The bank vole (Microtus arvalis) develops glucose intolerance both when kept in captivity and in the wild state. Glucose intolerant bank voles kept in captivity exhibited polydipsia, polyuria, hyperglycemia, hyperinsulinemia, islet autoantibodies and a markedly changed islet structure resembling so–called hydropic degeneration. Islets showing hydropic degeneration have reduced β–cell mass. However, the relative islet size to total pancreas area was not changed. Pancreatic islet isolated from glucose intolerant bank voles had an altered islet function showing signs of being exposed to an increased functional demand on their β–cells. Also, islets from male bank voles seem more affected than the islets from females. Islets isolated from glucose tolerant male bank voles cultured for 5 days at 28 mM glucose did not reveal any change in insulin gene expression or insulin biosynthesis rate. However, islets from female bank voles displayed a glucose concentration dependent response. This suggests that there is gender difference in that, islets of female more easily than islets of males adapt to elevated glucose concentration. Furthermore, islets isolated from glucose tolerant males had reduced insulin gene expression after exposure to proinflammatory cytokines for 48 hrs. This effect seemed to be NO-independent since only a minor elevation of nitrite accumulation in the medium was seen, and the use of iNOS inhibitor could not counteract the cytokine effect. The observed response seen in bank vole islets upon exposure to various glucose concentrations or proinflammatory cytokines is similar to those seen in studies of human islets. The bank vole may therefore represent a novel animal model for the study of diabetes. An unresolved issue is the role of the Ljungan virus which is found in the bank vole colony. Bank voles developing glucose intolerance display features of both human type 1 and type 2 diabetes, where environmental factors seems to play an important role as determinant. Our findings suggest that bank voles bred in the laboratory may develop more of a type 2 diabetes. However, bank voles caught in nature instead may rather develop a type 1 form of the disease.

Made available in DSpace on 2016-01-26T18:55:43Z (GMT). No. of bitstreams: 1 Matheus Parra.pdf: 726860 bytes, checksum: fe316e1bd808b08f513b45b186081bcc (MD5) Previous issue date: 2015-02-11 / The objective was to evaluate the effect of probiotic on renal function in intoxicated Wistar rats by potassium dichromate (K2Cr2O7). We used 80 male Wistar rats, that were 21 to 25 days old, randomly divided into two treatments (n = 40 rats/treatment). In the DK treatment the animals consumed 0, 12, 24 and 36 mg of K2Cr2O7 added to the diet and in the DK+P treatment the rats consumed 0, 12, 24 and 36 mg of K2Cr2O7 in the diet with 0.2% probiotic. Those animals consumed their respective diets for 90 days, then, they were euthanized by exsanguination and blood samples were taken to evaluate serum creatinine and urea levels and histopathological analysis of the kidneys were realized. Serum creatinine levels in the DK+P treatment was significantly (p<0.05) lower in relation to the DK treatment in all dichromate doses analyzed. Serum urea levels did not differ significantly (p>0.05) between the DK and DK+P treatments. There was no significant difference (p>0.05) in serum creatinine and urea concentrations in the rats that consumed 0 and 12 mg of dichromate and probiotic, but in the other animals serum creatinine and urea increased significantly (p<0.05) along with increasing doses of the dichromate in both experimental treatments. The rats in DK and DK+P treatments showed hydropic degeneration in renal tubules at all doses of K2Cr2O7. The DK treatment rats showed interstitial nephritis. It was concluded that supplementation with the probiotic was beneficial for glomerular filtration in rats intoxicated with low doses of potassium dichromate, but did not prevent the tubular hydropic degeneration in Wistar rats intoxicated by potassium dichromate. / Objetivou-se avaliar o efeito de probiótico na função renal de ratos Wistar intoxicados por dicromato de potássio (K2Cr2O7). Utilizou-se 80 ratos Wistar, machos com 21 a 25 dias, divididos aleatoriamente em dois tratamentos (n=40 ratos/tratamento). No tratamento DK os animais consumiram 0, 12, 24 e 36 mg de K2Cr2O7 adicionado na dieta e o tratamento DK+P os ratos consumiram 0, 12, 24 e 36 mg de K2Cr2O7 na dieta com 0,2% de probiótico. Esses animais consumiram suas respectivas dietas durante 90 dias, foram eutanasiados por exsanguinação e colhidas amostras de sangue para realização de dosagem sérica de creatinina e uréia e realizou-se nos rins análise histopatológico. A creatinina sérica do tratamento DK+P foi significativamente (p<0,05) menor em relação ao tratamento DK em todas as doses de dicromato estudadas. A uréia sérica não diferiu significativamente (p>0,05) entre os tratamentos DK e DK+P. Não houve diferença significativa (p>0,05) na concentração sérica de creatinina e uréia dos ratos que consumiram 0 e 12 mg de dicromato e probiótico, mas dos demais animais a creatinina e uréia sérica aumentou significativamente (p<0,05) juntamente com as doses crescentes de dicromato estudadas em ambos os tratamentos experimentais. Os ratos dos tratamentos DK e DK+P apresentaram degeneração hidrópica nos túbulos renais em todas as doses estudadas de K2Cr2O7. Os ratos do tratamento DK apresentaram nefrite intersticial. Conclui-se que a suplementação com probiótico foi benéfica para a filtração glomerular nos ratos intoxicados com baixa dose de dicromato de potássio, mas não evitou a degeneração hidrópica tubular nos ratos Wistar intoxicados pelo dicromato de potássio.

