Intrahypothalamic microinfusion of corticotropin-releasing factor inhibits gastric acid secretion but increases secretion volume in rats.

Bilateral microinfusion of synthetic ovine corticotropin releasing factor (oCRF; 0-4.0 microgram/rat [0-856 pmol/rat]) into the paraventricular nucleus or the ventromedial nucleus of the rat hypothalamus inhibited gastric acid secretion in a dose-related manner. Unexpectedly, these microinfusions both decreased acid concentration and increased secretion volume; total acid output (acid concentration multiplied by secretion volume) was strongly inhibited. In the lateral hypothalamus. CRF microinfusion also both decreased acid concentration and increased secretion volume, but total acid output did not change. oCRF microinfusion into the caudate-putamen did not significantly affect any measure of gastric acid secretion even at the highest dose used. The increased secretion volume seen after oCRF microinfusion is unique; all other centrally acting inhibitors of gastric acid secretion decrease secretion volume. It is possible that hypothalamic CRF may influence gastric secretory function.