Hunter M G, Sullivan M H, Dix C J, Aldred L F, Cooke B A
Mol Cell Endocrinol. 1982 Jun;27(1):31-44. doi: 10.1016/0303-7207(82)90060-0.
The effect of 2 luteinizing hormone-releasing hormone (LHRH) analogues(10-8-10-6 M) on the functional activity (testosterone and cyclic AMP production and [125I]hCG binding) of purified mouse Leydig cells in culture was examined. The analogues were found to have no significant effect on the cells over a period of 3 days. No specific binding of a labelled analogue to impure or pure mouse Leydig cells could be detected. In contrast high levels of specific binding to impure rat interstitial cells occurred. Centrifugation of the rat interstitial cells on 0-90% Percoll gradients showed that the LHRH analogue bound specifically to the active lutropin-responsive Leydig cells. The purified rat Leydig cells were cultured in the presence of LHRH analogue (ICI 118630) (10-7 M) and after an initial lag period (2h) a marked stimulation of testosterone production occurred over a 32-h period (up to 400 ng/10(6) cells). The response to LH alone increased with time in culture up to 10 h, and the LHRH analogue enhanced this LH-stimulated testosterone production. When the cells were cultured for longer time periods (24 h) the LHRH analogue was found to inhibit LH-stimulated testosterone production at all concentrations of LH used (p less than 0.01). The LHRH analogue had no consistent effect on LH-stimulated cyclic AMP production, although when added alone, cyclic AMP production was increased. These results show that LHRH analogues do not bind to or have any detectable effect on mouse Leydig cells in vitro. However, LHRH analogue does bind specifically to purified rat Leydig cells. After a short lag period the analogue stimulates testosterone production which turns to inhibition after 20 h in culture.
研究了两种促黄体生成激素释放激素（LHRH）类似物（10⁻⁸ - 10⁻⁶ M）对培养的纯化小鼠睾丸间质细胞功能活性（睾酮和环磷酸腺苷生成以及[¹²⁵I]人绒毛膜促性腺激素结合）的影响。发现这些类似物在3天内对细胞无显著影响。未检测到标记类似物与不纯或纯的小鼠睾丸间质细胞有特异性结合。相反，与不纯的大鼠间质细胞发生了高水平的特异性结合。在0 - 90%的 Percoll 梯度上对大鼠间质细胞进行离心，结果显示 LHRH 类似物特异性结合到有活性的促黄体激素反应性睾丸间质细胞上。纯化的大鼠睾丸间质细胞在 LHRH 类似物（ICI 118630）（10⁻⁷ M）存在的情况下培养，经过初始延迟期（2小时）后，在32小时内睾酮生成显著增加（高达400 ng/10⁶ 个细胞）。单独对促黄体激素（LH）的反应在培养至10小时时随时间增加，并且 LHRH 类似物增强了这种 LH 刺激的睾酮生成。当细胞培养更长时间（24小时）时，发现 LHRH 类似物在所用的所有 LH 浓度下均抑制 LH 刺激的睾酮生成（p < 0.01）。LHRH 类似物对 LH 刺激的环磷酸腺苷生成没有一致的影响，尽管单独添加时环磷酸腺苷生成增加。这些结果表明，LHRH 类似物在体外不与小鼠睾丸间质细胞结合或对其有任何可检测到的影响。然而，LHRH 类似物确实特异性结合到纯化的大鼠睾丸间质细胞上。经过短暂的延迟期后，该类似物刺激睾酮生成，在培养20小时后转变为抑制作用。
