The effect of sodium nitroprusside (SNP), a donor of nitric oxide, on meiotic maturation of mouse oo-cytes was studied by injecting Nw-nitro-L-arginine methyl ester (L-NAME) intra-peritoneal (ip), a nitric oxide synth...The effect of sodium nitroprusside (SNP), a donor of nitric oxide, on meiotic maturation of mouse oo-cytes was studied by injecting Nw-nitro-L-arginine methyl ester (L-NAME) intra-peritoneal (ip), a nitric oxide synthase inhibitor, or culturing oocytes in the medium supplemented with L-NAME or hypoxanthine (HX) to arrest the sponta-neous oocyte maturation in vitro. The results showed that the inhibitory effect of L-NAME by injecting 10 mg/kg ip on extrusion of the first polar body only could be reversed by injecting 2.5 mg/kg SNP with L-NAME simultaneously (P < 0.05). Half an hour later ten mice died when given 10 mg/kg SNP ip. The treatment of some concentrations of SNP (10-7,10-6,10-5mol/L) significantly stimulated meiotic matu-ration to metaphase Ⅱ stages in cumulus enclosed oocytes in the presence of HX. However, other concentrations of SNP (10-8, 10-4, 10-3 mol/L) had no effect on HX-arrested oocyte meiotic maturation. The optimal concentration of SNP on CEOs had no effect on DOs. The dose of 10-3 mol/LL-NAME demonstrated a significant suppression in formation of PB1, but not in GVBD. This inhibition was reversed by the addi-tion of SNP. These results indicated that the physiological levels of NO produced by cumulus cells could stimulate mei-otic maturation of mouse oocytes both in vivo and in vitro.展开更多
A sensitive bioassay for estimating the activity of Trichosanthin was developed by using intraoocyte microinjection as the technique and germinal vescicle breakdown as a marker. The GVBD inhibitory activity assay was ...A sensitive bioassay for estimating the activity of Trichosanthin was developed by using intraoocyte microinjection as the technique and germinal vescicle breakdown as a marker. The GVBD inhibitory activity assay was million-fold more sensitive than the routinely used abortifacient activity assay. The detectable amount of Trichosanthin ranged from 0.5 to 100 pg. Since the least detectable dose was 0.5 pg, it made the assay suitable to analyse the microquantity of pure Trichosanthin used for studying the structure and function of the drug.展开更多
基金This work was supported by the National Out-standing Youth Foundation (Grant No. 30025032) and the Natural Sci-ence Foundation of Beijing (Grant No. 6992019).
文摘The effect of sodium nitroprusside (SNP), a donor of nitric oxide, on meiotic maturation of mouse oo-cytes was studied by injecting Nw-nitro-L-arginine methyl ester (L-NAME) intra-peritoneal (ip), a nitric oxide synthase inhibitor, or culturing oocytes in the medium supplemented with L-NAME or hypoxanthine (HX) to arrest the sponta-neous oocyte maturation in vitro. The results showed that the inhibitory effect of L-NAME by injecting 10 mg/kg ip on extrusion of the first polar body only could be reversed by injecting 2.5 mg/kg SNP with L-NAME simultaneously (P < 0.05). Half an hour later ten mice died when given 10 mg/kg SNP ip. The treatment of some concentrations of SNP (10-7,10-6,10-5mol/L) significantly stimulated meiotic matu-ration to metaphase Ⅱ stages in cumulus enclosed oocytes in the presence of HX. However, other concentrations of SNP (10-8, 10-4, 10-3 mol/L) had no effect on HX-arrested oocyte meiotic maturation. The optimal concentration of SNP on CEOs had no effect on DOs. The dose of 10-3 mol/LL-NAME demonstrated a significant suppression in formation of PB1, but not in GVBD. This inhibition was reversed by the addi-tion of SNP. These results indicated that the physiological levels of NO produced by cumulus cells could stimulate mei-otic maturation of mouse oocytes both in vivo and in vitro.
文摘A sensitive bioassay for estimating the activity of Trichosanthin was developed by using intraoocyte microinjection as the technique and germinal vescicle breakdown as a marker. The GVBD inhibitory activity assay was million-fold more sensitive than the routinely used abortifacient activity assay. The detectable amount of Trichosanthin ranged from 0.5 to 100 pg. Since the least detectable dose was 0.5 pg, it made the assay suitable to analyse the microquantity of pure Trichosanthin used for studying the structure and function of the drug.
