EFFECT OF DEOXYCORTICOSTERONE ACETATE ON BLOOD-PRESSURE IN RELATION TO ACCUMULATION OF LOW-DENSITY-LIPOPROTEIN AND FIBRINOGEN BY AORTA AND OTHER TISSUES OF NORMOTENSIVE WISTAR RATS

Objective To evaluate the effect of different 4-week doses of deoxycor ticosterone acetate (DOCA), together with 0.9% sodium chloride in the drinking water (DOCA-salt) on the blood pressure and on the accumulati on of low-density lipoprotein (LDL) and fibrinogen in artery walls and other tissues in conscious, unrestrained, normotensive Wistar-Kyoto r ats. Methods The accumulation of LDL labelled with I-125 via the adduc t tyramine cellobiose ([I-125]-TC-LDL) and of fibrinogen similarly lab elled with I-131 ([I-131]-TC-fibrinogen) was compared in aortic walls, heart, liver, kidney, lung, skeletal muscle, and adrenal gland tissue s during the final 24 h of a 4-week administration of DOCA-salt, with vehicle-salt and saline as controls. Results In control and vehicle ra ts the blood pressure did not change significantly during the last 5 d ays of treatment. Administration of DOCA-salt produced a dose-dependen t increase in blood pressure during the same period, DOCA-salt adminis tration increased LDL accumulation in the aorta and the heart and decr eased LDL accumulation in the adrenal gland compared with those in rat s of the control and vehicle groups, DOCA-salt administration did not affect fibrinogen accumulation significantly. Conclusion DOCA-salt tre atment produces an increase in arterial blood pressure accompanied by an increase in LDL accumulation by the aortic wall and heart and a dec rease in LDL accumulation by the adrenal gland. These observations rai se the possibility that one mechanism by which hypertension affects at herosclerosis is through increased LDL accumulation in arterial walls.