Estudo da densidade das células endócrinas e produtoras de Ghrelina na mucosa gástrica de pacientes portadortes de obesidade mórbida

Abstract

Study of the density of endocrine and ghrelin producer cells in the gastric mucosa of patients with morbid obesity. Belo Horizonte, 2005. Dissertation for M.Sc in Gastroenterology - School of Medicine, UFMG, Brazil. Introduction and objectives: Obesity, a condition defined as the excessive accumulation of adipose tissue, has shown increasing prevalence, and an alarming rate worldwide, with associated comorbidity and high costs. The recent discovery of peptides produced in the digestive tube with a probable role in energy equilibrium, and in particular gastric ghrelin has opened new perspectives of study into possible pathogenic factors of this metabolic disturbance. The objective of the present study was to study the histopathological alterations of the gastric mucosa, in patients with morbid obesity, with emphasis on the presence and characteristics of gastritis and the presence of Helicobacter pylori, as well as, study the population density of endocrine cells in general and of ghrelin cell producers in particular, in the antral and oxyntic gastric mucosa with a control group of functionally dyspeptic patients who were not obese. Patients and methods: Fifty morbidly obese patients, candidates for bariatric surgery, and fifty dyspeptic patients, with BMI <30, underwent upper digestive endoscopy. Fragments of oxyntic and antral gastric mucosa were collected for histological evaluation, silver stained (Grimelius) to study argyrophilic cells and imuno-histochemistry for ghrelin producer cells. Infection by Helicobacter pylori (Hp) was evaluated histologically using Giemsa stain. Results: the histological findings as well as the prevalence of Hp were similar between the morbidly obese patients and the patients who were not obese. The density of argyrophilic cells in the oxyntic mucosa of the obese group of patients was significantly greater in women (p<0.05). The density of immunoreactive cells to ghrelin in the antral mucosa was greater in the obese group of patients (p<0.05) while in the oxyntic mucosa there was no difference. This area had a statistically significant difference between the population of immunoreactive cells to ghrelin in the group of obese patients, being more numerous among women (p<0.05). The density of immunoreactive cells to ghrelin in the oxyntic mucosa was significantly greater among Hp negative patients. There was observed a greater frequency of focal hyperplastic alterations both of the argyrophilic cells as well as immunoreactive cells to ghrelin in the antral mucosa of morbidly obese patients in relation to patients who were not obese (p<0.05). Conclusions: The present study suggests that alterations in the gastrointestinal endocrine cell population and in particular the producer cells of ghrelin, associated with the presence of Hp bacteria, may be associated with individual factors in the physio-pathogenesis of obesity.