title: Effect of captopril and aprotinin on inactive renin.
abstract: Inactive renin (prorenin) was measured in plasma from untreated hypertensive patients after acute (60 min) administration of the angiotensin I converting enzyme inhibitor captopril, after 4 weeks of treatment with captopril, and after an acute infusion of the protease inhibitor aprotinin. Inactive renin was unchanged during acute captopril therapy despite a 4-fold increase in active renin. In contrast, after 4 weeks of treatment with captopril, inactive renin had increased 2-fold and active renin was also elevated, but to a greater degree (6-fold). Active renin was significantly suppressed by the aprotinin infusion, to about 25%, but the inactive plasma renin level was apparently unchanged. These studies demonstrate that the time course of the responses of active and inactive plasma renins are different; the inactive renin level seems to change more slowly than does active renin in response to the same stimulus. The results also show that a neutral serine protease inhibitor can rapidly reduce the circulating level of active renin. This observation is consistent with the possibility, but does not prove it, that a kallikrein-like enzyme normally activating prorenin was inhibited by aprotinin.
mesh_terms: D007611:Aprotinin / Q000008:administration & dosage / Q000627:therapeutic use*; D002216:Captopril / Q000008:administration & dosage / Q000627:therapeutic use*; D003080:Cold Temperature; D004334:Drug Administration Schedule; D004792:Enzyme Precursors / Q000097:blood; D006801:Humans; D006973:Hypertension / Q000097:blood* / Q000188:drug therapy; D011392:Proline / Q000031:analogs & derivatives*; D012083:Renin / Q000097:blood*
chemical_list: D004792:Enzyme Precursors; D007611:Aprotinin; D011392:Proline; D002216:Captopril; D012083:Renin