Testosterone Enhances the Early Onset and Promotes the Increase in Magnitude of Salt-Induced Hypertension in Male Sprague-Dawley Rats.

Abstract

Blood pressure has been reported to be consistently higher in males compared with females from puberty onwards and men show an increased risk for hypertension compared to women, a risk that interacts with genes and with diet. Experiments were designed to assess the effect of testosterone deficiency on blood pressure in male Sprague-Dawley rats on normal or high salt diet. Weanling male rats were randomly divided into 8 groups (n = 6 each) that were either orchidectomised or sham-operated (under ketamine and xylazine anaesthesia), with or without testosterone replacement (10mg/kg sustanon 250® i.m once in 3 weeks), and were placed on normal (0.3%) or high (8%) NaCl diet for 6 weeks. Arterial blood pressure was determined before and weekly throughout the experimental period using non-invasive tail cuff method. There was a significant increase (P < 0.001) in the mean arterial blood pressure of rats placed on high salt diet when compared with control or orchidectomised rats. Orchidectomy elicited a reduction in MABP while testosterone replacement normalized MABP to values observed in intact rats placed on high salt diet. Endogenous testosterone promotes blood pressure-elevating effect of a high salt diet.

Keywords: Orchidectomy, Testosterone Supplementation, Salt-induced Hypertension, Blood Pressure