Orchidectomy Ameliorates the Vascular Hypertrophic Effect of A High Salt Diet in Sprague-Dawley Rats

Abstract

Sodium overload, which is present in a high salt diet (HSD), induces hypertension by mechanisms that include change in the shear stress and geometric modifications of the blood vessels. Salt sensitivity exhibits sex difference, which is higher in males when compared with
females. This has been attributed to the effect of androgens on blood vessels in males. Therefore, experiments were designed to study the vascular smooth muscle histomorphometry in weanling male rats that were either sham-operated or ochidectomised under (90mg/kg bodyweight ketamine and 10mg/kg bodyweight xylazinei.p) anesthesia, with or without testosterone replacement (TR) (10mg/kg sustanon 250® i.m) once in 3 weeks. They were either placed on a diet with normal 0.3% or high 8% NaCl content for 6 weeks. Histological examination of thoracic aorta and mesenteric artery were carried out with specific dyes; hematoxylin and eosin stain for the cytoplasm and nucleus and Verhoeff – Van Geison and Picro-sirius red stains for elastin and collagen content estimation respectively. Histomorphometric analysis was carried out using a programmed software IMAGE-PRO 3DS 6.1. Tunica media thickness, cross sectional area, elastin and collagen contents of the blood vessels were all significantly elevated (p<0.05) in the rats placed on HSD, while orchidectomy prevented the increase in these parameters but concomitant administration of testosterone restored them to the levels observed in intact rats. Orchidectomy ameliorated vascular hypertrophic effect of a HSD by reducing vascular smooth muscle proliferation and extracellular matrix protein deposition in the blood vessels.

Keywords: Orchidectomy, Testosterone, Vascular hypertrophy, Extracellular matrix protein, media thickness, Histomorphometry