The differential effects of oestrogens and progestins on vascular tone.

ABSTRACT

The purpose of this paper is to present reported findings of the effects of ovarian steroids on vascular tone. The medical literature was reviewed for relevant contributions. Oestrogen replacement therapy in postmenopausal women is associated with a reduction in mortality from coronary artery disease. Many different cellular actions have been described which help explain the cardioprotective effects of oestrogens, and among these are effects on vascular tone. Oestrogens induce vasodilation through mechanisms involving the arterial endothelium and through endothelial-independent actions. Progestins have varying effects on arterial tone, including induction of vascular smooth muscle relaxation as well as induction of smooth muscle constriction. The effects of oestrogens and progestins on vascular tone are clinically meaningful. Pathophysiological arterial conditions, including angina pectoris and migraine headaches, have been associated with oestradiol deficiency and improvement has been associated with oestradiol replacement. Women with coronary artery disease show improved arterial vasodilator responses after oestradiol treatment which can be reduced by the addition of progestin treatment. Androgens are also vasoactive. Study of the effects of ovarian hormones on vascular tone has become an important area for basic and clinical research.