PSIV-B-40 Late-Breaking: Effects of Total Flavonoids of Astragaluson on Development, ROS Level and Antioxidant Enzyme Genes Expression in Oxidative Damage Mouse Embryos

In this study, the effect of total flavonoids of astragalus (TFA) on the development, ROS level and the expression of antioxidant enzyme genes in Kunming mouse during in-vitro culture. In the first experiment, effect of different concentration (0 mg/L, 25 mg/L, 50 mg/L, 75 mg/L and 100 mg/L) of TFA was used to determine optimal dose rate. In subsequent experiments, embryos were divided into three groups control, H2O2 treated and optimal concentration TFA+H2O2 treated groups. Our result shows that the 4th cell and blastocyst rate was significantly higher in 75 mg/L TFA group (P < 0.05) than the other groups. The intracellular ROS level was significantly higher in H2O2 group (P < 0.05) which was significantly decrease after the supplementation of TFA. Moreover the mRNA expression level of SOD1 and SOD2 in the TFA+H2O2 group were significantly higher than the H2O2 group (P < 0.05); however, the mRNA expression level of CAT, GPx1 and GPx4 were significantly higher in TFA+H2O2 group compared to H2O2 group (P < 0.01). In conclusion, the present shows that the optimal dose rate of TFA in vitro embryo culture was 75 mg/L. TFA treatment can reduce ROS level, improve the expression levels of CAT, SOD1, SOD2, GPx1 and GPx4 in blastocyst of mice in oxidative stress condition

Rapid Dissociation of Cortical Neurons from Neonate Rats and Patch-Clamp Recording

In order to get the single cortical neurons fitting the study of patch-clamp technique.use the kunming mouse with the birth of 10 days or so, and separate neurons in the cerebral cortex through acute separation technology and enzymatic hydrolysis. A cone-shaped adherent neurons are selected and observed in rapid dissociation and cell activity status under the inverted microscope. Different ion channel blockers is added to the extracellular fluid and used whole-cell recording which can obtain Na +, K + and other ion channel currents. This method can obtain good morphological and physiological characteristics of both single cortical neurons, confirming that the method applied to cortical neurons by patch clamp technique, which has significant value for in-depth research on drugs, toxins and other physical factors on the electrical activity of neuronal ion channels and signal transduction mechanism of the effect.

The Kunming mouse: as a model for age-related decline in female fertility in human

SummaryTo ascertain whether the Kunming (KM) mouse is an available model for age-related decline in female fertility in human or not, oocytes from young (6–8 weeks), middle-aged (9 months) and aged (12 months) female mice were compared with respect to number of oocytes, frequency of in-vitro maturation (IVM) and in-vitro fertilization (IVF), and meiotic chromosome segregation and alignment. The mean number of pups born per mouse decreased significantly from the young to the middle-aged and the aged mice. The mean number of ovarian follicles, ovarian germinal vesicle oocytes and ovulated MII oocytes decreased significantly with maternal age. The rate of IVM in oocytes from young mice (73.9%) was less significantly than that in oocytes from middle-aged and aged mice (86.1% and 84.4%, respectively). Immunocytochemical analysis showed that ageing caused a significantly higher rate (49.3%) of chromosome misalignment than that (15.7%) of the young mice. The presence of premature chromatids was also significantly higher in MII oocytes of aged mice as compared with young mice (37.8 versus 8.3%). Pronuclear formation was delayed in oocytes of middle-aged and aged females (35.5 and 42.3% respectively in 5 h of IVF) as compared with young mice (88.1%). The study suggests that KM mouse exhibits an age-related decline in female fertility. Significant reduction of germinal vesicle (GV) and MII oocytes and significant increase of metaphase chromosome misalignment and premature chromatid segregation after meiotic maturation of oocytes, similar to human, presumably contribute to the decline in aged KM mice.