Immunohistochemical Localization of 3β-Hydroxysteroid Dehydrogenase and P450 17α-Hydroxylase during Follicular and Luteal Development in Pigs, Sheep, and Cows1

Abstract

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.

Persistence of anti-zonae pellucidae antibodies following a single inoculation of porcine zonae pellucidae in the domestic equine

“…Representative follicles from ovaries (horse) and ovaries from bitches were fixed in 4% paraformaldehyde at 4 8C for 24 h and processed as previously described (Conley et al 1995). Immunocytochemical localization of antipZP antibodies was performed using the avidin-biotin-peroxidase complex method with a Vectastain Elite ABC kit (Vector Laboratories).…”

Luteinization of porcine preovulatory follicles leads to systematic changes in follicular gene expression

“…The expression of NR5A2 (liver receptor homolog-1), a transcription factor that activates transcription of steroidogenic genes, including aromatase (Sirianni et al 2002, Mendelson et al 2005 was also greater in preovulatory estrogenic follicles. 3-b-Hydroxysteroid dehydrogenase (3b-HSD) increased in preovulatory luteinized follicles; a change in gene expression that is known to occur during luteinization (Conley et al 1995, Driancourt et al 1998. There was also a predictable change in INHBB, AKR1C3, and PTGES (inhibin, b-B, prostaglandin F synthase, and prostaglandin E synthase; high in preovulatory follicles; Jiang et al 2004).…”

Immunolocalization of Inhibin/Activin Subunits and Steroidogenic Enzymes in Equine Neonatal Ovaries

“…The precise location of these inside the ovary has been studied using steroidogenic enzymes in recent years. Immunohistochemical observations of these steroidogenic enzymes have been reported in the ovaries of several species, including humans [22], bears [26,27], horses [1,2], dogs [21], raccoon dogs [31], pigs [11], sheep and cows [6]. However, there is little information available concerning the presence and distribution of these steroidogenic enzymes in mammalian newborns' ovaries.…”