with the histopathological and enzymological study of lungs of albino rats after prolonged beryllium treatment.

  8. Impact of streptozotocin on altering normal glucose homeostasis during insulin testing in diabetic rats compared to normoglycemic rats

    PubMed Central

    Qinna, Nidal A; Badwan, Adnan A

    2015-01-01

    Streptozotocin (STZ) is currently the most used diabetogenic agent in testing insulin and new antidiabetic drugs in animals. Due to the toxic and disruptive nature of STZ on organs, apart from pancreas, involved in preserving the body’s normal glucose homeostasis, this study aims to reassess the action of STZ in inducing different glucose response states in diabetic rats while testing insulin. Diabetic Sprague-Dawley rats induced with STZ were classified according to their initial blood glucose levels into stages. The effect of randomizing rats in such a manner was investigated for the severity of interrupting normal liver, pancreas, and kidney functions. Pharmacokinetic and pharmacodynamic actions of subcutaneously injected insulin in diabetic and nondiabetic rats were compared. Interruption of glucose homeostasis by STZ was challenged by single and repeated administrations of injected insulin and oral glucose to diabetic rats. In diabetic rats with high glucose (451–750 mg/dL), noticeable changes were seen in the liver and kidney functions compared to rats with lower basal glucose levels. Increased serum levels of recombinant human insulin were clearly indicated by a significant increase in the calculated maximum serum concentration and area under the concentration–time curve. Reversion of serum glucose levels to normal levels pre- and postinsulin and oral glucose administrations to STZ diabetic rats were found to be variable. In conclusion, diabetic animals were more responsive to insulin than nondiabetic animals. STZ was capable of inducing different levels of normal glucose homeostasis disruption in rats. Both pharmacokinetic and pharmacodynamic actions of insulin were altered when different initial blood glucose levels of STZ diabetic rats were selected for testing. Such findings emphasize the importance of selecting predefined and unified glucose levels when using STZ as a diabetogenic agent in experimental protocols evaluating new antidiabetic agents

  9. Generation of a New Model Rat: Nrf2 Knockout Rats Are Sensitive to Aflatoxin B1 Toxicity.

    PubMed

    Taguchi, Keiko; Takaku, Misaki; Egner, Patricia A; Morita, Masanobu; Kaneko, Takehito; Mashimo, Tomoji; Kensler, Thomas W; Yamamoto, Masayuki

    2016-07-01

    THE TRANSCRIPTION FACTOR NRF2: (NF-E2-related-factor 2) REGULATES A BATTERY OF ANTIOXIDATIVE STRESS-RESPONSE GENES AND DETOXICATION GENES, AND NRF2 KNOCKOUT LINES OF MICE HAVE BEEN CONTRIBUTING CRITICALLY TO THE CLARIFICATION OF ROLES THAT NRF2 PLAYS FOR CELL PROTECTION HOWEVER, THERE ARE APPARENT LIMITATIONS IN USE OF THE MOUSE MODELS FOR INSTANCE, RATS EXHIBIT MORE SUITABLE FEATURES FOR TOXICOLOGICAL OR PHYSIOLOGICAL EXAMINATIONS THAN MICE IN THIS STUDY, WE GENERATED 2 LINES OF NRF2 KNOCKOUT RATS BY USING A GENOME EDITING TECHNOLOGY; 1 LINE HARBORS A 7-BP DELETION Δ7 AND THE OTHER LINE HARBORS A 1-BP INSERTION +1 IN THE NRF2 GENE IN THE LIVERS OF RATS HOMOZYGOUSLY DELETING THE NRF2 GENE, AN ACTIVATOR OF NRF2 SIGNALING, CDDO-IM, COULD NOT INDUCE EXPRESSION OF REPRESENTATIVE NRF2 TARGET GENES TO EXAMINE ALTERED TOXICOLOGICAL RESPONSE, WE TREATED THE NRF2 KNOCKOUT RATS WITH AFLATOXIN B1 AFB1, A CARCINOGENIC MYCOTOXIN THAT ELICITS GENE MUTATIONS THROUGH BINDING OF ITS METABOLITES TO DNA AND FOR WHICH THE RAT HAS BEEN PROPOSED AS A REASONABLE SURROGATE FOR HUMAN TOXICITY INDEED, IN THE NRF2 KNOCKOUT RAT LIVERS THE ENZYMES OF THE AFB1 DETOXICATION PATHWAY WERE SIGNIFICANTLY DOWNREGULATED SINGLE DOSE ADMINISTRATION OF AFB1 INCREASED HEPATOTOXICITY AND BINDING OF AFB1-N7-GUANINE TO HEPATIC DNA IN NRF2 KNOCKOUT RATS COMPARED WITH WILD-TYPE NRF2 KNOCKOUT RATS REPEATEDLY TREATED WITH AFB1 WERE PRONE TO LETHALITY AND CDDO-IM WAS NO LONGER PROTECTIVE THESE RESULTS DEMONSTRATE THAT NRF2 KNOCKOUT RATS ARE QUITE SENSITIVE TO AFB1 TOXICITIES AND THIS RAT GENOTYPE EMERGES AS A NEW MODEL ANIMAL IN TOXICOLOGY.

