title: The effects of angiotensin II, saralasin, and furosemide on inactive renin in the fetal lamb.
abstract: The effects of angiotensin II, saralasin, and furosemide on plasma prorenin (inactive renin, cryoactivated, and trypsin activated) were studied in the fetal lamb. Cryorenin and trypsin-activated renin decreased from 4.0 +/- 1.0 ng/ml/hr of plasma renin activity (PRA) and 7.3 +/- 1.0 to 0.05 +/- 0.01 and 1.7 +/- 1.0 (P less than 0.01), respectively, after 15 min of angiotensin II infusion; active renin did not statistically decrease. Cryoactivated and trypsin-activated renin increased from 2.2 +/- 0.5 ng/ml/hr (mean +/- S.E.) and 4.9 +/-  0.9 of PRA to 4.6 +/- 1.0 and 8.5 +/0 1.5, respectively, after 30 min (P less than 0.05) of the saralsin (10 micrograms/kg/min) infusion, whereas active renin showed no change. Furosemide increased cryorenin and trypsin-activated renin in parallel to active renin from 2.9 +/- 1.1 ng/ml/hr and a6.9 +/- 1.5 of PRA to 5.0 +/- 1.0 and 11.2 +/- 1.5 at 65 min, respectively (P less than 0.05). These data show that prorenin levels are high in the fetal lamb, angiotensin II can inhibit prorenin but not renin, and a negative feedback loop exists between angiotensin II and prorenin, but not renin.
mesh_terms: D000804:Angiotensin II / Q000031:analogs & derivatives* / Q000494:pharmacology*; D000818:Animals; D003080:Cold Temperature; D004357:Drug Synergism; D004789:Enzyme Activation / Q000187:drug effects; D004792:Enzyme Precursors / Q000037:antagonists & inhibitors / Q000097:blood*; D004794:Enzyme Repression / Q000187:drug effects; D005260:Female; D005312:Fetal Blood / Q000201:enzymology*; D005665:Furosemide / Q000494:pharmacology*; D011247:Pregnancy; D012083:Renin / Q000097:blood*; D012504:Saralasin / Q000494:pharmacology*; D012756:Sheep; D014357:Trypsin / Q000494:pharmacology
chemical_list: D004792:Enzyme Precursors; D000804:Angiotensin II; D005665:Furosemide; D014357:Trypsin; D012083:Renin; D012504:Saralasin