Thyrotrophin-releasing hormone inhibits the pentagastrin stimulated gastric secretion in man. A dose response study

Actions of thyrotrophin-releasing hormone (TRH) have generally been confined to the central nervous system (CNS). We have studied the effect of increasing doses of TRH i.v. (8, 40, 200 and 1000 microgram/h) on pentagastrin-stimulated gastric secretion in ten normal individuals. All doses caused stepwise inhibition of gastric juice (volume), acid and pepsin output. When employing the largest dose of i.v. TRH (1000 microgram/h) the inhibition was 44% for gastric volume, 51% for acid output and 57% for pepsin output. This study shows that TRH inhibits gastric secretion, and indicates that TRH has actions outside the CNS in man.