911 resultados para PANCREAS TRANSPLANTATION
Resumo:
Purpose. There is considerable evidence that cellular oxidative stress caused by hyperglycemia plays an important role in the genesis and evolution of chronic diabetic lesions. In this study, we determined the effectiveness of pancreas transplantation (PT) in preventing the imbalance caused by excessive production of reactive oxygen species over antioxidant defenses in lungs of rats rendered diabetic by alloxan injection.Methods. Sixty inbred male Lewis rats, weighing 250-280 g, were randomly assigned to 3 experimental groups: NC, 20 nondiabetic control rats; DC, 20 untreated diabetic control rats; and PT, 20 diabetic rats that received syngeneic PT from normal donor Lewis rats. Each group was further divided into 2 subgroups of 10 rats each which were killed after 4 and 12 weeks of follow-up. Plasma glucose, glycosylated hemoglobin, and insulin levels were determined in all rats. Lipid hydroperoxide (LPO) concentrations and enzyme activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) were measured in the pulmonary tissue of all rats.Results. The DC rats showed elevated blood glucose and glycosylated hemoglobin levels, with insulin blood levels significantly lower than the NC rats (P < .001). They also showed significantly increased LPO concentrations in the lungs (P < .01) after 4 and 12 weeks of follow-up. In contrast, SOD, CAT, and GSH-Px antioxidant activities were significantly reduced in these periods (P < .01) 12 weeks after diabetes induction. Successful PT corrected all clinical and metabolic changes in the diabetic rats, with sustained normoglycemia throughout the study. Excessive lung LPO production and low SOD, CAT, and GSH-Px antioxidant activities were already back to normal 4 weeks after PT.Conclusion. PT can control oxidative stress in pulmonary tissue of diabetic rats. It may be the basis for preventing chronic diabetic lesions in lungs.
Resumo:
Purpose. The impact of pancreas transplantation (PT) on the progression of eye disease is still controversial. This study evaluated the course of retinopathy in transplanted rats in two different diabetic stages.Methods. Sixty inbred male Lewis rats were assigned to four experimental groups: NC-15 nondiabetic control rats; DC-15 untreated diabetic control rats; PT1-15 diabetic rats that received syngeneic pancreas transplants 2 weeks after alloxan diabetes induction; PT2-15 diabetic rats that received pancreas transplants 12 weeks after diabetes onset. Clinical and laboratory parameters and tens opacity were examined in all rats prior to treatment and at 1-, 6-, and 12-months follow-up. Nucleated eyes from five rats in each group processed for ultrastructural study of the retinal at 6 and 12 months after PT or at follow-up.Results. Cataracts were observed in 20%, 60%, and 100% of DC rats at 1-, 6-, and 12-months follow-up, respectively. Early PT (2 weeks) significantly reduced the prevalence of this complication but not late (12 weeks) PT. PT1 rats also showed improved ultrastructure of the superficial and deep capillary plexuses of the retina, and of Muller cells, compared with DC and PT2. In the last group, retinopathy continued to evolve despite successful PT.Conclusion. Our results suggested that prevention of diabetic ocular lesions by PT was closely dependent on earlier performance of the procedure.
Resumo:
Purpose. Oxidative stress is one of the most important mechanisms to explain genesis of the complications in the chronic progression of diabetes. In this investigation we studied the effects of pancreas transplantation (PT) on the imbalance caused by excessive production of free oxygen radicals by antioxidant defenses of rats with serious chronic hyperglycemia induced by alloxan.Methods. Ninety inbred male Lewis rats were randomly distributed into three groups: NC-30 nondiabetic controls; DC-30 diabetic controls without any treatment; PT-30 diabetic rats undergoing syngeneic PT from normal donor Lewis rats. Each experimental group was then split into three subgroups of 10 animals for sacrifice after 1, 3, or 6 months. Clinical and laboratory parameters from all rats as well as lipid hydroperoxide (LPO) concentrations and renal tissue enzyme activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) were recorded for all rats.Results. Successful PT corrected clinical and laboratory alterations in diabetic rats with sustained normoglycemia throughout the study. A significant increase in LPO concentration and a marked reduction in SOD and CAT enzyme activity were observed in DC rats; there was no significant variation in renal tissue GSH-Px in this group. However, alterations in DC rats were completely restored from 1st month after PT; all evaluated enzyme levels did not significantly differ (P < .01) from those in NC controls.Conclusion. Successful PT controlled cellular oxidative stress in diabetic kidneys, which may prevent chronic lesions.
