Orogastric determinants of drinking in rats: interaction between absorptive and peripheral controls.

Water intake of water-deprived rats, drinking with absorption prevented by pyloric occlusion, was compared with that of rats drinking normally. Drinking without absorption, under the control of only orogastric factors, was not graded in response to varied deprivation (Experiment 1). Orogastric controls effectively inhibited intake after absorbed water, but not isotonic saline, preloads (Experiment 2). The extent of orogastric inhibition was directly related to absorbed preload volume (Experiment 3). With large absorbed water preloads (9 ml), intakes with and without absorption were equal. Normal function of orogastric controls may thus be based on their interaction with absorption, which progressively enhances peripheral inhibition of drinking.