Does angiotensin regulate systemic conversion of prorenin to renin?
Within 12 hours of binephrectomy in rats, plasma prorenin rises about 250% above the pre-operative baseline and remains above-normal for at least 48 hours, indicating an extrarenal source of prorenin. Concurrently, active renin disappears, implying the loss of a renal "convertase" mechanism for prorenin activation. Such "convertase" activity was detected in incubates of renal cortical slices. To test the effect of angiotensin (Ang) on prorenin/"convertase" regulation, we infused Ang I (100 ng/kg/min) intraperitoneally for 24 hours and obtained evidence of "convertase" inhibition, as happened also following Ang II (2uM) addition to incubated cortical slices. Thus, the release and/or activity of "convertase" appears to be regulated by Ang in-vivo and in-vitro, suggesting that Ang controls not only direct renal renin release but also the secretion and/or activity of a renal "convertase" capable of producing additional renin from circulating prorenin pools.
Ioannou
P
P
Department of Physiology, University of Toronto, Ontario, Canada.
Ismail
R
R
Loh
A Y
AY
Osmond
D H
DH
D000803:Angiotensin I / Q000494:pharmacology; D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D004792:Enzyme Precursors / Q000097:blood / Q000378:metabolism*; D066298:In Vitro Techniques; D007672:Kidney Cortex / Q000187:drug effects / Q000378:metabolism; D008297:Male; D009392:Nephrectomy; D051381:Rats; D011919:Rats, Inbred Strains; D012083:Renin / Q000096:biosynthesis* / Q000097:blood / Q000378:metabolism*
D004792:Enzyme Precursors; D000804:Angiotensin II; D000803:Angiotensin I; D012083:Renin