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Comment |
Shi F, et al 2004 reported Cell-Specific Expression and Regulation of Soluble Guanylyl Cyclase {alpha}1 and {beta}1 Subunits in the Rat Ovary.
Soluble guanylyl cyclase (sGC) is activated by nitric oxide (NO) and carbon monoxide (CO), resulting in cGMP production. Recent studies indicate that NO and cGMP influence ovarian functions. However, little information is available regarding the ovarian expression of sGC. This study examined sGC alpha1 and beta1 subunit protein levels in the ovary during postnatal development, gonadotropin-induced follicular growth, ovulation, and luteinization, and in cultured rat granulosa cells. In postnatal rats, sGC alpha1 subunit immunoreactivity was high in granulosa cells of primordial and primary follicles on Day 5, but was low in granulosa cells of larger follicles on Days 10 and 19. Theca cells of developing follicles, but not stromal cells, also demonstrated moderate sGC alpha1 immunoreactivity. In gonadotropin-treated immature rats, intense sGC alpha1 subunit staining was similarly observed in granulosa cells of primordial and primary follicles, but was low in granulosa cells of small antral follicles and undetectable in granulosa cells of large antral and preovulatory follicles. Following ovulation, corpora lutea expressed moderate sGC alpha1 immunoreactivity. Similar ovarian localization and expression patterns were seen for sGC beta1, indicting regulated coexpression of sGC subunits. Immunoblot analysis revealed no change in total ovarian sGC alpha1 and beta1 subunit protein levels during gonadotropin treatment. Similarly, there was no apparent effect of FSH on sGC subunit protein levels in cultured granulosa cells. These findings indicate regulated, cell-specific patterns of sGC expression in the ovary, and are consistent with roles of cGMP in modulating ovarian functions.
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