DISPROPORTIONAL RELEASE OF DIFFERENTLY GLYCOSYLATED FORMS OF HUMAN RENIN BY FUROSEMIDE

Concanavalin A (con A) chromatography of human plasma revealed the presence of three differently glycosylated forms of active renin (AR) and prorenin (PR), including the con A unbound forms (AR-I and PR-I), the loosely-bound forms (AR-II and PR-II), and the tightly-bound forms (AR-III and PR-III). These three forms of AR and PR were observed in human renal extracts. Normal male volunteers were intravenously given the diuretic furosemide (20 mg), kept standing for one hr and the effect on each form of renin was examined. These treatments elevated the plasma concentrations of AR-I, II and III by 2.1 ± 0.2, 2.6 ± 0.5, and 6.3 ± 1.1-fold, respectively (n=12), thereby indicating that the increase in AR-III was significantly larger than that in the other two forms (P < 0.01). This disproportional increase was accompanied by a significant increase in the relative percent of AR-III in plasma from 21.6 ± 2.5 to 42.2 ± 3.0 % (P<0.01). On the other hand, increase in the plasma levels of PR-I, II, and II was small (1.4 ± 0.1, 1.0 ± 0.1, and 1.1 ± 0.2-fold, respectively). These results provide evidence for the presence of differently glycosylated forms of AR and PR in human plasma and suggest the preferential release of AR-III with the acute stimulation of renin, by furosemide. © 1990.