Salt appetite induced by DOCA treatment or adrenalectomy in rats: analysis of ingestive behavior.

A detailed description of the increased intake of 0.5 M NaCl solution by rats after systemic treatment with desoxycorticosterone acetate (DOCA) or after adrenalectomy was obtained by measuring feeding and drinking activity every 6 s for 23 h. In both models of salt appetite, the induced increase in saline intake occurred mostly at night and in close temporal association with bouts of eating and water drinking rather than in isolation. Consequently, there was no significant change in the total number of ingestive episodes, despite the substantial increase in the number of saline bouts. Saline drinking was in small draughts that usually were preceded by food bouts and followed promptly by water bouts. These and other observations indicate that under standard maintenance conditions of ad lib access to food and fluids, adrenalectomy and DOCA treatment each produce a relatively weak stimulus of salt appetite, and large daily intakes accrue because the animals do not remain satiated and the appetite recurs repeatedly.