A possible mechanism of action for fertilization promoting peptide, a TRH-related tripeptide that promotes capacitation and fertilizing ability in mammalian spermatozoa

Peptidase activities in Crotalus durissus terrificus semen

“…Many peptides, such as angiotensins (Angs; Fraser et al 2006), kinins (Blaukat 2003), substance P, enkephalins (Sastry et al 1991), endorphin (El-Haggar et al 2006), oxytocin (OXT), vasopressin (AVP; Assinder et al 2000), LHRH (Amory & Bremner 2003), TRH, and fertilization-promoting peptide (FPP; Green et al 1996), as well some peptidases, particularly aminopeptidases (APs) and oligopeptidases have been related to seminal physiology in mammals (Fernández et al 2002, Subirán et al 2008. In this sense, Ang I and II are hydrolyzed by acid AP (APA; EC 3.…”

Mechanisms of action of angiotensin II on mammalian sperm function

“…Ca 2þ -deficient Tyrode's medium, with no added CaCl 2 , contains trace amounts of approximately 13 mM Ca 2þ (Fraser 1982), insufficient to support capacitation in most species. Mouse spermatozoa must have at least 90 mM CaCl 2 in order to undergo complete capacitation, while optimal fertilizing ability requires 1.80 mM CaCl 2 (Fraser 1987 (Green et al 1996). It therefore seemed reasonable to determine whether biological responses to AII required the presence of added Ca 2þ .…”

Production of Piglets Derived from In Vitro-Produced Blastocysts Fertilized and Cultured in Chemically Defined Media: Effects of Theophylline, Adenosine, and Cysteine During In Vitro Fertilization1

“…A recent study using a chlortetracycline fluorescence assay has shown that caffeine stimulates both capacitation and spontaneous acrosome reaction of ejaculated boar spermatozoa, whereas adenosine promotes capacitation and inhibits spontaneous acrosome reaction, regardless of the presence or absence of caffeine [27,28]. In mouse spermatozoa, adenosine modulates the adenylyl cyclase/cAMP pathway [29,30] and induces sperm response via adenosine A 2 receptors in uncapacitated cells and through adenosine A 1 receptors in capacitated cells [31,32]. In boar spermatozoa, adenosine appears to act via mechanisms similar to those observed in mice [8,26].…”