Christianson S L, Zalesky D D, Grotjan H E
Continental Grain Company, Wayne Feed Division, Lincoln, NE 68516, USA.
Domest Anim Endocrinol. 1998 Mar;15(2):87-92. doi: 10.1016/s0739-7240(97)00082-9.
The heterogeneity of luteinizing (LH) is hormonally regulated with androgens having been reported to increase the percentage of extremely basic LH isohormones in the ovine pituitary. This study re-examined the effects of androgens on the heterogeneity of LH in the ovine pituitary because the extremely basic isoforms of LH reported previously were subsequently demonstrated to be artifacts resulting from the conditions used for chromatofocusing. Pituitary extracts from wethers, rams, and dihydrotestosterone (DHT)-implanted wethers were desalted by flow dialysis and chromatofocused on pH 10.5 to 7.0 gradients. LH was quantitated by radioimmunoassays. When compared with rams, wethers had increased percentages of LH isoforms eluting between pH 9.6 and 10. Patterns of intrapituitary LH isohormones were comparable in rams and DHT-implanted wethers except that rams had a higher percentage of LH eluting at pH 9.2 (20.9 +/- 2.1% vs. 13.3 +/- 1.3%). In contrast to what was previously reported, rams and DHT-implanted wethers had higher percentages of ovine LH isoforms eluting at pH's 9.4 or lower. Thus, androgens alter LH heterogeneity yielding increased percentages of isohormones eluting at pH's of 9.4 or lower.
促黄体生成素（LH）的异质性受激素调节，据报道雄激素可增加绵羊垂体中极碱性LH同工激素的百分比。本研究重新审视了雄激素对绵羊垂体中LH异质性的影响，因为先前报道的LH极碱性同工型随后被证明是用于色谱聚焦的条件所导致的假象。对去势公羊、公羊和植入二氢睾酮（DHT）的去势公羊的垂体提取物进行流动透析脱盐，并在pH 10.5至7.0的梯度上进行色谱聚焦。通过放射免疫测定法定量LH。与公羊相比，去势公羊在pH 9.6至10之间洗脱的LH同工型百分比增加。公羊和植入DHT的去势公羊垂体中LH同工激素的模式相当，只是公羊在pH 9.2处洗脱的LH百分比更高（20.9±2.1%对13.3±1.3%）。与先前报道的相反，公羊和植入DHT的去势公羊在pH 9.4或更低时洗脱的绵羊LH同工型百分比更高。因此，雄激素改变LH异质性，导致在pH 9.4或更低时洗脱的同工激素百分比增加。
