Effect of azosemide and furosemide on body fluid distribution and vasoactive hormones

We examined the diuretic action of orally administered azosemide (AZ: 60 mg) and furosemide (FM: 40 mg) and their effects on body fluid distribution and circulatory vasoactive hormones in normal male volunters. Urine volume and urinary sodium excretion were increased, peaking during 0 to 2 hours in FM and 2 to 4 hours in AZ in response to administration of both diuretics. The cumulative urine volume and urinary sodium excretion for 8 hours showed no significant difference between AZ and FM. Total body water (TBW) was measured by the dynamic distribution of deuterium oxide and a percentage change in circulating plasma volume (ICG ratio) was determined by using indocyanine green. The decrease in TBW and ICG ratio was detected in proportion to the increase in urine volume after administration of AZ and FM. Plasma renin activity (PRA) and plasma concentration of aldosterone (PAC), angiotensin II (ANG II) and arginine vasopressin (AVP) were elevated in response to the reduction in ICG ratio by both diuretics. The responses of PRA, PAC and ANG II to AZ were delayed about 2 hours as compared with those of FM. The increase in AVP with FM was significantly greater than that with AZ detected 2 hours after administration. The elevation of AVP in AZ was delayed and blunted compared with FM. These data indicate that the difference in diuretic property of AZ and FM may induce different stimulation to the secretion of vasoactive hormones through the changes in body fluid distribution and these hormones might modify the anti-edematic effect of AZ and FM.