Made available in DSpace on 2016-07-18T17:53:14Z (GMT). No. of bitstreams: 1 Matheus Parra.pdf: 726860 bytes, checksum: fe316e1bd808b08f513b45b186081bcc (MD5) Previous issue date: 2015-02-11 / The objective was to evaluate the effect of probiotic on renal function in intoxicated Wistar rats by potassium dichromate (K2Cr2O7). We used 80 male Wistar rats, that were 21 to 25 days old, randomly divided into two treatments (n = 40 rats/treatment). In the DK treatment the animals consumed 0, 12, 24 and 36 mg of K2Cr2O7 added to the diet and in the DK+P treatment the rats consumed 0, 12, 24 and 36 mg of K2Cr2O7 in the diet with 0.2% probiotic. Those animals consumed their respective diets for 90 days, then, they were euthanized by exsanguination and blood samples were taken to evaluate serum creatinine and urea levels and histopathological analysis of the kidneys were realized. Serum creatinine levels in the DK+P treatment was significantly (p<0.05) lower in relation to the DK treatment in all dichromate doses analyzed. Serum urea levels did not differ significantly (p>0.05) between the DK and DK+P treatments. There was no significant difference (p>0.05) in serum creatinine and urea concentrations in the rats that consumed 0 and 12 mg of dichromate and probiotic, but in the other animals serum creatinine and urea increased significantly (p<0.05) along with increasing doses of the dichromate in both experimental treatments. The rats in DK and DK+P treatments showed hydropic degeneration in renal tubules at all doses of K2Cr2O7. The DK treatment rats showed interstitial nephritis. It was concluded that supplementation with the probiotic was beneficial for glomerular filtration in rats intoxicated with low doses of potassium dichromate, but did not prevent the tubular hydropic degeneration in Wistar rats intoxicated by potassium dichromate. / Objetivou-se avaliar o efeito de probiótico na função renal de ratos Wistar intoxicados por dicromato de potássio (K2Cr2O7). Utilizou-se 80 ratos Wistar, machos com 21 a 25 dias, divididos aleatoriamente em dois tratamentos (n=40 ratos/tratamento). No tratamento DK os animais consumiram 0, 12, 24 e 36 mg de K2Cr2O7 adicionado na dieta e o tratamento DK+P os ratos consumiram 0, 12, 24 e 36 mg de K2Cr2O7 na dieta com 0,2% de probiótico. Esses animais consumiram suas respectivas dietas durante 90 dias, foram eutanasiados por exsanguinação e colhidas amostras de sangue para realização de dosagem sérica de creatinina e uréia e realizou-se nos rins análise histopatológico. A creatinina sérica do tratamento DK+P foi significativamente (p<0,05) menor em relação ao tratamento DK em todas as doses de dicromato estudadas. A uréia sérica não diferiu significativamente (p>0,05) entre os tratamentos DK e DK+P. Não houve diferença significativa (p>0,05) na concentração sérica de creatinina e uréia dos ratos que consumiram 0 e 12 mg de dicromato e probiótico, mas dos demais animais a creatinina e uréia sérica aumentou significativamente (p<0,05) juntamente com as doses crescentes de dicromato estudadas em ambos os tratamentos experimentais. Os ratos dos tratamentos DK e DK+P apresentaram degeneração hidrópica nos túbulos renais em todas as doses estudadas de K2Cr2O7. Os ratos do tratamento DK apresentaram nefrite intersticial. Conclui-se que a suplementação com probiótico foi benéfica para a filtração glomerular nos ratos intoxicados com baixa dose de dicromato de potássio, mas não evitou a degeneração hidrópica tubular nos ratos Wistar intoxicados pelo dicromato de potássio.