Jenner A A, de Koning J, van Rees G P
Life Sci. 1983 Mar 7;32(10):1091-8. doi: 10.1016/0024-3205(83)90114-5.
During long-term incubation of pituitary glands from intact female rats in the presence of inhibin-like activity, LH-RH-stimulated release of FSH becomes inhibited after 4 h of incubation. However, at the same time inhibition of basal FSH release is included. Therefore, glands were at first incubated for 4 h in the presence of inhibin-like activity to block basal release completely and thereafter LH-RH was added to the medium. It was found that LH-RH still could stimulate FSH release, despite the continuous presence of inhibin-like activity. This means that LH-RH-stimulated release of FSH could be investigated separately from basal release. Using this way of incubation, it was found that part of the action of LH-RH on FSH release was independent of protein synthesis. Also part of LH-RH-stimulated FSH release was independent of the presence of extracellular Ca2+. Furthermore it was found that LH-RH, when added after 4 h of incubation did stimulate FSH synthesis, in the presence as well as absence of inhibin-like activity. The present results indicate that LH-RH-stimulated release of FSH is not affected by inhibin-like activity. Complete inhibition of basal release and synthesis of FSH does not prevent LH-RH from stimulating FSH release and synthesis. It is suggested that two separate releasing mechanisms for FSH could exist in the pituitary gland.
在完整雌性大鼠垂体在存在抑制素样活性的情况下进行长期孵育期间，促性腺激素释放激素（LH-RH）刺激的促卵泡激素（FSH）释放经过4小时孵育后受到抑制。然而，与此同时基础FSH释放也受到抑制。因此，首先将腺体在存在抑制素样活性的情况下孵育4小时以完全阻断基础释放，此后向培养基中加入LH-RH。结果发现，尽管持续存在抑制素样活性，LH-RH仍然能够刺激FSH释放。这意味着LH-RH刺激的FSH释放可以与基础释放分开研究。采用这种孵育方式发现，LH-RH对FSH释放的部分作用独立于蛋白质合成。LH-RH刺激的FSH释放的一部分也独立于细胞外Ca2+的存在。此外还发现，在孵育4小时后加入LH-RH，无论有无抑制素样活性，均能刺激FSH合成。目前的结果表明，LH-RH刺激的FSH释放不受抑制素样活性的影响。对FSH基础释放和合成的完全抑制并不能阻止LH-RH刺激FSH释放和合成。提示垂体中可能存在两种独立的FSH释放机制。
