title: Atrial natriuretic peptide induces acrosomal exocytosis in bovine spermatozoa.
abstract: The induction of acrosomal exocytosis in capacitated bull spermatozoa by atrial natriuretic peptide (ANP) was studied in vitro. ANP markedly stimulated acrosomal exocytosis in a calcium-dependent manner. Typically, ANP exerts its action via activation of the ANP receptor (ANPR-A), a particulate guanylyl cyclase-linked receptor, and subsequent formation of guanosine 3',5'-cyclic monophosphate (cGMP). We found that the ANP-induced acrosome reaction was inhibited by the competitive ANPR-A receptor antagonist-anantin, indicating a receptor-mediated effect. We could mimic the effect of ANP on the acrosome reaction by using 8-bromo-cGMP, suggesting that cGMP may serve as a signal transducer mediating the acrosome reaction. Indeed, the ANP-induced acrosome reaction was associated with elevation of cGMP levels. cGMP can also be formed by activation of the soluble form of guanylyl cyclase. Sodium nitroprusside (SNP) stimulated cGMP accumulation and acrosome reaction of capacitated spermatozoa. Thus ANP and the nitric oxide-releasing compound SNP, via activation of guanylyl cyclase (the former activating the particulate and the latter activating the soluble form of the enzyme), may play a significant role in the induction of the acrosome reaction.
authors.affiliation: Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Israel.
authors.forename: N
authors.initials: N
authors.lastname: Zamir
authors.forename: D
authors.initials: D
authors.lastname: Barkan
authors.forename: N
authors.initials: N
authors.lastname: Keynan
authors.forename: Z
authors.initials: Z
authors.lastname: Naor
authors.forename: H
authors.initials: H
authors.lastname: Breitbart
mesh_terms: D000177:Acrosome / Q000502:physiology*; D000595:Amino Acid Sequence; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000737:chemistry / Q000494:pharmacology*; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000502:physiology; D002417:Cattle; D006152:Cyclic GMP / Q000378:metabolism; D005089:Exocytosis / Q000502:physiology; D005260:Female; D006162:Guanylate Cyclase / Q000378:metabolism; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D051381:Rats; D017461:Receptors, Atrial Natriuretic Factor / Q000502:physiology; D013084:Sperm-Ovum Interactions / Q000187:drug effects; D013094:Spermatozoa / Q000187:drug effects* / Q000502:physiology*; D013552:Swine
chemical_list: D000001:Calcimycin; D009320:Atrial Natriuretic Factor; D006162:Guanylate Cyclase; D017461:Receptors, Atrial Natriuretic Factor; D006152:Cyclic GMP; D002118:Calcium