  10. The Effects of Spaceflight on the Rat Circadian Timing System

    NASA Technical Reports Server (NTRS)

    Fuller, Charles A.; Murakami, Dean M.; Hoban-Higgins, Tana M.; Fuller, Patrick M.; Robinson, Edward L.; Tang, I.-Hsiung

    2003-01-01

    Two fundamental environmental influences that have shaped the evolution of life on Earth are gravity and the cyclic changes occurring over the 24-hour day. Light levels, temperature, and humidity fluctuate over the course of a day, and organisms have adapted to cope with these variations. The primary adaptation has been the evolution of a biological timing system. Previous studies have suggested that this system, named the circadian (circa - about; dies - a day) timing system (CTS), may be sensitive to changes in gravity. The NASA Neurolab spaceflight provided a unique opportunity to evaluate the effects of microgravity on the mammalian CTS. Our experiment tested the hypotheses that microgravity would affect the period, phasing, and light sensitivity of the CTS. Twenty-four Fisher 344 rats were exposed to 16 days of microgravity on the Neurolab STS-90 mission, and 24 Fisher 344 rats were also studied on Earth as one-G controls. Rats were equipped with biotelemetry transmitters to record body temperature (T(sub b)) and heart rate (HR) continuously while the rats moved freely. In each group, 18 rats were exposed to a 24-hour light-dark (LD 12:12) cycle, and six rats were exposed to constant dim red-light (LL). The ability of light to induce a neuronal activity marker (c-fos) in the circadian pacemaker of the brain, the suprachiasmatic nucleus (SCN), was examined in rats studied on flight days two (FD2) and 14 (FD14), and postflight days two (R+1) and 14 (R+13). The flight rats in LD remained synchronized with the LD cycle. However, their T(sub b), rhythm was markedly phase-delayed relative to the LD cycle. The LD flight rats also had a decreased T(sub b) and a change in the waveform of the T(sub b) rhythm compared to controls. Rats in LL exhibited free-running rhythms of T(sub b), and HR; however, the periods were longer in microgravity. Circadian period returned to preflight values after landing. The internal phase angle between rhythms was different in flight than

  11. Intermittent hypoxia maintains glycemia in streptozotocin-induced diabetic rats.

    PubMed

    Chen, Xiaofei; Zhao, Tong; Huang, Xin; Wu, Liying; Wu, Kuiwu; Fan, Ming; Zhu, Lingling

    2016-05-01

    Increasing studies have shown protective effects of intermittent hypoxia on brain injury and heart ischemia. However, the effect of intermittent hypoxia on blood glucose metabolism, especially in diabetic conditions, is rarely observed. The aim of this study was to investigate whether intermittent hypoxia influences blood glucose metabolism in type 1 diabetic rats. Streptozotocin-induced diabetic adult rats and age-matched control rats were treated with intermittent hypoxia (at an altitude of 3 km, 4 h per day for 3 weeks) or normoxia as control. Fasting blood glucose, body weight, plasma fructosamine, plasma insulin, homeostasis model assessment of insulin resistance (HOMA-IR), pancreas β-cell mass, and hepatic and soleus glycogen were measured. Compared with diabetic rats before treatment, the level of fasting blood glucose in diabetic rats after normoxic treatment was increased (19.88 ± 5.69 mmol/L vs. 14.79 ± 5.84 mmol/L, p < 0.05), while it was not different in diabetic rats after hypoxic treatment (13.14 ± 5.77 mmol/L vs. 14.79 ± 5.84 mmol/L, p > 0.05). Meanwhile, fasting blood glucose in diabetic rats after hypoxic treatment was also lower than that in diabetic rats after normoxic treatment (13.14 ± 5.77 mmol/L vs. 19.88 ± 5.69 mmol/L, p<0.05). Plasma fructosamine in diabetic rats receiving intermittent hypoxia was significantly lower than that in diabetic rats receiving normoxia (1.28 ± 0.11 vs. 1.39 ± 0.11, p < 0.05), while there were no significant changes in body weight, plasma insulin and β-cell mass. HOMA-IR in diabetic rats after hypoxic treatment was also lower compared with diabetic rats after normoxic treatment (3.48 ± 0.48 vs. 3.86 ± 0.42, p < 0.05). Moreover, intermittent hypoxia showed effect on the increase of soleus glycogen but not hepatic glycogen. We conclude that intermittent hypoxia maintains glycemia in streptozotocin-induced diabetic rats and its regulation on muscular

  12. Analysis of metabolites in plasma reveals distinct metabolic features between Dahl salt-sensitive rats and consomic SS.13(BN) rats.

    PubMed

    Wang, Le; Hou, Entai; Wang, Zhengjun; Sun, Na; He, Liqing; Chen, Lan; Liang, Mingyu; Tian, Zhongmin

    2014-07-18

    Salt-sensitive hypertension is a major risk factor for cardiovascular disorders. Our previous proteomic study revealed substantial differences in several proteins between Dahl salt-sensitive (SS) rats and salt-insensitive consomic SS.13(BN) rats. Subsequent experiments indicated a role of fumarase insufficiency in the development of hypertension in SS rats. In the present study, a global metabolic profiling study was performed using gas chromatography/mass spectrometry (GC/MS) in plasma of SS rats (n=9) and SS.13(BN) rats (n=8) on 0.4% NaCl diet, designed to gain further insights into the relationship between alterations in cellular intermediary metabolism and predisposition to hypertension. Principal component analysis of the data sets revealed a clear clustering and separation of metabolic profiles between SS rats and SS.13(BN) rats. 23 differential metabolites were identified (P<0.05). Higher levels of five TCA cycle metabolites, fumarate, cis-aconitate, isocitrate, citrate and succinate, were observed in SS rats. Pyruvate, which connects TCA cycle and glycolysis, was also increased in SS rats. Moreover, lower activity levels of fumarase, aconitase, α-ketoglutarate dehydrogenase and succinyl-CoA synthetase were detected in the heart, liver or skeletal muscles of SS rats. The distinct metabolic features in SS and SS.13(BN) rats indicate abnormalities of TCA cycle in SS rats, which may play a role in predisposing SS rats to developing salt-sensitive hypertension.

  13. Population dynamics of small mammals in semi-arid regions: a comparative study of demographic variability in two rodent species.

