Plasma prolactin concentrations and testicular human chorionic gonadotropin binding sites during short photoperiod-induced testicular regression and recrudescence in the golden hamster.
Plasma prolactin concentrations and testicular human chorionic gonadotropin binding sites during short photoperiod-induced testicular regression and recrudescence in the golden hamster.
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金仓鼠短光周期诱导睾丸退化和复发期间的血浆催乳素浓度和睾丸人绒毛膜促性腺激素结合位点。
DOI：
10.1095/biolreprod25.3.536
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发表时间：
1981
影响因子：
3.6
通讯作者：
Goldman,BD
中科院分区：
文献类型：
--
作者：
Klemcke,HG;Bartke,A;Goldman,BD
在金黄地鼠中进行实验，以确定在短光周期诱导的睾丸退化和自发复发期间血浆PRL浓度和未占用睾丸hCG结合位点之间的时间关系和统计相关性。尽管两个实验提供了血浆PRL浓度和睾丸hCG结合之间的统计学显著性（P<0.02）相关性，但复发期间血浆PRL增加的开始变化阻止了关于可能的因果关系的任何明确结论。因此，这些数据并不表明PRL分泌增加的一段时间开始或最初是自发复发或自发复发期间睾丸hCG结合发生变化所必需的。自发性睾丸复发的开始时间是可变的，但总是与LH、FSH和PRL的血浆浓度升高相关。在短光照或长光照条件下，仓鼠睾丸都有一类高亲和力hCG结合位点，平均平衡结合常数（Ka）为3.06 × 1010 M −1。在前4周的短光周期，当睾丸重量没有变化时，睾丸hCG结合位点的浓度（fmol/mg蛋白质）和总含量（fmol/睾丸）均显著降低。然而，经过10周的短光周期，并继续通过16-18周，hCG结合位点的浓度增加，而总含量保持压抑，在退化的睾丸相比，睾丸hCG结合发现在长光周期仓鼠。使用[125 I] iodo-hCG或[125 I] iodo-hLH得到相同的结果。这种未被占据的hCG/hLH结合位点浓度的增加可能代表1）每个Leydig细胞的结合位点增加; 2）睾丸hCG结合位点的占据率降低或丢失减少，与血浆LH浓度降低相当;或3）与其他睾丸成分相比，睾丸退化时Leydig细胞数量相对增加。
Experiments were conducted in the golden hamster to determine temporal relationships and statistical correlations between plasma PRL concentrations and unoccupied testicular hCG binding sites during short photoperiod-induced testicular regression and spontaneous recrudescence. Although two experiments provided statistically significant (P<O.02) correlations between plasma PRL concentrations and testicular hCG binding, variability in onset of increased plasma PRL during recrudescence prevented any definite conclusions concerning a possible cause-and-effect relationship. Hence, the data do not indicate that a period of increased PRL secretion either initiates, or is initially necessary for, spontaneous recrudescence or changes in testicular hCG binding occurring during spontaneous recrudescence. Time of initiation of spontaneous testicular recrudescence was variable, but was always associated with increases in plasma concentrations of LH, FSH, and PRL. Testes from hamsters maintained in either short or long photoperiod had a single class of high affinity hCG binding sites with an average equilibrium association constant (Ka) of 3.06 × 1010M−1. During the first 4 weeks of short photoperiod, when no changes in testicular weights were found, there were significant decreases in both concentration (fmol/mg protein) and total content (fmol/testes) of testicular hCG binding sites. However, after 10 weeks of short photoperiod and continuing through 16–18 weeks, the concentration of hCG binding sites was increased, while total content remained depressed, in regressed testes when compared with testicular hCG binding found in long photoperiod hamsters. Use of either [125I] iodo-hCG or [125I] iodo-hLH gave identical results. This increased concentration of unoccupied hCG/hLH binding sites may represent 1) an increase in binding sites per Leydig cell; 2) decreased occupancy or decreased loss of testicular hCG binding sites commensurate with decreased plasma LH concentrations; or 3) a relative increase in numbers of Leydig cells compared with other testicular components as testes undergo regression.