Induction of an appetite for sodium in rats that show no spontaneous preference for sodium chloride solution--the Fischer 344 strain.

Fischer 344 rats show no spontaneous preference for isotonic sodium chloride (NaCl) solution. These experiments indicate, however, that a strong appetite for this solution may be induced by various methods, including adrenalectomy, administration of a mineralocorticoid hormone, acute depletion of sodium, and treatment with inhibitors of the angiotensin I converting enzyme (ACE). These treatments were also shown to produce the expected changes in the renin-angiotensin-aldosterone system, which thus appears to be involved in the induction of an appetite for NaCl solution in this strain of rat. The intakes of NaCl induced in the Fischer 344 rats by these experimental paradigms are less than those that have been reported in either Sprague-Dawley or Wistar strains in similar paradigms. In the case of sodium depletion, the intake of NaCl solution by Fischer 344 rats appears to be more closely related to the deficit than in the other two strains. Thus, the Fischer 344 strain of rats may be a particularly good model for studies of need-related sodium appetite.