    PubMed Central

    Lima, Mauricio; Stenseth, Nils Chr; Leirs, Herwig; Jaksic, Fabián M

    2003-01-01

    The seasonally determined demographic structure of two semi-arid rodents, both agricultural pest species (the leaf-eared mouse (Phyllotis darwini) in Chile and the multimammate mouse (Mastomys natalensis) in Tanzania), is analysed using capture-mark-recapture (CMR) statistical models and measures for elasticity (the relative change in the growth rate due to a relative unit change in the parameter of concern) derived from projection linear matrix models. We demonstrate that reproduction and survival during the breeding season contribute approximately equally to population growth in the leaf-eared mouse, whereas the multimammate mouse is characterized by a more clearly defined seasonal structure into breeding and non-breeding seasons and that reproduction contributes far more than survival during the breeding season. On this basis, we discuss evolutionary and applied (pest control) issues. Regarding the evolution of life histories (leading to a maximization of the overall net annual growth rate), we suggest that for the leaf-eared mouse, features favouring survival throughout the year will provide selective value, but that during the main breeding season, features favouring reproduction and survival are about equally favourable. For the multimammate mouse, features favouring survival are particularly important outside the breeding season, whereas during the breeding season features favouring reproduction are more important. Regarding pest control (aiming at reducing the overall net annual growth rate), we suggest that (ignoring economic considerations) affecting survival outside the main breeding season is particularly effective for the leaf-eared mouse, a feature that is even more the case for the multimammate mouse. In sum, we demonstrate through this comparative study that much is to be learnt from studying the dynamics of fluctuating small rodents-a focal issue within much of population ecology. PMID:14561287

  14. Anthropogenic soils and land use patterns in relation to small mammal and flea abundance in plague endemic area of Western Usambara Mountains, Tanzania.

    PubMed

    Kimaro, Didas N; Msanya, Balthazar M; Meliyo, Joel; Hieronimo, Proches; Mwango, Sibaway; Kihupi, Nganga I; Gulinck, Hubert; Deckers, Jozef A

    2014-07-01

    Heterogeneity in the landscapes of West Usambara Mountains on land use and human activities has been reported. However, the interface of land use patterns and human modified soils with small mammal and flea abundance for possible explanation of plague has not been explored. This study was carried out to determine the link between anthropogenic soils and land use patterns on small mammal and flea abundance and the occurrence of reported plague in the Western Usambara Mountains in Tanzania. Standard soil survey methods were used to identify and describe soils and land use patterns on lower slopes and valley bottoms on which the surrounding villages are reported to have high and medium plague frequencies. The identified soils were characterised in terms of their morphological and physico-chemical properties and classified according to FAO-World Reference Base for Soil Resources. Small mammals were trapped on the same landscape positions and identified to genus/species level. Fleas were removed from the trapped small mammals, counted and identified to species level. In total 57 small mammals were captured from which 32 fleas were collected. Results show that human settlements and mixed cultivation on lower slopes and continuous vegetable cropping in the valley bottoms are dominant land use types. Intensive use of forest soils, manuring and irrigation on farms in the studied landscapes have contributed to the development of uniquely human modified soils namely Hortic Anthrosols in the lower slopes and Plaggic Irragric Hortic Anthrosols in valley bottoms. The identified anthropogenic soils and land use patterns are associated with high abundance of small mammals (Mastomys natalensis) and flea species (Xenopsylla brasiliensis and Dinopsyllus lypusus). This phenomenon is vividly apparent in the villages with medium to high plague frequencies. The study suggests that plague surveillance programmes should consider the existing relationship between anthropogenic soils, land

  15. Glycerol reduces food intake in diabetic rats.

    PubMed

    Brief, D J; Davis, J D

    1982-10-01

    Streptozotocin diabetic rats received four daily subcutaneous injections of glycerol or a glycerol solution in place of water for a seven day period. Both night and total food intake in the subcutaneous glycerol group were significantly suppressed below untreated diabetic controls. The oral glycerol group showed a nonsignificant decrease in night foot intake and a significant reduction in day and total food intake. Consumption of additional fluid calories by the oral glycerol group contributed to the suppression of food intake in this group, but suppression in the subcutaneous group was unrelated to calculated calories obtained from glycerol. The oral glycerol group also consumed more of the glycerol solution than the other diabetic groups did of water. Results of this study support previous findings that subcutaneous and oral glycerol suppress food intake in normal rats although suppression with oral glycerol may have related to caloric intake, and suggest that low plasma concentrations of insulin do not interfere with the effects obtained with glycerol in normal animals.

  16. Prenatal buprenorphine exposure decreases neurogenesis in rats.

    PubMed

    Wu, Chih-Cheng; Hung, Chih-Jen; Shen, Ching-Hui; Chen, Wen-Ying; Chang, Cheng-Yi; Pan, Hung-Chuan; Liao, Su-Lan; Chen, Chun-Jung

    2014-02-10

    Perinatal opioid exposure has a negative effect on neurogenesis and produces neurological consequences. However, its mechanisms of action are incompletely understood. Buprenorphine, a mixed opioid agonist/antagonist, is an alternative medication for managing pregnant opioid addicts. This study provides evidence of decreased neurogenesis and depression-like consequences following prenatal exposure to buprenorphine and sheds light on mechanisms of action in a rat model involving administration of intraperitoneal injection to pregnant rats starting from gestation day 7 and lasting for 14 days and a cultured neurosphere model. Results of forced swimming test and tail suspension test showed that pups at postnatal day 21 had worse parameters of depression-like neurobehaviors, independent of gender. Neurobehavioral changes were accompanied by reduction of neuronal composition, biochemical parameters of neural stem/progenitor cells, brain-derived neurotrophic factor (BDNF) expression, tropomyosin-related kinase receptor type B phosphorylation, protein kinase A (PKA) activity, and cAMP response element-binding protein phosphorylation. Results of parallel cell studies further demonstrated a negative impact of buprenorphine on cultured neurospheres, including proliferation, differentiation, BDNF expression and signaling, and PKA activity. Taken together, our results suggest that prenatal exposure to buprenorphine might result in depression-like phenotypes associated with impaired BDNF action and decreased neurogenesis in the developing brain of weanlings.

  17. Mechanical responses of rat vibrissae to airflow

    PubMed Central

    Yu, Yan S. W.; Graff, Matthew M.; Hartmann, Mitra J. Z.

