Salt restriction and the voluntary intake of ethanol in rats

Abstract

To investigate the effect of salt restriction on the voluntary intake of ethanol, three groups of rats were offered a choice between ethanol (3%, 6%, or 12% v/v) and water every 3rd day with only ethanol available on the two intervening “forced” days. A fourth group was offered only water throughout. Animals fed a nutritionally adequate diet preferred ethanol in concentrations below 6% (Phase 1) and continued to drink similar amounts of ethanol in Phase 2 when fed only a low-sodium diet. When a brief series of four injections of the salt-losing diuretic furosemide was added to the low-sodium regimen (Phase 3), most rats stopped preferring ethanol and decreased the amount of ethanol they consumed. Upon return to the nutritionally adequate diet (Phase 4), the consumption of ethanol returned to previous levels. Forced-day consumption of ethanol was unaffected by these treatments. Control groups of animals that were offered similar concentrations of ethanol and maintained on the nutritionally adequate diet throughout, but given the diuretic, did not decrease their ethanol consumption. These findings suggest that salt restriction in combination with a diuretic-natriuretic is an effective means to reduce voluntary ethanol intake, and suggest that sodium and/or some aspect of the mechanisms regulating sodium balance may modulate ethanol preference and intake.