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Updated: Aug 17, 2026

A Tissue Culture Model of Estrogen-producing Primary Bovine Granulosa Cells
Published on: September 6, 2018
Phospholipase C-beta and ovarian sex steroids in pig granulosa cells
M Lieberherr1, B Grosse, V Machelon
1The Centre National de la Recherche Scientifique, Jouy en Josas, France.
Abstract:
We compared the membrane effects of estradiol, progesterone, and androstenedione in a single experimental model, the ovarian granulosa cells collected from immature Large White sows. We measured changes in cytosolic free calcium concentration ([Ca2+]i) in confluent Fura-2 loaded cells. We used pharmacological tools and polyclonal phospholipase C-beta (PLC-beta) antibodies. Each steroid (0.1 pM to 1 nM) transiently increased intracellular calcium concentration ([Ca2+]i) within 5 sec. They mobilized Ca2+ from the endoplasmic reticulum as shown by using two phospholipase C inhibitors, neomycin and U-73122. Ca2+ mobilization involved PLC-beta1 for progesterone, PLC-beta2 for estradiol and PLC-beta4 for androstenedione. A pertussis toxin-insensitive G protein was involved in the effects of progesterone on Ca2+ mobilization whereas estradiol and androstenedione effects were mediated via a pertussis toxin-sensitive G-protein. Ca2+ influx from the extracellular milieu was involved in the increase in [Ca2+]i induced by progesterone and estradiol, but not by androstenedione. Influx of Ca2+ was independent of Ca2+ mobilization from calcium stores, and it was suggested that L-type Ca2+ channels for estradiol and T-type Ca2+ channels for progesterone were involved. The three steroids had no effect on cAMP. Rapid effects of progesterone, estradiol, and androstenedione involved a direct action on cell membrane elements such as PLC-beta, G-proteins, and calcium channels, and these mechanisms were hormone-specific.
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