EFFECT OF AMLODIPINE ON BLOOD AND RENAL TISSUE CONCENTRATIONS OF ENDOTHELIN IN MALE RABBITS RECEIVING AN ATHEROGENIC DIET

Introduction: recent studies indicate that endothelin-1 (et-1) and abnormality in the transfer of calcium ions have a role in the atherosclerosis process. amlodipine can influence the risk factors associated with atherosclerosis, but the possible protective mechanisms of et-1 are not known. we evaluated the effects of amlodipine and/or high-cholesterol diet on blood and renal tissue concentration of endothelin, as well as the role of et-1 in the pathophysiology of atherosclerosis in male new zealand white rabbits.methods: thirty-six male new zealand white rabbits were divided into four groups:the normal control group, normal group receiving amlodipine, high-cholesterol diet group and high-cholesterol diet plus amlodipine group. after 8 weeks, all animals were anesthetized and blood or tissues samples were colleted.results: amlodipine led to significant increase in plasma high-density lipoprotein cholesterol (hdl-c) and decrease in serum triglyceride (tg) in the control group. the plasma level of et-1 in the atherosclerotic model group increased significantly compared with the control group (p<0.01). after 8 weeks of treatment with amlodipine, et-1 levels decreased significantly in the control group (p<0.01) and high-cholesterol diet rabbits (p<0.01). amlodipine administration significantly reduced the tissue levels of endothelin only in high-cholesterol diet rabbits (p<0.01). eight weeks of high-cholesterol diet (2%) did not induce any atherosclerotic lesion in this artery, and amlodipine had no significant effect.conclusions: the increase of lipids and et-1 in the renal artery and plasma with a high-cholesterol diet is not linked to the early stages of atherosclerotic plaque formation. amlodipine can reduce levels of et-1 and lipids, but the mechanisms remain to be determined.