Saline intake in gerbils (Meriones unguiculatus)

Abstract

Experiment 1 assessed the NaCI preference-aversion function of gerbils on the two-bottle test. The results indicated that gerbils do not show the strong preference for 0.9% NaCI that rats do. There was also no significant difference between the gerbils' intake of 0.9% and 2.0% NaCl. However, there was a significant decrease in the gerbils' saline consumption when the solution was 4.0% by weight. Experiments 2 and 3 demonstrated that the interposition of a single bottle of hypertonic saline prior to the two-bottle test with isotonic saline and water can decrease the gerbils' preference for isotonic saline relative to a control group. This effect depended upon the tonicity of the interposed solution. Although rats show a marked reduction in saline preference following exposure to a single bottle of 2.0% NaCI for 24 h, gerbils do not react similarly. However, when the interposed solution is 4.0% NaCl, gerbils show a subsequent reduction in isotonic saline intake. These results suggest parametric differences between the variables affecting fluid regulation of mesophytic and xerophytic adapted animals which reflect species differences in renal handling of osmotic loads . '