Effects of sound stimulus on gastric secretion and plasma corticosterone level in rats

The effects of sound stimulus were studied on the gastric secretion in rats with chronically implanted cannulas. Attempts were made to correlate the changes in the secretion with those of the plasma corticosterone level. Exposure of the animals to sound stimulus (1 hr or 2 hr) produced a marked decrease in gastric secretion and a concomitant increase in plasma corticosterone. It appears that in producing these effects sound stimulus acted as a stressor. Furthermore, a paradoxical increase in secretion was noted in the first hour collection prior to the sound stimulus. This initial increase in secretion may be due to an adaptive compensatory mechanism in anticipation of its marked inhibition.