Localization of androgen receptor and cytochrome P450 aromatase in the follicle and corpus luteum of the porcine ovary

The following study was undertaken to localize androgen receptors (AR) and aromatase cytochrome P450 (P450arom) in porcine ovarian tissue because ovar ian androgens may act locally to modulate follicular and luteal function in various species. Androgen receptor was detected immunohistochemically in g ranulosa and theca cells of preantral as well as in growing antral follicle s. The most intensive staining was observed in the antral granulosa layer. Luteinizing granulosa cells of preovulatory follicles. and luteal cells fro m the early and midluteal phases rained weakly for the androgen receptor. F ully regressed corpora lutea in the early follicular phase of the next cycl e did nor stain for androgen receptor. in contrast. granulosa cells were ve ry weakly stained for aromatase in early stages of follicular development. The P450arom was maximally expressed with the same intensity in mural and a ntral layers in large ovulatory follicles. Corpora lutea from the early lut eal phase showed positive staining, whereas those from midluteal phase did not stain for aromatase. some cells of regressed corpora lutea unexpectedly exhibited aromatase staining. (C) 2001 Elsevier Science B.V. All rights re served.