    2016-01-01

    ABSTRACT The survival of many animals depends in part on their ability to sense the flow of the surrounding fluid medium. To date, however, little is known about how terrestrial mammals sense airflow direction or speed. The present work analyzes the mechanical response of isolated rat macrovibrissae (whiskers) to airflow to assess their viability as flow sensors. Results show that the whisker bends primarily in the direction of airflow and vibrates around a new average position at frequencies related to its resonant modes. The bending direction is not affected by airflow speed or by geometric properties of the whisker. In contrast, the bending magnitude increases strongly with airflow speed and with the ratio of the whisker's arc length to base diameter. To a much smaller degree, the bending magnitude also varies with the orientation of the whisker's intrinsic curvature relative to the direction of airflow. These results are used to predict the mechanical responses of vibrissae to airflow across the entire array, and to show that the rat could actively adjust the airflow data that the vibrissae acquire by changing the orientation of its whiskers. We suggest that, like the whiskers of pinnipeds, the macrovibrissae of terrestrial mammals are multimodal sensors – able to sense both airflow and touch – and that they may play a particularly important role in anemotaxis. PMID:27030774

  18. Activation of factor X by rat hepatocytes

    SciTech Connect

    Willingham, A.K.; Matschiner, J.T.

    1986-05-01

    Synthesis and secretion of blood coagulation factor X was studied in hepatocytes prepared by perfusion of rat livers with collagenase. Hepatocytes were incubated in the presence of vitamin K and /sup 3/H-leucine for up to 4h at 37/sup 0/C. Factor X was isolated from the incubation medium by immunochemical techniques and analyzed by SDS-PAGE. The recovered /sup 3/H-labeled proteins migrated, after reduction of disulfides, as two polypeptide chains with apparent molecular weights (M/sub r/) of approximately 42,000 and 22,000 representing the heavy and light chains of factor X respectively. The apparent M/sub r/ of the heavy chain was about 10,000 daltons lighter than seen with the heavy chain of factor X isolated from rat plasma and was more characteristic of the heavy chain of factor Xa. When the levels of factor X secreted by hepatocytes were determined by clotting assays, activity was present as factor Xa. Also, when purified plasma factor X was added to incubations of hepatocytes (>95% parenchymal cells) the added factor X was rapidly converted to factor Xa. Plasma membranes prepared from isolated hepatocytes or from liver homogenates contained an enzyme that converted factor X to factor Xa in a calcium dependent reaction. The physiological significance of a factor X activating enzyme on hepatocyte plasma membranes is not clear.

  19. Rat splanchnic net oxygen consumption, energy implications.

    PubMed Central

    Casado, J; Fernández-López, J A; Esteve, M; Rafecas, I; Argilés, J M; Alemany, M

    1990-01-01

    1. The blood flow, PO2, pH and PCO2 have been estimated in portal and suprahepatic veins as well as in hepatic artery of fed and overnight starved rats given an oral glucose load. From these data the net intestinal, hepatic and splanchnic balances for oxygen and bicarbonate were calculated. The oxygen consumption of the intact animal has also been measured under comparable conditions. 2. The direct utilization of oxygen balances as energy equivalents when establishing the contribution of energy metabolism of liver and intestine to the overall energy expenses of the rat, has been found to be incorrect, since it incorporates the intrinsic error of interorgan proton transfer through bicarbonate. Liver and intestine produced high net bicarbonate balances in all situations tested, implying the elimination (by means of oxidative pathways, i.e. consuming additional oxygen) of high amounts of H+ generated with bicarbonate. The equivalence in energy output of the oxygen balances was then corrected for bicarbonate production to 11-54% lower values. 3. Intestine and liver consume a high proportion of available oxygen, about one-half in basal (fed or starved) conditions and about one-third after gavage, the intestine consumption being about 15% in all situations tested and the liver decreasing its oxygen consumption with gavage. PMID:2129230

  20. Rat tissue reaction to MTA FILLAPEX®.

    PubMed

    Gomes-Filho, João Eduardo; Watanabe, Simone; Lodi, Carolina Simonetti; Cintra, Luciano Tavares Angelo; Nery, Mauro Juvenal; Filho, José Arlindo Otoboni; Dezan, Elói; Bernabé, Pedro Felício Estrada

    2012-12-01

    The aim of this study was to evaluate the rat subcutaneous tissue reaction to implanted polyethylene tubes filled with mineral trioxide aggregate (MTA) FILLAPEX® compared to the reaction to tubes filled with Sealapex® or Angelus MTA® . These materials were placed in polyethylene tubes and implanted into the dorsal connective tissue of Wistar rats for 7, 15, 30, 60, and 90 days. The specimens were stained with hematoxylin and eosin or Von Kossa or left unstained for examination under polarized light. Qualitative and quantitative evaluations of the reaction were performed. All materials caused moderate reactions after 7 days, which decreased with time. The reactions were moderate and similar to that evoked by the control and Sealapex® on the 15th day. MTA FILLAPEX(®) and Angelus MTA caused mild reactions beginning after 15 days. Mineralization and granulation birefringent to polarized light were observed with all materials. It was concluded that MTA FILLAPEX® was biocompatible and stimulated mineralization.

  1. Tropical rat mites (Ornithonyssus bacoti) - serious ectoparasites.

    PubMed

    Beck, Wieland; Fölster-Holst, Regina

    2009-08-01

    In Germany there is limited information available about the distribution of the tropical rat mite (Ornithonyssus bacoti) in rodents. A few case reports show that this hematophagous mite species may also cause dermatitis in man. Having close body contact to small rodents is an important question for patients with pruritic dermatoses. The definitive diagnosis of this ectoparasitosis requires the detection of the parasite, which is more likely to be found in the environment of its host (in the cages, in the litter or in corners or cracks of the living area) than on the hosts' skin itself. A case of infestation with tropical rat mites in a family is reported here. Three mice that had been removed from the home two months before were the reservoir. The mites were detected in a room where the cage with the mice had been placed months ago. Treatment requires the eradication of the parasites on its hosts (by a veterinarian) and in the environment (by an exterminator) with adequate acaricides such as permethrin. PMID:19508683

