Effect of plasmin, plasminogen activators and a plasmin inhibitor on bovine in vitro embryo production

摘要

In the present study, four experiments were conducted to investigate the possible effects of plasminogennactivators (urokinase-type plasminogen activator (u-PA) and tissue-type plasminogen activator (t-PA)), plasmin, and anplasmin inhibitor (epsilon-aminocaproic acid (ε-ACA)) on different stages of bovine in vitro embryo production (IVP).nThe concentrations of these modifiers in IVP media were conditioned according to the plasminogen activator activity ofnbovine preovulatory follicular fluid. Media were modified in a single phase of IVP with an 18 h or 24 h incubation fornin vitro maturation (IVM) and a 24 h or 48 h incubation for the IVF or in vitro culture (IVC), respectively. After IVMnthe oocytes were either fixed and stained or underwent IVF and IVC. The main findings were: (1) plasmin added to then18 h IVM medium increased maturation rate without affecting fertilisation or embryo development rates; (2) t-PA addednto the IVF medium significantly increased cleavage; (3) u-PA added to the IVC medium significantly increased embryondevelopment rates; (4) the efficiency of all phases of IVP was reduced after the addition of ε-ACA; and (5) plasminogennaddition had no effect in any IVP phase tested. We conclude that the members of the plasminogen activator–plasminnsystem contribute in different ways to bovine IVM, IVF and IVC.