Increased release of gastrin in hyperthyroid rats in vitro.
The extrinsically denervated and vascularly perfused stomach of the hyperthyroid rat exhibits an increased basal gastrin release and an exaggerated response to stimulation with the b-agonist isoproterenol. The b-blocker propranolol does not inhibit the increased basal release of gastrin, but completely blocks the effect of isoproterenol. Vagal stimulation is not different between hyperthyroid and euthyroid rats. We conclude, that there are two mechanisms which are responsible for the increased release of gastrin in hyperthyroidism: firstly a direct effect of thyroid hormones on gastrin cells, and secondly an increase in sensitivity of gastrin cells towards b-adrenergic stimulation.
D000818:Animals; D004558:Electric Stimulation; D005755:Gastrins / Q000378:metabolism*; D006980:Hyperthyroidism / Q000378:metabolism* / Q000503:physiopathology; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
D005755:Gastrins; D011433:Propranolol; D007545:Isoproterenol