Trayectorias reproductivas, relaciones de género y dinámicas familiares en Uruguay
Abstract (Summary)Introduction: Transplantation of pancreatic islets is an alternative to insulin therapy for the treatment of type I diabetes. Yet this therapy is still at experimental stage and it has yielded worse results than pancreatic transplantation. This is due to different reasons, among them, graft localization. The target organ able to accommodate the islets without further complications is unkown at present. Transplantation into different graft has been experimentally attempted, among them the liver and kidney capsula are the most frequent and those that have yielded the best results. Also, the testicles and brain offer the advantage of being immunologically privileged. Seminal vesicles are even organs offering easy surgical access. Furthermore, they could be considered immunologycally privileged organs because of their role and characteristics. There is no worldwide experience in transplantation of pancreatic islets to seminal vesicles. Hipothesis: Seminal vesicles are well-irrigated and inervated organs, which may be immunologycally privileged. Therefore, Langerhans islets may be implanted and may survive to restore the normoglyicemia in an animal model of experimental diabetis. Objectives: To determine the viability of singenic transplantation of pancreatic islets into diabetic rat seminal vesicles. Material and methods: 158 Lewis singenic male rats were used, weighting between 200 and 400 grams. 49 rats received the transplant. Diabetis was induced with an intraperitoneal dosis of 65 mg/Kg of streptotozine. The pancreas of 98 donor rats were removed from and the islets were purified. An in vitro study demonstrated the correct function of the purified islets as well as the toxicity of collagenase on the islets and the rest of the pancreatic tissue. 800 to 1500 islets from two rats were transplanted into the right seminal vesicle of each receptor rat. A first study consisted on the removal of transplanted vesicles from 6 rats, at 48 and 96 hours, to show their immediate reversion to diabetis. A second study involving 43 receptor rats consisted on a 42-day follow-up to analyze the post-transplant evolution. The vesicles were analyzed by histology and immunohistochemistry (with anti-glucagon and insulin antibodies). The results were compared with a group transplanted on the kidney capsula. Statistic analysis was performed using the SPSS system. Results: The islets worked correctly in vitro, i.e. increasing amounts of glucose induced increased secretion of insulin. The toxicity of collagenase was lower on the islets than on the exocrine tissue and the rest of the pancreatic tissue. Rats became diabetic after the removal of the transplanted vesicles. In the 42 day follow-up, 4 groups could be determined, according to their response. The functional graft (16%), the partially functional graft (partially working or working only during 10 days) (28%), the non-fonctional graft (56%) and the control group. The histology analysis indicated that in the fonctional graft group the islets were implanted into the wall of the vesicle. Those that were transplanted to the kidney capsula (44%) were more successful than those transplanted to the seminal vesicle (16%). Conclusions: Singenic transplantation of pancreatic islets into diabetic rat seminal vesicles is viable, but our results do not improve those achieved by transplantation into the kidney capsula.
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Source Type:Master's Thesis
Keywords:431 departament de geografia
Date of Publication:10/31/2003