Heterogeneity of glycosylation of circulating active and inactive renin

Concanavalin A chromatography was used to examine rat plasma and the incubation medium of rat renal cortical slices, the objective being to assess the heterogeneity of glycosylation of active and inactive renin. Inactive renin was measured by activation with trypsin. Concanavalin A chromatography could separate both active and inactive renin in the plasma into three forms, including the unbound form, the loosely-bound form and the tightly-bound form, thereby suggesting the presence of differently glycosylated forms of active and inactive renin in the plasma. Rat renal cortical slices secreted all these three forms of active and inactive renin, hence these forms are mainly of renal origin. These results suggest that differently glycosylated forms of active and inactive renin are released from the kidney into the blood circulation.