Hypothalamic ghrelin receptors, weight loss, and glycemia in an experimentally induced obesity model treated by sleeve gastrectomy

Ferreira, Claudia Gissi da RochaRibeiro, André RichterFinck, Christiane MadridPercicote, Ana PaulaMatias, Jorge Eduardo Fouto

ABSTRACT Purpose: Body weight, blood glucose, and hypothalamic ghrelin receptors were monitored in an animal model of obesity after being treated with sleeve gastrectomy. Methods: Forty-two adult male Wistar rats were randomized into two groups: a non-obese group (standard chow); and an obese group, in which obesity was induced by feeding liquid enteral formula Ensure Plus. Each group was divided according to the surgery performed (sham operation or sleeve gastrectomy) and the time of sacrifice after surgery (14 or 28 days). Body weight and capillary blood glucose were monitored throughout the pre- and postoperative periods. Microscopic sections of the parietal cortex, thalamus, hypothalamus, and hippocampus were treated by immunohistochemical reaction with polyclonal anti-ghrelin receptor antibody. Positivity was determined by identifying labeled nuclei and cytoplasm in the brain cells. Results: Sleeve gastrectomy induced effective weight loss (p < 0.001) and reduction in the hypothalamic ghrelin receptor expression (p = 0.04). Weight loss was not directly influenced by the receptor expression. There was no significant impact on capillary glycemia. Conclusion: Sleeve gastrectomy alters GHSR1a receptors, decreasing their expression and body weight. However, weight loss is not directly related to the GHSR1a expression status.