紫草多糖对hCG诱导大鼠黄体细胞分泌功能的影响

采用体外黄体细胞培养,观察中药紫草的水溶成分——紫草多糖对hCG诱导的黄体细胞分泌孕酮影响,并探讨其可能机制。选取未成年雌性SD大鼠,分离黄体细胞,分为基础组和hCG组,分别添加不同浓度紫草多糖,放射免疫检测各组细胞内和培养液中的孕酮(Progesterone,P4)含量;将细胞悬液分为4组:空白对照组、1.50g.L-1紫草多糖组、2×104 U/L hCG组以及hCG(2×104 U/L)+紫草多糖(1.50g.L-1)组,在培养的不同时间点(0、0.5、1、2h时),分别测P4产量,观察紫草多糖对培养黄体细胞作用的起效时间和动力学变化。此外,上述4组培养0.5h后离心分离细胞和培养液,分别测得细胞内和培养液中的cAMP和cGMP含量,将细胞内和培养液中的含量之和作为总量,并计算其cAMP/cGMP比值。结果表明:1.紫草多糖呈剂量依赖性地抑制hCG刺激下黄体细胞P4的生成。2.加大剂量(>3.00g.L-1)紫草多糖亦可抑制基础P4的生成。3.1.50g.L-1紫草多糖组从作用0.5h起,即显著抑制黄体细胞hCG刺激下的P4生成(P<0.01)。4.hCG可明显增加黄体细胞cAMP含量,导致cAMP/cGMP增加。添加1.50g.L-1紫草多糖可增加cAMP、cGMP含量,但cAMP/cGMP比值下降。结论:紫草多糖可直接作用于促性腺激素的靶细胞——黄体细胞,并抑制hCG诱导黄体细胞分泌功能,该抑制作用起效快,并可能通过cGMP介导。

Effects of lithosperman on the secretory function induced by hCG in rats' luteal cells

The effects of the water-soluble ingredients of lithospermum-lithosperman,on progesterone secretion induced by hCG in rat luteal cells Utilizing the in vitro cultured luteal cells was studied,through the in vitro cultured luteal cells.The related mechanisms were investigated,too.The Luteal cells were isolated from immature female SD rats selected and divided into control and hCG group.Different concentrations of lithosperman were added into each group.Afterwards,the contents of both intercellular progesterone and the progesterone in culture solution were detected by radioimmunity.In order to reveal the onset time and kinetic features of lithosperman on hCG secretion,the cell suspension was divided into four groups:control group,1.50 g·L-1 lithosperman group,2×104 U/L hCG group and hCG(2×104 U/L)+lithosperman(1.50 g·L-1) group.The contents of progesterone were then examined at different cultured time points(0,0.5,1 or 2 h) in each group.In addition,the cells after 0.5 h culture were centrifuged and separated from the culture solutions.The total cAMP and cGMP were obtained by summing up the contents in cells and solutions,and the cAMP/cGMP ratios was calculated.The results showed:1.Lithosperman suppressed the hcG-induced progesterone production in luteal cells in a dose-dependent manner.2.Lithosperman in high dose(>3.00 g·L-1) could inhibit the basic progesterone generation in the controlled group.3.In the concentration of 1.50 g·L-1 group,lithosperman started to significantly inhibit the hCG-induced progesterone generation after 0.5 h incubation.4.hCG obviously increased the cAMP content in luteal cells,resulting in the elevation of cAMP/cGMP ratio.However,the net effect was that cAMP/cGMP ratio decreased although the addition of 1.50 g·L-1 lithosperman increased the contents of both cAMP and cGMP.Conclusions:Lithosperman could inhibit the hCG-induced hormone secretion in luteal cells,which are the targets of gonadotropins.Furthermore,the quick effect of lithosperman hints that it might be mediated by cGMP.