A novel method for induction of salt appetite in rats

A number of procedures exist for the experimental induction of sodium appetite. With the exception of a low sodium diet, nearly all of these methods are invasive, requiring injections, surgery, or both. In addition to stimulating intake of concentrated salt, some of them produce substantial side-effects like reduced food intake and weight gain. The present experiment was designed to evaluate the efficacy of a novel non-invasive method to induce a salt appetite. We investigated the effects of ingesting 100 microM amiloride, a diuretic and natriuretic compound, on urine quantity, electrolyte balance, 0.5 1M sodium chloride (NaCl) intake, water intake, and Na(+)-free chow intake, and weight gain in rats. A water ingestion only group served as control. Consumption of amiloride in mixture with water produced greater loss of urinary Na(+) and intake of 0.51 M NaCl compared with controls. This treatment was without effect on food intake and only modestly influenced weight gain. These results demonstrate a rapid and non-invasive method for the induction of salt appetite free of unwanted side-effects.