  2. Skin tumors in aging Long Evans rats.

    PubMed

    Esfandiari, Adeleh; Loya, Theresa; Lee, Jeffrey L

    2002-06-01

    We report 25 cases of skin neoplasm observed among 30 Long Evans rats serving as controls in a psychosocial behavioral study conducted in the Vivarium at Charles R. Drew University, Los Angeles, CA. The animals were 10 weeks old at the beginning of the study. All the skin tumors developed at 18 to 26 months of age and slowly enlarged over a period of 9 months. Multiple nodules occurred in 8 males and 6 females. None of the tumors regressed. The tumors were located around the hind leg and dorso-medial area and measured 1 to 2 cm. Physical examination revealed firm well demarcated dermal masses. Most of the tumor nodules were intradermal, and some had a central ulcerated or keratin-filled core. Microscopic examination performed on some of the tumors showed findings of classic Keratoacanthoma, whereas others showed histologic features suggestive of squamous cell carcinoma. These findings indicate a high rate (83%) of spontaneous skin neoplasms among aging Long Evans rats. To our knowledge, such a high rate of skin neoplasms in aged rodents has not been described in the literature. Furthermore, further studies should be undertaken to confirm these findings and to assess whether these rodents might serve as a model for studying the alterations in the immune system with aging.

  3. Hypertension in rats deficient in copper

    SciTech Connect

    Klevay, L.M.

    1986-03-01

    Male weanling rats were matched into two groups of equal mean weight (48 g), were fed a diet low in copper and zinc and were supplemented with a drinking solution with 10..mu..gZn and 2/sup +/gCu per ml until they grew to approximately 300 g. Systolic blood pressure (mmHg) was measured without anesthesia with an Electro-Sphygmomanometer and pneumatic pulse transducer; no significant difference between groups was found (0 > 0.05). Then copper was omitted from the solution of the group with lower blood pressure in each of two experiments. Plasma cholesterol (mg/dl) was measured by fluorometry and blood pressure was measured again 53 to 86 days later; mean (SE), n = 14, 15. Hypercholesterolemia verified deficiency. Hypotension in copper deficient rats in experiments of others probably was the result of cardiac defects induced in weanling animals. Hypertension joins hypercholesterolemia, hyperuricemia, glucose intolerance and abnormal electrocardiograms as a stigma of copper deficiency. Copper deficiency is the only nutritional insult that induces all of these characteristics useful in predicting risk of ischemic heart disease.

  4. Nuclear microscopy of rat colon epithelial cells

    NASA Astrophysics Data System (ADS)

    Ren, M.; Rajendran, Reshmi; Ng, Mary; Udalagama, Chammika; Rodrigues, Anna E.; Watt, Frank; Jenner, Andrew Michael

    2011-10-01

    Using Nuclear microscopy, we have investigated iron distributions in the colons of Sprague Dawley rats, in order to elucidate heme uptake. Four groups of five Sprague Dawley rats (mean weight 180 g) were fed different purified diets containing either heme diet (2.5% w/w hemoglobin), high fat diet (HFD) (18% w/w fat, 1% w/w cholesterol), 'western' diet (combination of hemoglobin 2.5% and 18% fat, 1% cholesterol) or control diet (7% w/w fat). After 4 weeks, animals were sacrificed by exsanguination after anaesthesia. Thin sections of frozen colon tissue were taken, freeze dried and scanned using nuclear microscopy utilising the techniques PIXE, RBS and STIM. The new data acquisition system (IonDaq) developed in CIBA was used to obtain high resolution images and line scans were used to map the iron distributions across the colon boundaries. The nuclear microscope results indicate that when HFD is given in addition to heme, the iron content of the epithelial cells that line the colon decreases, and the zinc in the smooth muscle wall increases. This implies that the level of heme and fat in diet has an important role in colon health, possibly by influencing epithelial cells directly or changing luminal composition such as bacterial flora or levels of metabolites and cytotoxins.

  5. Load-dependent growth of rat tibia

    NASA Astrophysics Data System (ADS)

    Ohira, Y.; Kawano, F.; Wang, X. D.; Lan, Y. B.; Ishihara, A.; Iwashita, Y.; Majima, H. J.; Nonaka, I.

    Effects of hindlimb suspension or 2-G loading from the postnatal day 4 to month 3 followed by 3 month recovery on tibia and ankle joint mobility were investigated in rats. The dorsiflexion of the ankle was inhibited in the suspended group and such phenomena were irreversible. The growth-related increases of weight and bone mineral density were inhibited by unloading. They were increased gradually, but did not reach the age-matched control levels even after 3 months. Growth of bone length was not affected by unloading. External bending of the shaft and rotation of distal end of tibia were observed in the suspended group and these phenomena did not recover at all. It was suggested that the inhibited dorsiflexion of ankle joints was closely related to such morphological changes. It was further suggested that the unloading-related changes in bone morphology may be caused by abnormal mechanical stress applied by muscles with altered patterns. None of the parameters were influenced by 2-G loading, may be because the mechanical stress applied to bones could be identical at 1- and 2-G, if the rats maintain their posture in a recumbent position with fully dorsiflexed ankle joints.

  6. Calretinin Neurons in the Rat Suprachiasmatic Nucleus.

    PubMed

    Moore, Robert Y

    2016-08-01

    The hypothalamic suprachiasmatic nucleus (SCN), a circadian pacemaker, is present in all mammalian brains. It has a complex organization of peptide-containing neurons that is similar among species, but calcium-binding proteins are expressed variably. Neurons containing calretinin have been described in the SCN in a number of species but not with association to circadian function. The objective of the present study is to characterize a calretinin neuron (CAR) group in the rat anterior hypothalamus anatomically and functionally with a detailed description of its location and a quantitative analysis of neuronal calretinin immunoreactivity at 3 times of day, 0600, 1400, and 1900 h, from animals in either light-dark or constant dark conditions. CAR neurons occupy a region in the dorsal and lateral SCN with a circadian rhythm in CAR immunoreactivity with a peak at 0600 h and a rhythm in cytoplasmic CAR distribution with a peak at 1400 h. CAR neurons should be viewed as an anatomical and functional component of the rat SCN that expands the definition from observations with cell stains. CAR neurons are likely to modulate temporal regulation of calcium in synaptic transmission.

