The Relationship Between Gastric Secretory Inhibition and Cerebral and Gastric Levels of Monoamines in Pylorus-Ligated Rats

Abstract

Neuroleptics, antidepressants and minor tranquilizers were compared quantitatively for the effects on gastric secretion in Shay rats and on barbiturate sleep in mice. In this experiment, it was shown that these two actions of neuroleptics are clearly related and it is suggested that there may be some relationship between these two actions themselves regarding neuroleptics. The antisecretory action of neuroleptics and antidepressants, mentioned above, was reduced in rats pretreated with reserpine. The gastric secretion in Shay rats was clearly enhanced following a single injection of reserpine. This enhanced secretory volume and reduced antisecretory activity of chlorpromazine after reserpine returned to the control concomitantly with the recovery of the cerebral levels of norepinephrine and serotonin and gastric levels of norepinephrine. Antisecretory activity of imipramine and gastric levels of serotonin revealed a more rapid recovery after reserpine treatment. Furthermore, reserpine analogues and p-chlorophenylalanine were studied for the effects on the secretory volume and the antisecretory activity of chlorpromazine in Shay rats and on monoamine contents. It is postulated that the cerebral rather than gastric norepinephrine plays an inhibitory role in gastric secretion in Shay rats and is presumably involved in the antisecretory effect of chlorpromazine, and also possibly that of neuroleptics and antidepressants.