Gilligan A, Kawamura H, Vaitukaitis J L
Mol Cell Endocrinol. 1986 Jul;46(2):155-62. doi: 10.1016/0303-7207(86)90094-8.
To determine if human luteinizing hormone (hLH) follows the same subcellular route in the pseudo-pregnant rat ovary as human chorionic gonadotropin (hCG), the distribution of immunoreactive and bioactive hLH within cytosol, lysosomes, and a combined plasma membrane/prelysosomal vesicle fraction was examined. Immunoreactive levels were determined using a specific radioimmunoassay and bioactive levels were determined in an in vitro Leydig cell bioassay. Low cytosolic hLH levels were apparent the first few hours after hLH administration and may reflect at least some contamination by serum and interstitial fluid. Plasma membrane/prelysosomal vesicles attained the highest hLH concentration 1 h after hLH injection, after which hLH levels declined rapidly until barely detectable levels were observed at 18 h. The hormone in this fraction was receptor bound and exhibited the highest bioactivity of the three fractions examined. Lysosomal hLH concentrations were highest at 12 after hLH injection and were maintained at high levels through 18 h. Substantial amounts of lysosomal hLH appeared to be receptor bound but this hormone was not bioactive. In situ degradation of the oligosaccharides may have occurred while lysosomal hLH was receptor bound. Lysosomal degradation is the major pathway for hLH inactivation as has been described for hCG. However, hLH may be degraded within lysosomes more quickly than hCG. The differential subcellular distribution of immunoreactive and bioactive hLH provides strong support for hLH internalization and degradation within ovarian luteal cells.
为了确定人促黄体生成素（hLH）在假孕大鼠卵巢中的亚细胞途径是否与人类绒毛膜促性腺激素（hCG）相同，研究了免疫反应性和生物活性hLH在细胞溶质、溶酶体以及质膜/溶酶体前体小泡组合部分中的分布情况。使用特异性放射免疫测定法测定免疫反应水平，并通过体外睾丸间质细胞生物测定法测定生物活性水平。给予hLH后的最初几个小时，细胞溶质中的hLH水平较低，这可能至少反映了血清和间质液的一些污染。质膜/溶酶体前体小泡在注射hLH后1小时达到最高hLH浓度，此后hLH水平迅速下降，直到18小时时几乎检测不到。该部分中的激素与受体结合，在所检测的三个部分中表现出最高的生物活性。溶酶体hLH浓度在注射hLH后12小时最高，并在18小时内保持在高水平。大量溶酶体hLH似乎与受体结合，但这种激素没有生物活性。溶酶体hLH与受体结合时，可能发生了寡糖的原位降解。溶酶体降解是hLH失活的主要途径，正如对hCG所描述的那样。然而，hLH在溶酶体内的降解可能比hCG更快。免疫反应性和生物活性hLH在亚细胞水平上的差异分布为hLH在卵巢黄体细胞内的内化和降解提供了有力支持。
