AJP - Regulatory, Integrative and Comparative Physiology, Vol 241, Issue 3 233-R239, Copyright © 1981 by American Physiological Society
Zinc nutrition and salt preference in rats
W. Jakinovich Jr and D. W. Osborn
Zinc-deficient rats have an increased preference for sodium chloride
(saltwater). We investigated the possibility that this elevated saltwater
preference is due to nonfunctional taste receptors. In experiment I,
zinc-deficient rats consumed more saltwater than zinc-sufficient rats at
most sodium chloride concentrations tested (0.001-1.0 M). When the
zinc-deficient rats were fed a zinc-sufficient diet, the clinical symptoms
of zinc deficiency rapidly disappeared. However, the rats still preferred
saltwater to a greater extent than rats maintained on the zinc-sufficient
diet. In experiment II, rats fed diets supplemented with levels of zinc
below the requirement for maximum growth had an increased preference for
saltwater (0.15 M NaCl). In experiment III, electrophysiological responses
of the taste nerves to various concentrations of sodium chloride, sucrose,
quinine . HCl, and hydrochloric acid were the same in both zinc-deficient
and zinc-sufficient rats. We conclude that the taste receptor sensitivity
of the rat is not impaired by zinc deficiency. The increased salt
preference of zinc-deficient rats might be related to some endocrine or
central nervous system disorder precipitated by inadequate dietary zinc.
