Conley A J, Kaminski M A, Dubowsky S A, Jablonka-Shariff A, Redmer D A, Reynolds L P
Department of Animal and Range Sciences, North Dakota State University, Fargo 58105, USA.
Biol Reprod. 1995 May;52(5):1081-94. doi: 10.1095/biolreprod52.5.1081.
Follicular and luteal morphology and steroidogenic function were investigated by immunohistochemistry for cytochrome P450 17 alpha-hydroxylase (P450c17) and 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) during the estrous cycle in pigs, sheep, and cows. The theca interna of all species expressed P450c17 during follicular development. In the pig, this constituted a continuous layer of cells around the follicle, but a sheath of cells lining the basement membrane appeared not to express P450c17. Neither was expression of P450c17 in ovine and bovine follicles uniform throughout the theca interna. In these two species, a beaded appearance was given by P450c17, since it was expressed in some regions but not in others. Therefore, staining for P450c17 defined functional sub-populations of cells within the theca interna of pigs, sheep, and cows. Ovulation was associated with a decrease in P450c17 in all species, but some expression persisted in theca-derived cells of developing and mature porcine CL. Expression of 3 beta-HSD in the preovulatory follicle was confined to the theca of the pig and sheep; in contrast, in the cow, it was highest in the granulosa. In general, 3 beta-HSD expression appeared to be greater in porcine than ovine or bovine follicles, the physiological relevance of which is discussed. Porcine and ovine theca continued to express 3 beta-HSD after ovulation, and granulosa-derived cells increased their 3 beta-HSD expression markedly as they luteinized in all three species. During early luteal development in pigs and sheep, theca-derived cells with high 3 beta-HSD encircled luteal lobules, but these cells appeared throughout the parenchyma of the mature CL. Luteal regression in sheep and cows was typified by the loss of many cells expressing 3 beta-HSD, whereas others, adjacent to them, appeared to be intact without loss of enzyme expression. These data further define differences in steroidogenesis during follicular and luteal development among the pig, sheep, and cow.
采用免疫组织化学方法，对猪、绵羊和奶牛发情周期中卵泡和黄体的形态以及类固醇生成功能进行了研究，检测细胞色素P450 17α-羟化酶（P450c17）和3β-羟基类固醇脱氢酶（3β-HSD）。在卵泡发育过程中，所有物种的卵泡内膜均表达P450c17。在猪中，这构成了围绕卵泡的连续细胞层，但衬于基底膜的细胞鞘似乎不表达P450c17。在绵羊和牛的卵泡中，P450c17在卵泡内膜中的表达也不均匀。在这两个物种中，P450c17呈现出串珠状外观，因为它在某些区域表达而在其他区域不表达。因此，P450c17染色可界定猪、绵羊和奶牛卵泡内膜内的功能性细胞亚群。排卵与所有物种中P450c17的减少有关，但在发育中和成熟猪黄体的卵泡膜来源细胞中仍有一些表达。排卵前卵泡中3β-HSD的表达局限于猪和绵羊的卵泡膜；相反，在牛中，它在颗粒细胞中表达最高。一般来说，猪卵泡中3β-HSD的表达似乎比绵羊或牛卵泡中的表达更强，文中讨论了其生理相关性。排卵后，猪和绵羊的卵泡膜继续表达3β-HSD，并且在所有三个物种中，颗粒细胞来源的细胞在黄体化时其3β-HSD表达显著增加。在猪和绵羊黄体发育早期，具有高3β-HSD的卵泡膜来源细胞环绕黄体小叶，但这些细胞在成熟黄体的实质中均有出现。绵羊和奶牛黄体退化的特征是许多表达3β-HSD的细胞丢失，而与之相邻的其他细胞似乎完好无损，酶表达未丢失。这些数据进一步明确了猪、绵羊和奶牛在卵泡和黄体发育过程中类固醇生成的差异。