Resumo:
Purpose. The aim of this study was to evaluate whether pancreas transplantation (PT) is a suitable method for controlling histopathologic changes in lungs of alloxan-induced diabetic rats.Methods. Sixty inbred male Lewis rats were randomly assigned to 3 experimental groups: NC, 20 nondiabetic control rats; DC, 20 untreated diabetic control rats; and PT, 20 diabetic rats that received syngeneic PT from normal donor Lewis rats. Each group was further divided into 2 subgroups of 10 rats each, which were killed after 4 and 12 weeks of follow-up. Clinical and laboratory parameters, fresh and fixed lung weights, and fixed lung volumes were recorded for all rats. Total number of alveoli, alveolar perimeter, alveolar surface area, and alveolar epithelial (AE) and endothelial capillary (EC) basal laminae thickening were randomly measured in 5 rats from each subgroup by using an image analyzer. For light microscopy, 250 alveoli were analyzed in each subgroup. For electron microscopy, 50 electron micrographs were examined for each subgroup.Results. The DC rats showed elevated blood glucose and glycosylated hemoglobin levels, with insulin blood levels significantly lower than the NC rats (P < .001). Fresh and fixed lung weights and fixed volumes were significantly reduced in these rats, although their proportions to body weight were increased at 12 weeks (P < .01). The total number of alveoli in diabetic rats was higher than in control rats, whereas alveolar perimeter and surface area were significantly diminished (P < .01). AE and EC basal laminae were significantly thicker in DC than in NC (P < .01). Successful PT corrected all clinical and metabolic changes in diabetic rats, with sustained normoglycemia throughout the study. Morphologic and morphometric changes observed in diabetic lungs were completely prevented in PT rats from 4 weeks after transplant.Conclusion. We conclude that PT can control morphologic and ultrastructural changes in pulmonary parenchyma, suggesting a promising perspective for preventing other chronic diabetic lesions.
Resumo:
A proposição foi realizada, no período pós-operatório imediato, em 40 ratos Wistar, distribuídos por sorteio em doi grupos: grupo NC, vinte ratos correspondentes ao grupo controle, não diabético, submetidos a operação simulada e o grupo PT, 20 ratos correspondentes ao grupo diabético que recebeu transplante de pâncreas heterotópico de ratos Wistar normais. Durante sete dias, antes do transplante, e 1, 3, 6, 12, 24, 48, 72, 96 horas após, determinava-se a glicose sanguínea, a insulina plasnática e o glucagon. Estes parâmetros eram obtidos também do grupo NC. Diabetes mellitus experimental era induzida pela administração intravenosa de aloxana. O grupo PT era imunosuprimido com ciclosporina A. O grupo NC apresentou níveis normais de glicose sanguínea, de insulina plásmica e de glucagon, durante todo o experimento. Foi encontrada nítida hiperinsulinemia no sangue venoso periférico do grupo PT. A insulina plasmática era significantemente maior no grupo PT comparada ao grupo NC começando 72 horas após o transplante. O glucagon plasmático, elevado no período pré-transplante, não se alterou após o transplante. Apesar de hiperinsulinemia e hiperglucagonemia, os níveis de glicose sanguínea eram elevados 6 horas após o transplante e mantiveram-se normais após este período. Considerando-se os níveis de glicose sanguínea 12 horas pós-transplante, não houve diferença estatisticamente significante entre os grupos PT e NC, até o sacrifício.
