CASTRATION LOWERS AND TESTOSTERONE RESTORES BLOOD-PRESSURE IN SEVERALRAT STRAINS ON HIGH SODIUM DIETS

The objective of this study was to determine the effect of a high sodi um diet and prepubertal castration (5-6 weeks) and androgen replacemen t therapy on blood pressure in male normotensive, borderline hypertens ive and hypertensive rats on a high sodium diet between 9-22 weeks of age. The strains used were: Wistar Kyoto-(WKY), spontaneously hyperten sive rat-(SHR), and borderline hypertensive rat-(BHR). Castration sign ificantly reduced blood pressure (20-30mmHg) and testosterone replacem ent in castrated males restored blood pressure in all strains. Plasma norepinephrine (NE) increased with castration in the WKY and SHR strai ns but decreased in the BHR. However, there was a significant elevatio n in all strains between the midpoint and endpoint NE values. The high sodium diet did not prevent the blood pressure lowering effect of cas tration.