Childs G V, Unabia G, Tibolt R, Lloyd J M
Department of Anatomy and Neurosciences, University of Texas Medical Branch, Galveston 77550.
Endocrinology. 1987 Nov;121(5):1801-13. doi: 10.1210/endo-121-5-1801.
Gonadotropes from cycling female rats were studied to investigate possible mechanisms for the nonparallel release of LH and FSH. The percentages of total gonadotropes increased from 14% during estrus (E) to 18% by diestrous day 2. More of these cells became multihormonal on the morning of proestrus (P; from 46% during diestrus to 69%). Since LH-containing cells increased from 7% at E to 13.3% during early proestrus, this suggests that monohormonal FSH cells may have contributed by synthesizing LH. Gonadotrope cell areas were greatest just before the LH surge (P 1600 h). Microdensitometric measurements demonstrated that the amount and density of immunoperoxidase stain for either gonadotropin subunit were highest during the midafternoon of P. Interestingly, the amount of stain for LH continued to increase during the LH surge, suggesting that the stain had detected newly synthesized LH beta. At the same time, the average density of the LH beta stain decreased. In contrast, the amount, concentration, and density of stain for FSH beta increased during the afternoon of P and decreased during late P and early E. The percentages of granules that contained immunogold stains for only LH or FSH (monohormonal granules) at P 1600-P 1700 h were 3-4 times higher than those in diestrous rats. The percentages of monohormonal LH granules declined during the proestrous surge, whereas percentages of monohormonal FSH granules declined during the first rise (P 1900 h) and after the second rise in serum FSH (E 0800 h). Finally, the average number of gold particles per micron 2 granule area rose over the value in diestrous rats during P 1600-P 1700 h. These studies suggest that multihormonal gonadotropes support nonparallel gonadotropin release by changing the rate of subunit packaging and transit in the Golgi complex.
对处于发情周期的雌性大鼠的促性腺激素细胞进行了研究，以探究促黄体生成素（LH）和促卵泡生成素（FSH）非平行释放的可能机制。促性腺激素细胞总数的百分比从发情期（E）的14%增加到动情后期第2天的18%。在发情前期（P）的早晨，更多的这些细胞变成了多激素细胞（从动情期的46%增加到69%）。由于含LH的细胞从发情期的7%增加到发情前期早期的13.3%，这表明单激素FSH细胞可能通过合成LH做出了贡献。促性腺激素细胞面积在LH峰前（P 1600 h）最大。显微密度测定显示，在发情前期的下午中段，两种促性腺激素亚基的免疫过氧化物酶染色量和密度最高。有趣的是，在LH峰期间，LH染色量持续增加，表明该染色检测到了新合成的LHβ。与此同时，LHβ染色的平均密度降低。相比之下，FSHβ的染色量、浓度和密度在发情前期下午增加，在发情后期和发情期早期降低。在P 1600 - P 1700 h，仅含LH或FSH免疫金染色的颗粒（单激素颗粒）百分比比动情期大鼠高3 - 4倍。单激素LH颗粒的百分比在发情前期峰期间下降，而单激素FSH颗粒的百分比在第一次升高（P 1900 h）和血清FSH第二次升高后（E 0800 h）下降。最后，在P 1600 - P 1700 h，每平方微米颗粒面积的金颗粒平均数量超过了动情期大鼠的值。这些研究表明，多激素促性腺激素细胞通过改变亚基在高尔基体中的包装和转运速率来支持促性腺激素的非平行释放。
