Hypertonic NaCl inhibits gastric motility and food intake in rats with lesions in the rostral AV3V region.

Abstract

Several diverse treatments that stimulate pituitary secretion of oxytocin (OT) in rats produce a parallel inhibition of gastric motility and food intake. The present experiments demonstrate that injection of hypertonic saline (HS) is another such treatment. Systemic administration of large doses of OT had no effect on gastric motility. Lesions within the region anteroventral to the third ventricle (AV3V region) severely impaired the drinking response to HS without affecting its inhibition of either gastric motility or food intake. These and other results suggest that despite the close association of pituitary secretion of OT with inhibition of both gastric motility and food intake in intact animals after HS administration, these effects may be dissociated by lesions within the AV3V region. Consequently, osmosensitive cells located within the periventricular tissue of the rostral AV3V region, which are critical for the stimulation of thirst and pituitary OT secretion after systemic injection of HS, do not appear to be essential for the parallel inhibition of gastric motility and food intake produced by this treatment in rats.