Effects of Sodium Nitroprusside and Nitric Oxide on In Vitro Maturation of Canine Oocytes

These study was carried out to investigate the effects of the supplementation with sodium nitroprusside (SN) and nitric oxide (NO) of canine oocytes on IVM rates. Oocytes were incubated in TCM-199 supplement with at 0.03~0.10 mM SN and 0.3~1.0 mM NO for 48 hrs. Oocytes were transferred to 50 ul drops of maturation medium covered mineral oil and cultured in a $CO_2$ incubator (5% $CO_2$, 95% air, $38^{\circ}C$). The in vitro maturation rate of oocytes cultured for 48 hrs in TCM-199 medium supplement with 0.03, 0.05, 0.07, 0.10 mM SN were $25.9{\pm}3.5%$, $36.4{\pm}3.2%$, $33.3{\pm}3.5%$, $28.8{\m}3.2%$, respectively. The in vitro maturation rate of oocytes cultured for 48 hrs in TCM-199 medium supplement with 0.03~0.07 mM SN were significantly increased compare to the control ($26.0{\pm}2.2%$). The in vitro maturation rates of oocytes cultured for 48 hrs in TCM-199 medium supplement with 0.3, 0.5, 0.7, 1.0 mM NO were $28.0{\pm}4.2%$, $36.5{\pm}3.6%$, $30.0{\pm}3.8%$, $19.2{\pm}3.5%$, respectively. The in vitro maturation rate of oocytes in TCM-199 medium supplemented with 0.3 and 0.5 mM NO were significantly increased compare to the control ($26.0{\pm}2.2%$). The in vitro maturation rates of oocytes cultured for 12~48 hrs in TCM-199 medium supplement with 0.05 mM SN were $26.0{\pm}3.2%$, $28.0{\pm}3.4%$, $38.0{\pm}3.2%$, respectively. The in vitro maturation rate of oocytes cultured for 12~48 hrs in TCM-199 medium supplement with 0.5 mM NO were $22.0{\pm}3.0%$, $30.0{\pm}3.8%$, $36.0{\pm}4.2%$, respectively. These result was significantly increased compare to the control.