Active and inactive renin release from rabbit kidney cortex slices: effect of sodium concentration and of furosemide.

Publisher Website
Google Scholar
Abstract
Active and inactive renin release by rabbit kidney cortex slices was investigated. Inactive renin was estimated as the increase in renin activity after acidification (pH 2.8) of slice supernatant solutions. Active renin release was increased when incubation medium [Na+] was reduced. This relationship was linear (r2 = 0.96) over the range [Na+] = 23-133 mM. For the same range of [Na+] inactive renin secretion decreased when medium [Na+] was reduced (r2 = 0.92). Therefore, the proportion of total renin which was in the active form decreased linearly as [Na+] was reduced (r2 = 0.97). Chloride ions did not appear to be important in altering the secretion of either active or inactive renin. Adding furosemide to the incubation medium concentration up to 40 .mu.g/ml did not change secretion of either form of renin. The action of furosemide on secretion of active and inactive renin in vivo is therefore secondary to altered renal function. Regulation of the relative amount of active and inactive renin in plasma could be entirely an intrarenal event. It is not essential to invoke a plasma activating enzyme for inactive renin to explain changes in plasma levels of the 2 forms of renin. Release of inactive renin by the kidney apparently is controlled by a Na-sensitive mechanism.