Attenuated sodium appetite in response to sodium deficiency in Fischer-344 rats.

Fischer-344 (F-344) rats avoid NaCl solutions which are preferred by other strains. The present studies examined Na appetite induced by two methods: maintenance on a Na-deficient diet, and Na depletion by injection of furosemide. In comparison with outbred Wistar rats, F-344 rats showed no evidence of Na appetite induced by Na-deficient diet after the first 15 min (study 1) and demonstrated attenuated Na appetite in response to the natriuretic effects of furosemide (study 2). Since Na loss by Wistar and F-344 rats was similar, it is likely that this reduced Na appetite was due to hedonic differences between the strains rather than to differential renal response to furosemide or Na-deficient diet.