  7. Quantum Relations of the Rat Electroretinogram

    PubMed Central

    Cone, Richard A.

    1963-01-01

    The rat retina is uniform and contains almost exclusively rods. Therefore the rat eye, when uniformly illuminated, produces a gross electroretinogram (ERG) which is simply related to the activity of the individual retinal sources of the ERG. Characteristics of ERG's are shown on an intensity scale of the average number of quanta absorbed per rod per stimulus flash obtained by direct accurate measurement of all quantities involved. An independent check on the accuracy of these measurements is applied to pigment-bleaching data reported by Dowling (1963). When ERG characteristics are placed on this scale it is found that: (a) The b-wave can usually be observed when fewer than one out of two hundred rods absorbs a quantum, the threshold being determined by the noise of the preparation. (b) Near threshold the b-wave amplitude is proportional to intensity. (c) The a-wave appears when there are more than two to four absorptions per rod per flash. (d) The b-wave latency decreases with intensity, and the amplitude becomes proportional to the logarithm of intensity when fewer than one out of ten rods absorbs a quantum. This implies that the b-wave sources must combine excitation from more than one rod (probably more than seven). Therefore the b-wave cannot arise from independent rods or rod-bipolar synapses, but probably reflects activity of entire inner nuclear layer cells. PMID:14043002

  8. Studies of aluminum in rat brain

    SciTech Connect

    Lipman, J.J.; Brill, A.B.; Som, P.; Jones, K.W.; Colowick, S.; Cholewa, M.

    1985-01-01

    The effects of high aluminum concentrations in rat brains were studied using /sup 14/C autoradiography to measure the uptake of /sup 14/C 2-deoxy-D-glucose (/sup 14/C-2DG) and microbeam proton-induced x-ray emission (microPIXE) with a 20-..mu..m resolution to measure concentrations of magnesium, aluminum, potassium, and calcium. The aluminum was introduced intracisternally in the form of aluminum tartrate (Al-T) while control animals were given sodium tartrate (Na-T). The /sup 14/C was administered intravenously. The animals receiving Al-T developed seizure disorders and had pathological changes that included cerebral cortical atrophy. The results showed that there was a decreased uptake of /sup 14/C-2DG in cortical regions in which increased aluminum levels were measured, i.e., there is a correlation between the aluminum in the rat brain and decreased brain glucose metabolism. A minimum detection limit of about 16 ppM (mass fraction) or 3 x 10/sup 9/ Al atoms was obtained for Al under the conditions employed. 14 refs., 4 figs., 1 tab.

  9. Focal embolic cerebral ischemia in the rat

    PubMed Central

    Zhang, Li; Zhang, Rui Lan; Jiang, Quan; Ding, Guangliang; Chopp, Michael; Zhang, Zheng Gang

    2015-01-01

    Animal models of focal cerebral ischemia are well accepted for investigating the pathogenesis and potential treatment strategies for human stroke. Occlusion of the middle cerebral artery (MCA) with an endovascular filament is a widely used model to induce focal cerebral ischemia. However, this model is not amenable to thrombolytic therapies. As thrombolysis with recombinant tissue plasminogen activator (rtPA) is a standard of care within 4.5 hours of human stroke onset, suitable animal models that mimic cellular and molecular mechanisms of thrombosis and thrombolysis of stroke are required. By occluding the MCA with a fibrin-rich allogeneic clot, we have developed an embolic model of MCA occlusion in the rat, which recapitulates the key components of thrombotic development and of thrombolytic therapy of rtPA observed from human ischemic stroke. The surgical procedures of our model can be typically completed within approximately 30 min and are highly adaptable to other strains of rats as well as mice for both genders. Thus, this model provides a powerful tool for translational stroke research. PMID:25741989

  10. Interactions between respiratory oscillators in adult rats

    PubMed Central

    Huckstepp, Robert TR; Henderson, Lauren E; Cardoza, Kathryn P; Feldman, Jack L

    2016-01-01

    Breathing in mammals is hypothesized to result from the interaction of two distinct oscillators: the preBötzinger Complex (preBötC) driving inspiration and the lateral parafacial region (pFL) driving active expiration. To understand the interactions between these oscillators, we independently altered their excitability in spontaneously breathing vagotomized urethane-anesthetized adult rats. Hyperpolarizing preBötC neurons decreased inspiratory activity and initiated active expiration, ultimately progressing to apnea, i.e., cessation of both inspiration and active expiration. Depolarizing pFL neurons produced active expiration at rest, but not when inspiratory activity was suppressed by hyperpolarizing preBötC neurons. We conclude that in anesthetized adult rats active expiration is driven by the pFL but requires an additional form of network excitation, i.e., ongoing rhythmic preBötC activity sufficient to drive inspiratory motor output or increased chemosensory drive. The organization of this coupled oscillator system, which is essential for life, may have implications for other neural networks that contain multiple rhythm/pattern generators. DOI: http://dx.doi.org/10.7554/eLife.14203.001 PMID:27300271

  11. Glucose metabolism in rat retinal pigment epithelium.

    PubMed

    Coffe, Víctor; Carbajal, Raymundo C; Salceda, Rocío

    2006-01-01

    The retinal pigment epithelium (RPE) is the major transport pathway for exchange of metabolites and ions between choroidal blood supply and the neural retina. To gain insight into the mechanisms controlling glucose metabolism in RPE and its possible relationship to retinopathy, we studied the influence of different glucose concentrations on glycogen and lactate levels and CO(2) production in RPE from normal and streptozotocin-treated diabetic rats. Incubation of normal RPE in the absence of glucose caused a decrease in lactate production and glycogen content. In normal RPE, increasing glucose concentrations from 5.6 mM to 30 mM caused a four-fold increase in glucose accumulation and CO(2) yield, as well as reduction in lactate and glycogen production. In RPE from diabetic rats glucose accumulation did not increase in the presence of high glucose substrate, but it showed a four- and a seven-fold increase in CO(2) production through the mitochondrial and pentose phosphate pathways, respectively. We found high glycogen levels in RPE which can be used as an energy reserve for RPE itself and/or neural retina. Findings further show that the RPE possesses a high oxidative capacity. The large increase in glucose shunting to the pentose phosphate pathway in diabetic retina exposed to high glucose suggests a need for reducing capacity, consistent with increased oxidative stress. PMID:16475003

  12. [Sucrose reward promotes rats' motivation for cocaine].

