title: Characterization and activity of angiotensin-converting enzyme in Holstein semen.
abstract: The study was designed to perform immunodetection in spermatozoa and seminal plasma, immunolocalization in spermatozoa, and evaluation of the enzymatic activity of angiotensin-converting enzyme (ACE) in the semen of Holstein bulls. We used ejaculates from five bulls as part of a regular collection of semen. The monoclonal anti-ACE antibody recognized a single protein band with 100 kDa in detergent extract prepared from sperm and in seminal plasma. ACE enzymatic activity in sperm was 43.7, 21.3, 45.6, 60.0, and 57.7 mU/mL in bulls 1, 2, 3, 4, and 5, respectively, and 0.3, 2.3, 3.0, 2.3, and 2.6 mU/mL in seminal plasma of the same bulls, respectively. The average percentages of sperm with acrosome reactions after treatment with heparin were 28.3%, 28.6%, 35.2%, 25.0%, and 32.3%, respectively. These values were higher than the percentages of acrosome reactions in controls and the captopril group (P<0.05), although no difference was seen between the captopril and control groups (P>0.05). After 4h of incubation, motility in the control group (32.9%) was significantly higher than that in the heparin (15.7%) and captopril (12.1%) groups. No difference was found in motility after the capacitation assay in the heparin and captopril groups (P>0.05). In conclusion, ACE was immunologically localized in the acrosome of the spermatozoa of Holstein bull, the specific enzymatic activity of ACE in detergent-extracted spermatozoa and seminal plasma was inhibited by captopril, and this ACE inhibitor reduced the percentage of sperm with progressive motility and acrosome reactions after capacitation in vitro.
authors: Federal University of Mato Grosso do Sul, Lab of Assisted Reproduction-FAMEZ, Bolsista da CAPES, Campo Grande, MS, Brazil. deilercosta@yahoo.com.br
authors: Deiler S
authors: DS
authors: Costa
authors: Jacob C
authors: JC
authors: Thundathil
mesh_terms: D020101:Acrosome Reaction / Q000187:drug effects; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology; D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D002216:Captopril / Q000494:pharmacology; D002417:Cattle / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D008297:Male; D007703:Peptidyl-Dipeptidase A / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism* / Q000502:physiology*; D012661:Semen / Q000737:chemistry / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D055101:Semen Analysis; D013075:Sperm Capacitation / Q000187:drug effects; D013081:Sperm Motility / Q000187:drug effects
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D000906:Antibodies; D002216:Captopril; D007703:Peptidyl-Dipeptidase A