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| Author(s): |
Eduardo Rebelato Lopes de Oliveira
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI) |
| Defense date: | 2010-06-24 |
| Examining board members: |
Angelo Rafael Carpinelli;
Fernando Rodrigues de Moraes Abdulkader;
Everardo Magalhães Carneiro;
Rui Curi;
Francisco Rafael Martins Laurindo
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| Advisor: | Angelo Rafael Carpinelli |
| Abstract | |
The effect of changes in the oxidation/reduction (redox) state over pancreatic islet function was analyzed by shifts toward oxidative or reducing environments. Pancreatic cell function was analyzed by glucose-stimulated insulin secretion (GSIS), glucose metabolism and intracellular calcium oscillations. Redox modulation favoring the oxidative state inhibited pancreatic cell function. However, the suppression of the oxidative state by antioxidant treatment exerted a dual effect on pancreatic <font face=\"Symbol\">β cell function, where small changes were positively correlated with an increase in insulin secretion, while higher changes suppressed GSIS. Additionally, the reactive oxygen species (ROS) content was modulated by changes in glucose concentration. Increasing concentrations of glucose acutely suppressed ROS content, what was correlated with the activation of the NADPH source, the pentose-phosphate pathway. Thus, the intracellular adjustment of ROS content may be part of the insulin secretion mechanism in response to glucose. (AU) | |