The Effects of Anordrin on Luteal Cells, DecidualCellsand TrophoblastCells in Vitro

Division of Reproductive Pharmacology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 200031, China *DEPT. Of Pharmacology, Shanghai Tiedao University, Medical College Shanghai 200070, China By using the morphology and the viability of cells index, the direct effects of anordrin on serum free primary cultures of rat luteal cells, human decidual cells and trophoblast cells were observed.Meanwhile, the effect of anordrin on the secretive function of rat luteal cells was also observed. The results indicated that (1) anordrin has damaging effects on rat luteal cells, human decidual cells and trophoblast cells. The LD 50 s were 14.34±0.9 μg/ml, 17.33±4.1 μg/ml and 34.87±4.9 μg/ml respectively. (2) With nonlethal dose (5 μg/ml), the activity of progesterone secretion of rat lutein cells which was stimulated by hCG and pregnenolone was not influenced by anordrin while the stimulating activity of forskolin was inhibited remarkably.The results suggest that luteolytic action is the main mechanism of the termination of early pregnancy by anordrin and the direct damaging effects of anordrin on decidua and cytotrophoblasts also play a role in the termination of early pregnancy.

Effect of Metformin-Induced Stimulation on the Expression of Insulin Receptor Substrate 1 through Negative Regulation of P70S6k

Objective:The aim is to study the effects of metformin on the expression of 70 kDa ribosomal protein S6 kinase(P70S6k),insulin receptor substrate 1(IRS-1),and IRS-1Ser307 phosphorylation in human luteinized granulosa cells.Methods:Granulosa cells in the experimental group were cultured in M199 medium containing 0.1 mmol/L metformin for 24 h and those in control group were cultured in M199 medium.The expression levels of P70S6k and IRS-1 mRNA were detected by reverse-transcriptiom polymerase chain reaction(RT-PCR)and real-time PCR.P70S6k,IRS-1,p-ser307-IRS-1,and p-thr389-P70S6k protein expression levels were detected by immunofluorescence and western blotting.Results:P70S6k mRNA level was higher and IRS-1 was significantly lower in the experimental group than those in the control group.IRS-1 and p-ser307-IRS-1 were expressed in cell plasma,and P70S6k and p-thr389-P70S6k were expressed in cell nucleus.The results of Western blot analysis indicated that the expression levels of P70S6k,p-thr389-P70S6k,IRS-1,and p-ser307-IRS-1 proteins had significant difference between the experimental group and the control group.Compared to the control group,the relative intensity illustrated that the expression levels of P70S6K and p-thr389-P70S6k significantly increased in the experimental group;however,those of IRS-1 and p-ser307-IRS-1 proteins significantly decreased.Conclusion:Metformin can inhibit the P70S6k mRNA and protein expression levels in the granulosa cells and improve insulin sensitivity by regulating IRS-1 expression through Akt/P70S6k/IRS-1-dependent pathway.