ANTIHYPERTENSIVE DRUGS AND ENDOTHELIAL-CELL FUNCTION

Arterial hypertension is associated with increased capillary permeabil ity, a possible contributor to the vascular remodelling process which could be involved in certain pathological conditions arising from elev ated blood pressure. This study evaluated the effects of various antih ypertensive drugs on capillary permeability in the normal rat, using E van's blue dye (EB) as a marker of albumin extravasation. The results reveal that acute injection of certain diuretics (furosemide, indapami de, hydrochlorothiazide) increase while others (amiloride, cicletanine ) decrease capillary permeability via stimulation of the cyclooxygenas e pathway. 10 day gavage with indapamide, amiloride and cicletanine, a s well as angiotensin-converting enzyme (ACE) inhibitor perindopril an d calcium channel blockers nifedipine and verapamil decreases capillar y permeability, whereas furosemide, hydrochlorothiazide, ACE inhibitor captopril and calcium channel blocker clentiazem do not modify or inc rease EB extravasation. Hence, selected antihypertensive agents reduce capillary permeability and could therefore have a supplemental protec tive vascular effect, in addition to their lowering arterial pressure.