THE EFFECTS OF ANTIHYPERTENSIVE DRUGS ON THE KIDNEY VASCULAR COMPLICATIONS OF HYPERTENSION IN THE SPONTANEOUSLY HYPERTENSIVE RAT

The aim of this study was to examine the effects of antihypertensive d rugs on the kidney blood vessels in spontaneously hypertensive rats. T hree antihypertensive drugs with different mechanisms of action were u sed: the beta adrenergic blocker-propranolol, the vasodilatator-hydral azine and an inhibitor of the angiotensin I converting enzyme-captopri l. They were given to the rats in tap water every day, during 5 weeks. Every week during the experiment, arterial blood pressure was measure d by an indirect method and heart rate was calcilated for each animal (including the control group). Finally, the rats were sacrificed and p ieces of kidney were taken for pathohystological and morphometric anal ysis of interlobular arteries. After 5 weeks of treatment, the results wereas follows in all three experimental groups, arterial blood press ure was decreased comparing to the control group; there was no correla tion between the level of blood pressure and the degree of damage to t he blood vessels. The drug which decreased arterial pressure the most was hydralazine, but it did not affect the degree of damage to kidney blood vessels. Captopril was very effective both in decreasing the blo od pressure and lowering the degree of damage to kidney blood vessels, while propranolol did not have a great effect either on the arterial blood pressure of on vascular changes in kidneys. The results showed t hat arterial blood pressure was not the only factor in the genesis of vascular complications, became other factors, like the renin-angiotens in system, also have an importent role in that process (the results sh owed that captopril had the greatest protective effect concerning dama ge to the blood vessels, but it did not have the greatest effect in de creasing of arterial blood pressure).