    PubMed

    Li, Yan-Qing; LE, Qiu-Min; Yu, Xiang-Chen; Ma, Lan; Wang, Fei-Fei

    2016-06-25

    Caloric diet, such as fat and sugar intake, has rewarding effects, and has been indicated to affect the responses to addictive substances in animal experiments. However, the possible association between sucrose reward and the motivation for addictive drugs remains to be elucidated. Thus, we carried out behavioral tests after sucrose self-administration training to determine the effects of sucrose experience on rats' motivation for cocaine, locomotor sensitivity to cocaine, basal locomotor activity, anxiety level, and associative learning ability. The sucrose-experienced (sucrose) group exhibited higher lever press, cocaine infusion and break point, as well as upshift of cocaine dose-response curve in cocaine self-administration test, as compared with the control (chow) group. Additionally, despite similar locomotor activity in open field test and comparable score in cocaine-induced conditioned place preference, the sucrose group showed higher cocaine-induced locomotor sensitivity as compared with the chow group. The anxiety level and the performance in vocal-cue induced fear memory were similar between these two groups in elevated plus maze and fear conditioning tests, respectively. Taken together, our work indicates that sucrose experience promotes the rats' motivation for cocaine. PMID:27350195

  13. Pharmacokinetics and biodegradation of chitosan in rats

    NASA Astrophysics Data System (ADS)

    Li, Hui; Jiang, Zhiwen; Han, Baoqin; Niu, Shuyi; Dong, Wen; Liu, Wanshun

    2015-10-01

    Chitosan, an excellent biomedical material, has received a widespread in vivo application. In contrast, its metabolism and distribution once being implanted were less documented. In this study, the pharmacokinetics and biodegradation of fluorescein isothiocyanate (FITC) labeled and muscle implantation administrated chitosan in rats were investigated with fluorescence spectrophotometry, histological assay and gel chromatography. After implantation, chitosan was degraded gradually during its distribution to diverse organs. Among the tested organs, liver and kidney were found to be the first two highest in chitosan content, which was followed by heart, brain and spleen. Urinary excretion was believed to be the major pathway of chitosan elimination, yet 80% of chitosan administered to rats was not trackable in their urine. This indicated that the majority of chitosan was degraded in tissues. In average, the molecular weight of the degradation products of chitosan in diverse organs and urine was found to be <65 kDa. This further confirmed the in vivo degradation of chitosan. Our findings provided new evidences for the intensive and safe application of chitosan as a biomedical material.

  14. Nicotine delays puberty in male rat.

    PubMed

    Londonkar, R L; Sonar, A; Patil, S; Patil, S B

    2000-01-01

    Immature male albino rats, 30 days of age, were treated with 0.3 mg nicotine/100 g body weight either orally or intraperitoneally for 30 days. All the animals were autopsied on the 61 st day, by which time they were sexually mature. Testis, epididymis, seminal vesicle, prostate gland and vas deferens were dissected out, weighed, and processed for biochemical and histological studies. Weight of testis and accessory sex organs of nicotine treated group was significantly reduced. The total cholesterol content was increased while protein, DNA and RNA contents were decreased. The acid phosphatase content was also decreased whereas that of alkaline phosphatase was increased. The surface epithelial cell height of accessory sex organs was decreased along with secretory activity. No spermatozoan was observed in the cauda epididymis of intraperitoneal nicotine treated rats. The changes in the testis and accessory sex organs may be due to reduced output of pituitary FSH and LH which are important to initiate the spermatogenesis and steroidogensis. The absence of spermatozoa in the cauda epididymis and reduction in the activities of accessory sex organs indicates the delay caused by nicotine in the attainment of puberty.

  15. Methylphenidate (Ritalin): behavioral studies in the rat.

    PubMed

    Askenasy, Erik P; Taber, Katherine H; Yang, Pamela B; Dafny, Nachum

    2007-06-01

    Attention Deficit Hyperactivity Disorder (ADHD) is a neuropsychiatric syndrome with an onset in childhood characterized by an inability to remain focused or to concentrate for prolonged periods of time. Children suffering from this disease are many times described as either inattentive or as hyperactive-impulsive depending on what form of the disease they manifest. Methylphenidate is the preferred treatment for this behavioral disorder and is used for long term disease management. Much still remains unknown concerning this stimulant and its effects on behavior and future abuse potential are pertinent questions. Since animal models are used to study the mechanism of drug action and rats are used often in drug studies, the objective of this review is to summarize the research reports that mainly have used rats as the model to investigate the action of methylphenidate. Topics discussed in this review include: (1) What effect does a single dose of methylphenidate have on locomotion activity; (2) Does repeated administration of methylphenidate result in tolerance or sensitization; and (3) Does methylphenidate have rewarding properties as measured by the self-administration and condition placed preference paradigms.