Resumo:
Groups of inbred alloxan-induced diabetic rats were treated with insulin (I), islets (IT), or pancreas transplantation (PT). Nondiabetic (N) and untreated diabetic (D) control groups were concurrently included. Each group was divided into five subgroups of 10 rats and killed after follow-up of 1, 3, 6, 9, and 12 months. Clinical and laboratory parameters were recorded, and kidney ultrastructural and morphometric analyses performed in each 12-month subgroup, namely glomerular basement membrane (GM) thickening, podocyte number, and number/extension of slit diaphragms (S). Rats from the I group showed poor metabolic control of diabetes compared with N group control rats. However, successfully transplanted rats (IT and PT) had complete restoration to normal levels for all metabolic parameters. GM thickening was significantly higher in diabetic compared with control rats. In contrast, the numbers of podocytes and slits as well as slit extensions were significantly decreased. Insulin therapy did not prevent any alterations upon comparison of diabetic vs control rats. Despite good metabolic control in IT rats, the degree of kidney lesion control never compared with that achieved in PT rats. In this group all glomerular changes were similar to the age-dependent lesions observed in control rats. We conclude that either IT or PT may be a good option for diabetes treatment, although pancreas transplantation seems to be the most effective treatment to control chronic complications.
Effect of pancreas transplantation on the prevention of nephropathy in alloxan-induced diabetic rats
Resumo:
We studied the effects of pancreas transplantation on kidney lesions of rats with alloxan-induced diabetes. Ninety inbred male Lewis rats were randomly assigned to 3 experimental groups: group NC included 30 non-diabetic control rats, group DC included 30 alloxan-induced diabetic control rats, and group PT included 30 alloxan-induced diabetic rats that received pancreas transplants from normal donor Lewis rats. Each group was further divided into 3 subgroups of 10 rats which were sacrificed at 1, 3, and 6 months of follow-up, respectively. Clinical and laboratory parameters during these periods were documented. The kidneys of 5 rats in each subgroup were studied and 50 glomeruli and tubules from each kidney were analyzed by light microscopy by two different investigators in a double-blind study. There was progressive glomerular basement membrane thickening (GBMT), mesangial enlargement (ME), and Bowman's capsule thickening (BCT) in kidneys of rats in the 3 experimental groups during follow-up. These alterations were significantly higher in DC rats (GBMT: 1.99 +/- 0.31; ME: 2.00 +/- 0.33; BCT: 1.88 +/- 0.27) when compared to NC(GBMT: 1.54 +/- 0.30; ME: 1.56 +/- 0.47; BCT: 1.36 +/- 0.35) and PT rats (GBMT: 1.49 +/- 0.29; ME: 1.57 +/- 0.36; BCT: 1.35 +/- 0.28) at 6 months (P<0.01). The extent of GBMT, ME, and BCT observed in DC rats at 1 and 3 months was not significantly different from NC and PT rats. The amount of kidney lesions in PT rats was similar to that of NC rats and lower than those of DC rats at 6 months (P<0.01). In addition, Armanni-Ebstein lesions of the tubules (AE) and tubular lumen protein (PRO) observed in DC rats were not present in NC or PT rats. We conclude that pancreas transplantation in alloxan-induced diabetic rats prevents the development of kidney lesions beginning at 6 months after transplantation.
Resumo:
A 52-yr-old man presented with hematuria and clot retention. He had undergone simultaneous pancreas-kidney transplantation with exocrine pancreas bladder drainage 16 yr ago. The patient suffered from progressive transplant kidney failure with gradually decreasing urine output and needed hemodialysis every other day. Gross hematuria persisted after removal of all blood clots. Cystoscopy showed multiple small, flat ulcers of the bladder mucosa. Some bled discretely and were coagulated cautiously. However, hematuria was refractory to multiple urological interventions, which eventually necessitated an enteric diversion of the exocrine pancreas. Hematuria ceased following an uneventful postoperative course.