Na deficiency and other physiological influences on voluntary Na intake of BALB/c mice.

BALB/c mice exhibited a small hedonic intake of 0.3 M NaCl, which was not influenced by change from high to low salt diet or by withholding access to NaCl solution for 1 day. Sodium deficiency produced by furosemide injection consistently caused a highly significant increase in sodium intake. Sodium deficiency was corrected rapidly over 10 min. The appetite was specific for sodium in a cafeteria experiment and was exhibited by naive animals on the first experience of sodium deficiency and subsequent access to salt. The appetite was significantly related to the extent of body deficit, but overdrinking proportionate to initial deficit was characteristic. No increase in sodium intake occurred with repeated experience of sodium deficit. Water deprivation caused a subsequent increase of sodium intake. Total deprivation of food for 48 h caused a large sustained increase of sodium intake, but reduction of food intake by 40% did not influence sodium appetite.