Tumor necrosis factor-alpha (TNF-alpha) inhibits steroidogenesis of bovine ovarian granulosa and thecal cells in vitro. Involvement of TNF-alpha receptors.
The effect of recombinant bovine tumor necrosis factor-alpha (TNF-alpha) on steroidogenesis and numbers of bovine ovarian granulosa and thecal cells has been studied, and specific binding sites for 125I-TNF-alpha on ovarian cells have been determined. Granulosa cells have been examined from small (surface diameter 1-5 mm) follicles, whereas thecal cells from large (> or = 8 mm) follicles were utilized. Increasing doses of TNF-alpha significantly attenuated insulin- and IGF-I-induced estradiol production by granulosa cells from small follicles, but had no effect on basal estradiol production. Moreover, TNF-alpha significantly attenuated insulin- and LH-induced androstenedione production by thecal cells from large follicles. TNF-alpha had little or no effect on the numbers of granulosa and thecal cells in these same studies. Specific high-affinity, low-capacity binding of 125I-TNF-alpha was also demonstrable in granulosa and thecal cells. Thus, it appears that TNF-alpha inhibits insulin- and IGF-I-induced estradiol production by granulosa cells and androstenedione production by thecal cells via TNF-alpha binding to its own receptor.
Spicer
L J
LJ
Department of Animal Science, Oklahoma State University, Stillwater 74078, USA. IGFLEO@okway.okstate.edu
D000735:Androstenedione / Q000096:biosynthesis; D000818:Animals; D002417:Cattle / Q000378:metabolism*; D002478:Cells, Cultured; D004958:Estradiol / Q000096:biosynthesis; D005260:Female; D006107:Granulosa Cells / Q000187:drug effects / Q000378:metabolism*; D007328:Insulin / Q000494:pharmacology; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D007986:Luteinizing Hormone / Q000494:pharmacology; D013256:Steroids / Q000096:biosynthesis*; D013799:Theca Cells / Q000187:drug effects / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D007328:Insulin; D013256:Steroids; D014409:Tumor Necrosis Factor-alpha; D000735:Androstenedione; D004958:Estradiol; D007334:Insulin-Like Growth Factor I; D007986:Luteinizing Hormone