effect of thyroid hormoned on distension-induced gastrik and pepsin secretion in the stomach of rat

thyroid hormoned are known to influence acid and pepsin secretion,though exact mechanism(s) are not fully understood.in this study distention-stimulated acid and pepsin secretionof hypo and hyperthyroid rats were compared with controls.each group consisted of ۸ N-mari rats from both sexs,weighing  ۲۴۶.۶+_۹.۲g. hypo and hyper thyroid states were induced by administration of methimazole(۵۰۰mg/l H۲۰) and thyroxine(۲۰۰mg/l H۲۰) respectively in drinking water.all animals were deprived of food,but not of water ۲۴ hours before the experiments.after anesthesiation with sodium thiopental (۵۰mg/kg body weight,ip),tracheostomy and laparatomy,gastric secretions were collected through a cannula introduced via duodenum.gastric distension was induced by ringer solution in stomach (۱.۵cm/۱۰۰gr body weight).acid secretion which were measured by automatic titrator in the hypothyroid,hyperthyroid and control groups were ۸+_۰.۲,۱۴.۶+_۱.۹,۱۰.۲+_۰.۱ mmol/۱۵min,respectively.pepsin secretion were ۴.۴+_۰.۵,۹.۰۹+_۰.۴ and ۶.۱+_۰.۱ mg/۱۵ min in respective groups.both series show statistically significant differences between control and the other two groups.the results from the measurements of TSH and T۴ hormones show that increased or decreased thyroid function can significantly afeect gastric distension-induced acid and pepsin secretion.