Effects of Glycidamide on Activity and Progesterone Biosynthesis of Rat R2C Leydig Cells

Objective] This study aimed to investigate the effects of glycidamide （GA） on growth and progesterone biosynthesis of rat R2C Leydig cel s cultured in vitro. [Method] The R2C Leydig cel s were treated with GA with concentrations of 0.25, 0.5, 0.75, 1, 2, 4 and 6 mmol/L respectively for 48 h. The IC25, IC50 and IC75 values of GA were al detected by MTT assay. The Leydig cel s were treated with GA at concentrations of IC25, IC50 and IC75 respectively for 48 h, and then the morphology of Leydig cel s was observed. After the Leydig cel s were treated with GA for 4 h, the cel ular DNA damage was measured by the comet assay technique; and after the Leydig cel s were with treated with GA for 24 h, the progesterone biosynthesis amount was detected by radioimmunoassay （RIA）. [Result] GA could inhibit the via-bility of R2C Leydig cel s, and its IC25, IC50 and IC75 were 0.635, 0.872 and 1.198 mmol/L, respectively. The GA at concentrations of IC25, IC50 and IC75 affected the growth and morphology of rat R2C Leydig cel s in varying degrees. The 4-h treat-ment of GA could significantly damage the DNA of R2C Leydig cel s, and the 24-h treatment of GA at concentrations of IC25, IC50 and IC75 al reduced the progesterone biosynthesis amount. [Conclusion] GA could inhibit the growth and progesterone biosynthesis of rat R2C Leydig cel s.

Factors influencing success rate of IVF/ET:analysis of 770 treatment cycles

Objective:To evaluate the factors influencing success rate of in vitro fertilization/embryo transfer(IVF/ET).Methods:A retrospective study of 770 consecutive cycles undergone IVF/ET or in-tracytoplasmic sperm injection(ICSI)from March 1999 to June 2001.Estradiol and pro-gesterone concentrations on the day of hCG administration were measured.Factors effecting embryo transfer on the effects of clinical pregnancy rate were evaluated.Results:The overall clinical pregnancy rate in 770 cycles was 40.8%.Take home baby rate was 31%.No significantly differences rate were observed between groups with different estradiol levels.If the progesterone concentration on the day of hCG ad-ministration was>6.36 nmol/L,the implantation and clinical pregnancy rate was lower(P<0.003).The lowest clinical pregnancy rate was observed when the duration of in-fertility was≥10 years.The average number of embryos transferred was 2.23±0.83.Conclusion:This study demonstrated that the most important factor on clinical pregnancy rate was low progesterone concentration on the day of hCG administration.The other two important variables influencing success rate of IVF/ET were the duration of infertility,the number of high-grade embryos transferred.