BIOASSAY OF SERUM LUTEINIZING HORMONE (LH) AND CHORIONIC GONADOTROPIN

1975年，我们开发了LH生物测定术语RICT（大鼠间质 细胞睾酮）用于测量循环LH，5倍以上 灵敏度高于常规放射免疫分析法。 我们现在已经 开发了一种简单、快速的方法， 用于测量血浆、组织提取物或 孵育培养基。 该生物测定使用微量滴定板， 通过酶联免疫测定程序测定产品 使用转移固相。 手术可以在更短的时间内完成 超过5小时（而RICT超过24小时）， 试剂制备提出的原则和步骤可以是 也用于测定垂体和下丘脑激素，或 任何能刺激细胞释放的蛋白质激素 可以通过本方法测量的产品（即， 类固醇、环核苷酸、促性腺激素）。 我们使用RICT测定来评估LH分泌的生物活性， 对内源性和低剂量外源性GnRH的反应， 普通人 在体内不存在非特异性血浆效应， LH生物测定法的结果证明， LH生物活性水平尽管较低但可测量 10名低促性腺激素男性免疫活性。 正常男性 外源性低剂量（10 μ g）静脉注射GnRH导致 在生物活性LH的优先释放中， 中位血浆生物-免疫活性 LH比值。 这种模式模仿内源性LH 搏动性 血浆生物活性LH的优先增加， 对外源性或内源性GnRH的反应可能反映了 初始分布容积较小，代谢清除较慢 生物与免疫LH比率。 我们已经证明了一个持续的 促性腺激素释放激素对生物和免疫活性LH的抑制作用 拮抗剂（N-乙酰基-D-pCLPhel，2-D-Trp 3-D-Alal 0 GnRH 10） 绝经后妇女，并表明GnRH拮抗剂 与血清蛋白结合， 停留时间 这可以解释观察到的持续时间延长 拮抗剂的作用。

In 1975 we developed a LH bioassay term RICT (rat interstitial cell testosterone) for measurement of circulating LH, 5-fold more sensitive than conventional radioimmunoassay. We have now developed a simplified and rapid method of comparable sensitivity for the measurement of LH/hCG in plasma, tissue extracts or incubation media. This bioassay uses microtiter plates and the product is, measured by an enzyme-linked immunoassay procedure using transfer solid phase. The procedure can be caried out in less than five hours (versus greater than 24 hr. for RICT) with minimal reagent preparation. The principle and steps presented can be used also for the assay of pituitary and hypothalamic hormones or any protein hormone that can stimulate the release of a cell product which can be measured by the present approach (ie. steroid, cyclic nucleotide, gonadotropin). We used RICT assay to assess biological LH activity secreted in response to endogenous and low dose exogenous GnRH, pulses in normal men. The absence of non-specific plasma effects in the LH bioassay was demonstrated by the finding of undetectable levels of LH bioactivity despite low but measurable immunoactivity in 10 hypogonadotropic men. In normal men exogenous low dose (10 mu g) i.v. GnRH administration resulted in preferential release of bioactive LH, with a consequent significant increase in the median plasma bio- to immunoactive LH ratio. This pattern mimicked that of endogenous LH pulsatility. The preferential increase in bioactive plasma LH in response to exogenous or endogenous GnRH might reflect the smaller initial distribution volume and slower metabolic clearance rate of bio versus immuno LH. We have demonstrated a sustained inhibitory actions on bio and immunoactive LH of a potent GnRH antagonist (N-acetyl-D-pCLPhel,2-D-Trp3-D-Alal0GnRH10) in postmenopausal women, and shown that the GnRH antagonist binds avidly to serum proteins and has a prolonged plasma residence time. This may explain the observed extended duration of the antagonist action in vivo.