[Oral contraceptives, hypertension and nephrosclerosis]

Oral contraceptives are of pathogenetic importance in hypertension of women aged 26 to 35 years. The hypertensive reaction occurs predominantly in those women who have hereditary predisposition to hypertension or diabetes mellitus, who suffer themselves from diabetes or who showed toxemia in previous pregnancies. Our findings are not in agreement with the suggestion that oral contraceptive hypertension in women is always reversible. Simultaneous administration of estrogen and progestogen accelerates Goldblatt-type hypertension in rats. Neither estrogen nor progestogen alone alters arterial blood pressure. In the hormonal combination the hypertensive effect of estrogen can be replaced by epsilon-aminocapronic acid. Estrogen is the only substance increasing plasma renin activity. There is no correlation between the increase of blood pressure and the plasma renin activity in the various groups of experimental animals receiving the different pharmacological substances. Estrogen and the synthetic progestogen cause sodium retention. Because of this, oral contraceptive hypertension may be supposed not to result from a stimulation of the renin-angiotensin-system. Oral contraceptive hypertension may result from a combination of endothelial lesions due to the estrogen's effect on blood coagulation leading to nephrosclerosis, and sodium retention produced predominantly by the synthetic progestogen.