English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

This study was designed to investigate whether porcine oocytes produce a factor(s) that influences cumulus and mural granulosa cell steroid production and to characterize the biochemical nature and mode of action of a such factor(s). Porcine cumulus-oocyte complexes (COC) were collected from 2-5 mm follicles and cultured either intact or after oocytectomy for 48 h. Steroid levels were then measured in the culture media. Conditioned media, obtained by culturing denuded oocytes for 48 h, were subjected to heat treatment of charcoal extraction and utilized to culture intact and oocytectomized COC. FSH-stimulated progesterone, 20 alpha-OH-progesterone, and estradiol were significantly higher in oocytectomized vs. intact COC cultures. Denuded oocytes cultured with granulosa cells significantly inhibited progesterone production compared to control. Also, media conditioned with different numbers of denuded oocytes (0 to 300) significantly inhibited progesterone production by oocytectomized COC in a manner dependent on oocyte number. Charcoal extraction, but not heat treatment, significantly removed the inhibitory effect of the conditioned media on progesterone production by oocytectomized COC. Increased progesterone production by oocytectomized COC was not accompanied by a similar increase in cAMP formation. Heptanol, a gap junction blocker, did not alter progesterone production by intact COC. In conclusion, porcine oocytes secrete a factor(s) that inhibits cumulus and mural granulosa cell steroidogenesis. This factor(s) is heat stable but extractable by charcoal. The factor(s) appears not to be transferred to somatic cells via gap junctions, and its effect is downstream of cAMP formation.

Regulation of Cumulus Cell Steroidogenesis by the Porcine Oocyte and Preliminary Characterization of Oocyte-Produced Factor(s)