Romańi P, Robertson D M, Diczfalusy E D
Acta Endocrinol (Copenh). 1977 Apr;84(4):697-712. doi: 10.1530/acta.0.0840697.
The levels of biologically active luteinizing hormone were determined by an in vitro bioassay method in plasma samples collected daily over a complete menstrual cycle from 12 menstruating women. These cycles were normal according to a number of criteria, including daily plasma levels of oestradiol, 17-hydroxyprogesterone and progesterone. Immunoreactive LH was estimated in the same 12 cycles by a radio-immunoassay (RIA) procedure (HCG-RIA) using an HCG antiserum and iodinated HCG. The 2nd IRP of HMG was selected as standard although significant deviations from parallelism were found with 7 out of the 12 plasma pools studied. The use of the 1st IRP of human pituitary gonadotrophins (FSH and LH (ICSH)) for bioassay (herafter HPG-1st IRP) as standard in this system resulted invariably in invalid assays, due to lack of parallelism. Immunoreactive LH was also measured in 8 of the 12 cycles by a RIA procedure (HLA-RIA) using a human LH antiserum and iodinated human LH of pituitary origin. Results are expressed in terms of the HPG-1st IRP. The plasma levels of biologically and immunologically active LH were qualitatively similar throughout the menstrual cycle. However, the LH levels measured by the bioassay invariably exceeded those estimated by the RIA procedures. The biological to immunological (B/I) ratio over the entire menstrual cycle (312 comparisons) was 5.5 with 95% confidence limits at 5.2 and 5.8 when the HCG-RIA system was employed. Using the HLH-RIA system (208 comparisons), the corresponding ratio was 6.4 (6.0:6.9). When regression lines were calculated using the bioassay results as the independent variable and the RIA results as the dependent variable, the 95% confidence limits of the regression lines did not include the origin. Furthermore,, in keeping with the high B/I ratios, the slopes of the two regression lines and their conficence limits differed markedly from unity. It is concluded that although qualitatively similar profiles were observed between the biological and immunological activities throughtout the menstrual cycle, two aspects require further attention. Firstly, the elevated B/I ratios together with the behaviour of the dose-effect lines obtained with different standards in the various RIA systems suggest that presently available reference standard preparations of pituitary and/or urinary origin are not suitable for the assay of LH in human plasms. Secondly, from the regression analyses of the biological and immunological activities it is infered that the RIA methods detect immunological activity which is not associated with biological activity. If so, the validity of these RIA procedures for specifically measuring low levels of biologically active LH in plasma may be in question.
采用体外生物测定法，对12名处于月经周期的女性在整个月经周期中每天采集的血浆样本中的生物活性促黄体生成素水平进行了测定。根据多项标准，包括雌二醇、17 - 羟孕酮和孕酮的每日血浆水平，这些月经周期是正常的。使用人绒毛膜促性腺激素抗血清和碘化人绒毛膜促性腺激素，通过放射免疫分析（RIA）程序（HCG - RIA）对相同的12个周期中的免疫反应性促黄体生成素进行了估计。尽管在所研究的12个血浆样本中有7个与平行性存在显著偏差，但仍选择人绝经期促性腺激素的第二国际参考品（IRP）作为标准品。在该系统中，将人垂体促性腺激素（促卵泡生成素和促黄体生成素（促间质细胞激素））的第一国际参考品（HPG - 1st IRP）用作生物测定的标准品，由于缺乏平行性，总是导致测定无效。还通过使用人促黄体生成素抗血清和垂体来源的碘化人促黄体生成素的RIA程序（HLA - RIA），对12个周期中的8个周期的免疫反应性促黄体生成素进行了测量。结果以HPG - 1st IRP表示。在整个月经周期中，生物活性和免疫活性促黄体生成素的血浆水平在质量上相似。然而，通过生物测定法测得的促黄体生成素水平总是超过RIA程序估计的水平。当采用HCG - RIA系统时，整个月经周期（312次比较）的生物活性与免疫活性（B/I）比值为5.5，95%置信限为5.2和5.8。使用HLH - RIA系统（208次比较），相应的比值为6.4（6.0:6.9）。当以生物测定结果作为自变量、RIA结果作为因变量计算回归线时，回归线的95%置信限不包括原点。此外，与高B/I比值一致，两条回归线的斜率及其置信限与1有显著差异。结论是，尽管在整个月经周期中生物活性和免疫活性之间观察到质量上相似的曲线，但有两个方面需要进一步关注。首先，升高的B/I比值以及在各种RIA系统中使用不同标准获得的剂量 - 效应线的行为表明，目前可用的垂体和/或尿源参考标准品制剂不适合用于测定人血浆中的促黄体生成素。其次，从生物活性和免疫活性的回归分析推断，RIA方法检测到的免疫活性与生物活性无关。如果是这样，这些RIA程序用于特异性测量血浆中低水平生物活性促黄体生成素的有效性可能存在问题。
