Ramipril inhibition of rabbit (Oryctolagus cuniculus) small intestinal brush border membrane angiotensin converting enzyme.
1. Rabbit small intestinal brush border membranes possessed prominent angiotensin converting enzyme (ACE) activity. 2. Intestinal ACE was located on the lumen surface, as verified by ACE co-enrichment with brush border membrane marker enzymes. 3. Hydrolysis kinetics of rabbit intestinal ACE were comparable to the lung, utilizing the substrate (N-[3-(2-furyl)acryloyl]-L-phenylalanylglycylglycine; the Vmax = 543 +/- 51 mumol/min/g and Km = 0.62 +/- 0.09 mmol/l. 4. Intestinal brush border ACE activity was strongly inhibited by the antihypertensive drug Ramipril, which yielded an IC50 value of 5 nmol/l; the ACE activity remained completely inhibited during 15 days after a single dose of 10 mumol/l Ramipril.
Stevens
B R
BR
Department of Physiology, College of Medicine, University of Florida, Gainesville 32610.
Phillips
M I
MI
Fernandez
A
A
D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology*; D000818:Animals; D001643:Bridged Bicyclo Compounds / Q000494:pharmacology*; D001952:Bridged-Ring Compounds / Q000494:pharmacology*; D006868:Hydrolysis; D007421:Intestine, Small / Q000187:drug effects* / Q000201:enzymology / Q000648:ultrastructure; D007700:Kinetics; D008871:Microvilli / Q000187:drug effects / Q000378:metabolism; D011817:Rabbits; D017257:Ramipril
D000806:Angiotensin-Converting Enzyme Inhibitors; D001643:Bridged Bicyclo Compounds; D001952:Bridged-Ring Compounds; D017257:Ramipril