The influence of 1-month sex hormones administration on the isolated rabbit vessels reactivity

Abstract

Hyperestrogenemia and change in the estrogen-androgen level ratio in men are supposed to be possible risk factors for several cardiovascular diseases. To study the male rabbit spiral strip reactivity (aorta, renal artery, femoral artery) after 1-month sex hormone administration (estradiol or testosterone twice per week) the method of isomeric contraction was used. The maximal response to noradrenaline, 5-hydroxytryptamine (5-HT) and angiotensin was evaluated. Using RIA method the estradiol and testosterone levels in serum were examined. The estradiol application caused a significant increase of the estradiol level in serum with decrease of testosterone level. The increase of the maximal aorta response to noradrenaline and renal artery response to 5-TH was simultaneously observed. After the testosterone administration an increase of the testosterone level in serum, but without significant change in estradiol level was found. The inhibitory effect of testosterone on the femoral artery was shown by the decrease of the response to 5-HT and angiotensin.