摘要
为了研究睾酮的自分泌调节机制,选取2-3周龄的仔猪睾丸间质细胞为研究材料。不同浓度的睾酮(0、10mg/mL、20mg/mL、50mg/mL、100mg/mL)与间质细胞共孵育48h,更换培养液,加入hCG(50U/mL)孵育4h,收集培养液,用放射免疫法(RIA)测定睾酮、hCG和cAMP的浓度。然后用浓度为50mg/mL的睾酮与胆固醇,5mg/mL;孕烯醇酮,500ng/mL;脱氢表雄酮,500ng/mL;雄烯二酮,500ng/mL和22R-羟胆固醇(3μg/mL)共同孵育间质细胞48h,更换培养液,加入hCG(50U/mL)孵育4h,收集培养液和细胞,用放射免疫法(RIA)测定睾酮,用免疫印迹测定StAR水平。实验结果如下:(1)随着睾酮浓度的增加,睾酮对自身合成的抑制作用逐渐增强,当睾酮浓度为50mg/mL,睾酮分泌、hCG的结合率以及间质细胞内cAMP的浓度分别下降了69.93%、61.24%和52.4%。(2)尽管睾酮抑制了胆固醇和雄烯二酮向睾酮的转化,但对其它几种前体物的转化没有明显影响。(3)睾酮不但抑制了基础水平StAR的表达,而且也抑制了hCG刺激的StAR蛋白的表达,这表明睾酮可以通过抑制StAR蛋白的表达降低自身的合成。
In order to study the autocrine mechanism of testosterone synthesis, Leydig cells from 2-3 week old piglets were used as material. Difference doses of testosterone (0, 10 mg/mL, 20 mg/mL, 50 mg/mL,100 mg/mL) was added into these cultivating bottles and cocultivated with Leydig cells for 48 h. Then, changing cultivating Liquid and certain concentrations of hCG were added to each bottle and go on cultivating up to 4 h. On the other hand, some precursors including cholesterol(5 mg/mL), pregnenolone (500 ng/mL), dehydroepiandrosterone (500 ng/mL), androstenedione (500ng/ml) and 22R-hydroxychol-esterol (3μg/mL) and testosterone(50 mg/mL) were added into these cultivating bottles and cocultivated with leydig cells for 48 h. Then,changing cultivating Liquid and certain concentrations of hCG were added to each bottle and go on cultivating up to 4 h. The concentrations of testosterone, hCG and cAMP were measured by radioimmunoassay, but the level of steroidogenic acute regulatory(StAR) protein was measured by immunoblotting. The results were as follows: (1) with the increase of concentration of testosterone, the inhibiting effect of testosterone was gradually increasing. when the concentration of testosterone was 50 mg/mL, the inhibiting effect is the maximum. The decreasing percentages of concentration of testosterone, hCG binding rate and concentration of cAMP were 69. 93% ,61. 24% and 52. 4%;(2) although the conversion from cholesterol to testosterone,androstenedione to testosterone could significantly be inhibited, the conversion from other precursors to testosterone were not affected significantly; (3) the levels of protein was decreased by testosterone in 4 h. The results showed that testosterone may inhibit its synthesis by decreasing the expressing of StAR protein.
出处
《科学技术与工程》
2005年第9期547-551,共5页
Science Technology and Engineering
基金
国家自然科学基金(30270955)教育部重点科学技术项目重庆市教委项目(01106)资助
关键词
睾酮
间质细胞
类固醇合成快速调节蛋白(StAR)
testosterone human chorionic gonadotrophinn(hCG) Leydig cell steroidogenic a-cute regulatory protein(StAR)
