The Nature of the Salt Appetite of Adrenalectomized Rats

An increased salt appetite is usually considered to be present when animals, choosing between water and hypertonic NaCl solution (1.8%, 2.7 or 4.5%) drink more of the apparently aversive salt solution than normal animals (1, 5, 7). Overcoming the aversive taste of the concentrated NaCl solution is taken as an expression of motivation for salt intake. We investigated the validity of this assumption. If it is correct, animals with an increased salt appetite should also drink increased amounts of a 0.9% NaCl solution made aversive by adding bitter substances and given as a choice to water, provided that the taste of the NaCl is not masked by the bitter substance. If salt-appetite is regulatory, more bitter 0.9% NaCl than 1.8 or 2.7 NaCl should be chosen by salt-hungry rats.