title: Roles of intracellular cyclic AMP signal transduction in the capacitation and subsequent hyperactivation of mouse and boar spermatozoa.
abstract: It is not until accomplishment of a variety of molecular changes during the transit through the female reproductive tract that mammalian spermatozoa are capable of exhibiting highly activated motility with asymmetric whiplash beating of the flagella (hyperactivation) and undergoing acrosomal exocytosis in the head (acrosome reaction). These molecular changes of the spermatozoa are collectively termed capacitation and promoted by bicarbonate, calcium and cholesterol acceptors. Such capacitation-promoting factors can stimulate intracellular cyclic AMP (cAMP) signal transduction in the spermatozoa. Meanwhile, hyperactivation and the acrosome reaction are essential to sperm fertilization with oocytes and are apparently triggered by a sufficient increase of intracellular Ca²⁺ in the sperm flagellum and head, respectively. Thus, it is necessary to investigate the relationship between cAMP signal transduction and calcium signaling cascades in the spermatozoa for the purpose of understanding the molecular basis of capacitation. In this review, I cover updated insights regarding intracellular cAMP signal transduction, the acrosome reaction and flagellar motility in mammalian spermatozoa and then account for possible roles of intracellular cAMP signal transduction in the capacitation and subsequent hyperactivation of mouse and boar spermatozoa.
authors.affiliation: Laboratory of Reproductive Biology, Graduate School of Agricultural Science, Kobe University, Kobe 657-8501, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Harayama
mesh_terms: D020101:Acrosome Reaction; D000818:Animals; D020013:Calcium Signaling; D000242:Cyclic AMP / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D008954:Models, Biological; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D015290:Second Messenger Systems; D013045:Species Specificity; D013075:Sperm Capacitation; D032961:Sperm Midpiece / Q000378:metabolism; D013081:Sperm Motility; D013082:Sperm Tail / Q000378:metabolism; D013084:Sperm-Ovum Interactions; D013094:Spermatozoa / Q000378:metabolism*; D034421:Sus scrofa
chemical_list: D000242:Cyclic AMP