Multiple factors in the satiation of salt appetite

There is evidence in the literature that has been taken to show that, unlike hunger and thirst, salt appetite cannot be satiated in the absence of salt taste stimulation. The present study showed that repletion of body sodium in the absence of taste stimulation, that is, by gavage, can diminish subsequent saline intake. The satiating effects of gavage versus drinking of saline were studied at various intervals after repletion. For the first few hours, gastric loading was constantly less satiating than was drinking. But as the interval between gavage and testing was lengthened beyond 4-8 hr, the satiating effect began to increase until by 16 hr it was equal to that of drinking. The specificity of the satiating effect of saline gavage as a function of time between treatment and testing was also studied. There appeared to be a transient nonspecific blocking effect of solutes on solute intake which had a duration of less than 30 min. The satiating effect of saline gavage became specific after that time. The experiment suggests that there are multiple factors involved in the satiation of salt appetite--a taste factor, a short-latency post ingestional factor, and a long-latency postingestional factor.