Hoe 140 abolishes the blood pressure lowering effect of taurine in high fructose-fed rats

Summary. High fructose feeding induces moderate increases in blood pressure of normal rats, associated with hyperinsulinemia, insulin resistance and impaired glucose tolerance. Increased vascular resistance, and sodium retention have been proposed to contribute to the blood pressure elevation in this model. Taurine, a sulphur-containing amino acid has been reported to have antihypertensive and antinatriuretic actions. In addition, taurine is shown to increase the excretion of nitrite and kinin availability and hence would be expected to improve the vascular tone. In the present study, the involvement of kinins in the blood pressure lowering effect of taurine was investigated by coadministration of Hoe 140, a kinin B₂ receptor antagonist along with taurine. The effects of taurine on plasma and urinary concentrations of sodium and tissue kallikrein activity were studied in high fructose-fed rats. Fructose-fed rats had elevated blood pressure and decreased levels of sodium in urine. Treatment with 2% taurine in drinking water prevented the blood pressure elevation and coadministration of Hoe 140 abolished this effect of taurine in high fructose-fed rats. The findings confirm the antinatriuretic action of taurine and also suggest a role for the kinins in the mechanism of taurine action in diet-induced hypertension.