Influence of endogenous opiates on the hypotensive action of taurine in DOCA-salt rats.

We studied the role of endogenous opiate activation in the hypotensive action of taurine, a sulphur amino acid, in deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Previous work had shown that supplementation with 1% taurine reduced blood pressure when given after DOCA-salt hypertension had been established. In the present study, in conscious rats, intraperitoneal injection of naloxone, an opiate antagonist, increased blood pressure in taurine-supplemented DOCA-salt rats, but not in DOCA-salt rats or vehicle-treated control rats. These results suggest that activation of an endogenous opiate might contribute to the hypotensive action of taurine in DOCA-salt hypertensive rats.