Effect of angiotensin II upon platelet adhesiveness and the thrombelastogram in patients with essential arterial hypertension.

Platelet adhesiveness increases significantly after angiotensin II administration, in pressor and subpressor doses, only in the hypertensive patients with urinary infection. The k index on the thrombelastogram decreases significantly following angiotensin II infusion in pressor doses both in the hypertensive patients with urinary infection and in those without urinary infection. At the same time, angiotensin II infusion in pressor and subpressor doses determines a significant increase of epsilon index in both hypertensive patients with urinary infection and in those without urinary infection. These results pose the problem of thrombocyte sensitization by the urinary infection to the vasopressor substance. The increased tendency to thrombosis by angiotensin, in hypertensive patients with urinary infection, could constitute a mechanism of malignant transformation of arterial hypertension.