  16. Nitric oxide synthases in pregnant rat uterus.

    PubMed

    Farina, M; Ribeiro, M L; Franchi, A

    2001-03-01

    The conversion of [14C]arginine into [14C]citrulline as an indicator of nitric oxide synthesis was studied in uteri isolated from rats on different days of gestation, after labour and during dioestrus. Nitric oxide synthesis was present in uterine tissues isolated at each stage of gestation and also in tissues collected during dioestrus and after labour. Expression of neuronal nitric oxide synthase was not detectable at any of the stages studied. Endothelial nitric oxide synthase was present at all the stages studied, but there was a significant increase on day 13 of gestation and a decrease thereafter, with the lowest expression recorded on the day after labour. Inducible nitric oxide synthase expression in rat uteri increased substantially during pregnancy, with the highest expression on day 13 of gestation; expression decreased at term and after labour. The changes in expression of inducible nitric oxide synthase were coincident with the changes in nitric oxide synthase activity in uteri treated with aminoguanidine. Thus, these findings indicate that an increase in expression of inducible nitric oxide synthase in the uterus may be important for maintenance of uterine quiescence during pregnancy and its decrease near the time of labour could have an effect on the start of uterine contractility. PMID:11226066

  17. Ideal Experimental Rat Models for Liver Diseases

    PubMed Central

    Lee, Sang Woo; Kim, Sung Hoon; Min, Seon Ok

    2011-01-01

    There are many limitations for conducting liver disease research in human beings due to the high cost and potential ethical issues. For this reason, conducting a study that is difficult to perform in humans using appropriate animal models, can be beneficial in ascertaining the pathological physiology, and in developing new treatment modalities. However, it is difficult to determine the appropriate animal model which is suitable for research purposes, since every patient has different and diverse clinical symptoms, adverse reactions, and complications due to the pathological physiology. Also, it is not easy to reproduce identically various clinical situations in animal models. Recently, the Guide for the Care and Use of Laboratory Animals has tightened up the regulations, and therefore it is advisable to select the appropriate animals and decide upon the appropriate quantities through scientific and systemic considerations before conducting animal testing. Therefore, in this review article the authors examined various white rat animal testing models and determined the appropriate usable rat model, and the pros and cons of its application in liver disease research. The authors believe that this review will be beneficial in selecting proper laboratory animals for research purposes. PMID:26421020

  18. Metabolism and disposition of phenazopyridine in rat.

    PubMed

    Thomas, B H; Whitehouse, L W; Solomonraj, G; Paul, C J

    1993-02-01

    1. The blood profile, tissue distribution, biliary and urinary excretion, and metabolism of 14C-phenazopyridine (PAP) was studied in male Wistar rats. 2. Based on the blood profile of 14C the absorption of PAP from the gastrointestinal tract was rapid; the t1/2 of elimination was 7.35 h. 3. Biliary excretion was a major route of elimination with 40.7% dose excreted by this route in bile duct-cannulated rats over the 0-8 h period. The predominant metabolite was conjugated 4'-hydroxy-PAP. 4. Liver and kidney showed the highest tissue levels of PAP-derived 14C, and significant covalent binding was found in these two tissues. 5. The major urinary metabolite of PAP was 4-acetylaminophenol (NAPA) followed in order by 5,4'-dihydroxy-PAP, 5-hydroxy-PAP, 4'-hydroxy-PAP and 2'-hydroxy-PAP; unchanged PAP accounted for < 1% dose. 6. Doubling the dose of PAP to 200 mg/kg caused a proportionate decrease in urinary NAPA excretion and an increase in 5-hydroxy-PAP.

  19. Genetic Control of Differential Acetylation in Diabetic Rats

    PubMed Central

    Kaisaki, Pamela J.; Otto, Georg W.; McGouran, Joanna F.; Toubal, Amine; Argoud, Karène; Waller-Evans, Helen; Finlay, Clare; Caldérari, Sophie; Bihoreau, Marie-Thérèse; Kessler, Benedikt M.; Gauguier, Dominique; Mott, Richard

    2014-01-01

    Post-translational protein modifications such as acetylation have significant regulatory roles in metabolic processes, but their relationship to both variation in gene expression and DNA sequence is unclear. We address this question in the Goto-Kakizaki (GK) rat inbred strain, a model of polygenic type 2 diabetes. Expression of the NAD-dependent deacetylase Sirtuin-3 is down-regulated in GK rats compared to normoglycemic Brown Norway (BN) rats. We show first that a promoter SNP causes down-regulation of Sirtuin-3 expression in GK rats. We then use mass-spectrometry to identify proteome-wide differential lysine acetylation of putative Sirtuin-3 protein targets in livers of GK and BN rats. These include many proteins in pathways connected to diabetes and metabolic syndrome. We finally sequence GK and BN liver transcriptomes and find that mRNA expression of these targets does not differ significantly between GK and BN rats, in contrast to other components of the same pathways. We conclude that physiological differences between GK and BN rats are mediated by a combination of differential protein acetylation and gene transcription and that genetic variation can modulate acetylation independently of expression. PMID:24743600

  20. Effects of Mild Chronic Intermittent Cold Exposure on Rat Organs.

    PubMed

    Wang, Xiaohui; Che, Honglei; Zhang, Wenbin; Wang, Jiye; Ke, Tao; Cao, Rui; Meng, Shanshan; Li, Dan; Weiming, Ouyang; Chen, Jingyuan; Luo, Wenjing

    2015-01-01

    Cold adaptation is a body's protective response to cold stress. Mild chronic intermittent cold (CIC) exposure has been used to generate animal models for cold adaptation studies. However, the effects of mild CIC exposure on vital organs are not completely characterized. In the present study, we exposed rats to mild CIC for two weeks, and then measured the body weights, the weights of brown adipose tissue (BAT), the levels of ATP and reactive oxygen species (ROS) in the brains, livers, hearts, muscles and BATs. Rats formed cold adaptation after exposure to CIC for two weeks. Compared to rats of the control group that were hosted under ambient temperature, rats exposed to mild CIC showed a lower average body weight, but a higher weight of brown adipose tissue (BAT). Rats exposed to CIC for two weeks also exhibited higher levels of ATP and ROS in all examined organs as compared to those of the control group. In addition, we determined the expression levels of cold-inducible RNA binding protein (Cirbp) and thioredoxin (TRX) in rat tissues after 2 weeks of CIC exposure. Both Cirbp and TRX were increased, suggesting a role of these two proteins for establishment of cold adaptation. Together, this study reveals the effects of mild CIC exposure on vital organs of rats during CIC exposure.