MECHANISM OF WEIGHT GAIN SUPPRESSING EFFECT OF ER-40133, AN ANGIOTENSIN I CONVERTING ENZYME INHIBITOR, IN GROWING RATS

Abstract

Effects of ER-40133, an inhibitor of angiotensin converting enzyme (ACE), on weight gain and sodium and potassium balance were studied in growing SD male rats. Thirty-two animals (seven weeks of age) were divided into two groups; one received a standard diet containing 0.227% sodium and the other a low (0.0657%) sodium diet. They were divided into four subgroups; one control group and three treated groups receiving 3, 10 or 30 mg/kg of ER-40133, by gavage, once a day for five consecutive days. Body weight gain (average of the standard and low sodium diet groups) was -32% in the 3 mg/kg group, -74% in 10 mg/kg group and -99% in 30 mg/kg group, when compared with the control group. There was a highly linear correlation between suppression of body weight gain and reduction in sodium and potassium retention for both groups of animals given the standard and low sodium diet. The reduced sodium retention, the primary effect of ACE inhibitors, accounted for about 30% of suppressed weight gain, and the reduced potassium retention, the secondary effect of sodium deficiency, could account for the rest about 70% of weight suppression by ER-40133.