大豆黄酮对体外灌流垂体前叶组织促黄体素分泌的影响

EFFECT OF DAIDZEIN ON LH SECRETION IN THE SUPERFUSION SYSTEM OF ANTERIOR PITUITARY TISSUE FROM GOETTINGEN MINIATURE GILTS

对德国格丁根微型猪垂体前叶组织进行体外灌流培养，研究大豆黄酮对垂体促黄体素（ＬＨ）分泌的影响。结果表明，灌流２４ｈ后，大豆黄酮灌流组（Ⅰ组１００ｎｇ／ｍｌ；Ⅱ组２μｇ／ｍｌ）和雌二醇灌流组（Ⅲ组１００ｐｍｏｌ／Ｌ；Ⅳ组２００ｐｍｏｌ／Ｌ）ＬＨ分泌水平低于对照组（Ⅴ组空白对照；Ⅵ组助溶剂对照），雌激素抑制效应明显较强。灌流４８ｈ，Ⅰ、Ⅱ组ＬＨ峰值和平均水平均显著高于对照组，Ⅲ、Ⅳ组则明显低于对照组。促性腺激素释放激素（ＧｎＲＨ）刺激后１～２ｈ，Ⅰ、Ⅱ组ＬＨ平均水平、峰值和脉冲频率均明显高于刺激前，而且显著高于对照组；Ⅲ、Ⅳ组却明显低于对照组和Ⅰ、Ⅱ组。大豆黄酮、雌激素对垂体体外ＬＨ分泌没有明显的剂量差异。无ＧｎＲＨ刺激时，大豆黄酮对离体垂体ＬＨ分泌表现为抑制效应，但抑制强度较弱；长期以大豆黄酮灌流培养垂体，或加以ＧｎＲＨ刺激，大豆黄酮对ＬＨ分泌具促进作用。

This study was conducted to examine the effect of daidzein(Da) on the secretion of luteinizing hormone (LH) in vitro by the pituitaries of Goettingen Miniature gilts in superfusion system. The pituitaries were cultured in Da solution (group Ⅰ, containing 100 ng/ml group; Ⅱ, 2 μg/ml), estradiol benzoate (BE) (group Ⅲ, 100 pmol/L; group Ⅳ, 200 pmol/L), normal cultural medium (group Ⅴ) and medium, containing equivalent contents of solvents of daidzein (group Ⅵ). The samples were collected at 24 h after superfusion. The results showed that LH levels were significantly lower in group ⅠⅣ than in the control (Ⅴ,Ⅵ), but group Ⅰ and Ⅱ had weaker inhibition ability than group Ⅲ and Ⅳ. At 48 h after superfusion, group Ⅰ and Ⅱ exhibited higher peak and average levels of LH, but group Ⅲ and Ⅳ had lower level secretion of LH than the controls. For 1 to 2 hours after GnRH treated, basal level, peak and pulsatile frequence of LH in group Ⅰ and Ⅱ were significantly higher than those before GnRH, and also higher than in the controls. However, they were lower in group Ⅲ and Ⅳ than in the controls and group Ⅰ and Ⅱ. Da and BE had no significant differences in LH secretion at different dosages. These results suggested that Da had the same inhibition effect as estrogen on LH secretion in the superfusion system if without stimulation of GnRH and cultivation for short time. But, Da also had antiestrogenic effect on LH in vitro secretion when the pituitaries were cultured with Da for longer time and if GnRH stimulation were applicated.