Inhibition of hypertension and salt intake by oral taurine treatment in hypertensive rats.

Effects of oral treatment with taurine on fluid intakes produced by renin were assessed in spontaneously hypertensive rats of the Okamoto strain (SHR). Renin injected into the preoptic area increased water intake and evoked salt (2.7% NaCl solution) intake, and angiotensin II injected into this area increased water intake, but not salt intake, in both SHR and control normotensive Wistar-Kyoto rats (WKY). The salt intake elicited by renin, but not water intake produced by renin or angiotensin II, was potentiated in SHR. These effects of renin and angiotensin II on fluid intakes were antagonized by previous administration of taurine or gamma-aminobutyric acid into the cerebral ventricles in both strains. When SHR received water containing 3% taurine from 32 to 105 days of age, development of hypertension was inhibited. Renin administered into the preoptic area at 105 days of age caused an increase in salt intake, but the increase was markedly inhibited by the oral administration of taurine as well. These results show that salt appetite produced by centrally administered renin is exaggerated in SHR and that development of hypertension as well as renin-induced salt appetite in SHR is inhibited by dietary taurine.