title: Effect of protease inhibitors on angiotensin-converting enzyme activity in human T-lymphocytes.
abstract: The purpose of these investigations was to determine whether the aminopeptidase B and leucine aminopeptidase inhibitor bestatin, the chymase inhibitor chymostatin, the calpain inhibitor E-64, and the neutral serine protease inhibitor leupeptin affect the angiotensin converting enzyme (ACE) activity in T-lymphocytes. ACE activity in homogenates of T-lymphocytes or in intact T-lymphocytes in suspension was measured by determining fluorimetrically histidyl-leucine, formed from the conversion of hippuryl-histidyl-leucine, coupled with ophtaldialdehyde. The effect of various concentrations (10(-9) to 10(-3) mol/L) of the angiotensin-converting enzyme inhibitors lisinopril and captopril and of the various protease inhibitors on ACE activity was studied. Lisinopril and captopril reduced the ACE activity in homogenates of T-lymphocytes in a concentration-dependent manner. Lisinopril exhibited a more pronounced inhibition of ACE in T-lymphocytes than did captopril. Chymostatin and E-64 had no effect on the ACE activity in T-lymphocytes, whereas leupeptin inhibited its activity in a dose-dependent fashion. Bestatin, on the contrary, increased the ACE activity in homogenates of T-lymphocytes as well as in intact T-lymphocytes in proportion to the concentration. Our data showed that the ACE activity in T-lymphocytes was stimulated by bestatin and inhibited by leupeptin, whereas chymostatin and E-64 did not affect the ACE activity in T-lymphocytes.
authors.affiliation: Department of Molecular and Cardiovascular Research, KULeuven, Belgium.
authors.forename: V
authors.initials: V
authors.lastname: Petrov
authors.forename: R
authors.initials: R
authors.lastname: Fagard
authors.forename: P
authors.initials: P
authors.lastname: Lijnen
mesh_terms: D000328:Adult; D000626:Aminopeptidases / Q000037:antagonists & inhibitors; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology; D002154:Calpain / Q000037:antagonists & inhibitors; D002216:Captopril / Q000494:pharmacology; D002403:Cathepsins / Q000037:antagonists & inhibitors; D002918:Chymotrypsin / Q000037:antagonists & inhibitors; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D006801:Humans; D007930:Leucine / Q000031:analogs & derivatives / Q000494:pharmacology; D007976:Leupeptins / Q000494:pharmacology; D017706:Lisinopril / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects / Q000502:physiology; D008297:Male; D009842:Oligopeptides / Q000494:pharmacology; D007703:Peptidyl-Dipeptidase A / Q000378:metabolism*; D011480:Protease Inhibitors / Q000494:pharmacology*; D013601:T-Lymphocytes / Q000187:drug effects* / Q000201:enzymology
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D015853:Cysteine Proteinase Inhibitors; D007976:Leupeptins; D009842:Oligopeptides; D011480:Protease Inhibitors; C002101:chymostatin; D002216:Captopril; D017706:Lisinopril; D002403:Cathepsins; D000626:Aminopeptidases; C019721:aminopeptidase B; D007703:Peptidyl-Dipeptidase A; D002918:Chymotrypsin; D002154:Calpain; D007930:Leucine; C012211:ubenimex; C032854:leupeptin; C024974:E 64