Cathepsin b inhibitor improves the developmental competence of In vitro grown metabolic stressed ovine oocytes

To investigate the effect of cathepsin B inhibitor (E-64) on the developmental competence of in vitro grown metabolic stressed ovine oocytes (harvested fromabattoir-derived ovaries) good quality oocytes were maturated at 38.5°C for 24 h under control and metabolic stressed [ammonia (250 μM) + urea (8 mM) or non-esterified fatty acid (NEFA,140 μM), beta-hydroxybutyric acid (BHB, 0.7 μM)] conditions. It was observed that treatment of metabolic stressed oocytes with a cathepsin B inhibitor (E-64) at 1.5 mM concentration resulted in significant (P<0.05) improvement in cleavage and blastocyst rate of oocytes with increased (P<0.05) in embryo production. However, further study is needed to clarify the specific underlying mechanisms of effects caused by E-64.