Renin Dependence of Insulin-Induced Thirst

The Effects of Centrally Administered Porcine Relaxin on Drinking Behaviour in Male and Female Rats

“…It clearly will be of interest to determine whether systemic relaxin causes increased drinking and whether or not a dose-response relation exists as is the case for the inhibition of the milk-ejection reflex. In the experiments described here, ICV insulin had no effect on drinking behaviour, but when it is given systemically it is dipsogenic, though the effect is in part mediated through the renal renin-angiotensin system, which is activated by hypoglycaemia (13). It is likely that inhibition of the milk-ejection reflex depends on the receptors for insulin-like growth factors which have been found in the circumventricular organs ( 14), since lesions of the subfornical organ eliminated the inhibitory effect of intravenous or ICV relaxin (15).…”

“…Insulin, which is similar in structure and molecular weight to relaxin, was without effect on drinking when doses comparable to dipsogenically effective doses of relaxin were injected ICV. In male Wistar rats treated with DOCA for [5][6][7][8][9][10][11][12][13][14][15] days, relaxin retained its weak stimulatory action on water intake but did not affect NaCl intake despite the increased baseline NaCl intake during DOCA. These results indicate that relaxin is a dipsogen in the rat but that it seems to have little short-term effect on sodium appetite.…”