Localization of 3 beta-hydroxysteroid dehydrogenase in the chicken ovarian follicle shifts from the theca layer to granulosa layer with follicular maturation.
3 beta-Hydroxysteroid dehydrogenase (3 beta-HSD) catalyzes the conversion of pregnenolone to progesterone in the delta 4-3-ketosteroid metabolic pathway and dehydroepiandrosterone to androstenedione in the delta 5-3 beta-hydroxysteroid pathway. It has been suggested that small follicles of the chicken ovary that have not entered the follicular hierarchy metabolize steroids via the delta 5-3 beta-hydroxysteroid pathway, whereas preovulatory follicles that have entered the hierarchy metabolize steroids via the delta 4-3-ketosteroid pathway. Our objective was to localize 3 beta-HSD in follicles of the chicken ovary by immunocytochemistry using an anti-human placental 3 beta-HSD polyclonal antiserum to identify steroidogenic cells that convert pregnenolone to progesterone and/or dehydroepiandrosterone to androstenedione. Three groups of follicles of different maturities were examined: small follicles (1-10 mm in diameter and that have not entered the hierarchy), preovulatory follicles (10-35 mm in diameter and that have entered the hierarchy), and the most recent postovulatory follicle. Chicken ovaries were obtained 2 h after oviposition and fixed with Bouin's solution. Tissues were dehydrated with a series of ethanol, embedded in Paraplast (Brunswick Company, St. Louis, MO), and sectioned. Sections (4 microns) were immunostained for 3 beta-HSD with a Rabbit ExtrAvidin Staining Kit (Sigma Chemical Co., St. Louis, MO). 3 beta-HSD was localized in the single theca layer of cortical follicles (approximately 1 mm in diameter), which are still embedded in the stromal tissue, and in the theca interna and externa of other small follicles (< 10 mm in diameter). No immunoreactivity was observed in the granulosa layer of the majority of small follicles.(ABSTRACT TRUNCATED AT 250 WORDS)
Nitta
H
H
Department of Animal Sciences, University of Illinois, Urbana 61801.
Mason
J I
JI
Bahr
J M
JM
D015096:3-Hydroxysteroid Dehydrogenases / Q000378:metabolism*; D000818:Animals; D002645:Chickens; D005260:Female; D006107:Granulosa Cells / Q000201:enzymology; D007150:Immunohistochemistry; D006080:Ovarian Follicle / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D013799:Theca Cells / Q000201:enzymology
D015096:3-Hydroxysteroid Dehydrogenases