PITUITARY-ADRENAL AND VAGUS MODULATION OF SAUVAGINE-INDUCED AND CRF-INDUCED INHIBITION OF GASTRIC-EMPTYING IN RATS

Sauvagine and CRF significantly delayed gastric emptying in rats: sauvagine was 21 times more potent than CRF in inhibiting gastric emptying when injected subcutaneously and 59 times more potent when injected intracerebroventricularly. The inhibitory effect of intracerebroventricular and subcutaneous injections of sauvagine and CRF was always reversed by vagotomy. Hypophysectomy significantly reduced the inhibitory effect of subcutaneously injected sauvagine and CRF, but not that of intracerebroventricularly injected peptides. Adrenalectomy completely prevented the inhibition of gastric emptying only if it was performed 7 days before peptide administration, whereas the central and peripheral inhibitory effect of sauvagine and CRF was retained after acute (1 h) adrenalectomy. In animals adrenalectomized 7 days previously, chronic administration or a single dose of corticosterone at different intervals (1, 24 and 72 h) before the test caused the peptides to recover their inhibitory activity. These results demonstrate that the inhibitory action of sauvagine and CRF clearly depends on the integrity of the parasympathetic nervous system (vagus), and on corticosterone secretion by the adrenal gland. © 1990.