Role of Calcium in the Action of LHRH on Ovarian Progesterone Production

  • Peter C. K. Leung
  • Jian Wang


In fura-2AM-loaded rat granulosa cells, [Ca++]i rapidly increased after addition of LHRH (10-6M). The effect of LHRH on [Ca++]i changes could be completely blocked by an LHRH antagonist. In a 5-h incubation, combined treatment of granulosa cells with LHRH and EDTA caused a 45% decrease in P production induced by LHRH. Concomitant treatment with EDTA plus TPA caused a 30% reduction in P accumulation when compared with TPA treatment alone. In a 24-h incubation, concomitant treatment with FSH plus LHRH markedly decreased P accumulation induced by FSH. Addition of EDTA to the cells partially reversed the inhibitory effect of LHRH upon FSH-induced P formation, by ca. 25%. Likewise, the inhibitory effect of TPA on P production could be partially reversed by the concomitant presence of 1 mM EDTA. Further, the reversal effect of EDTA could be completely abolished by the simultaneous addition of 1 mM Ca++, and P production went down to the same levels as those induced by TPA alone. These data further support the hypothesis that the action of LHRH on ovarian steroidogenesis is mediated, at least in part, by a Ca++-dependent protein kinase C.


Granulosa Cell Progesterone Production Ovarian Granulosa Cell Ovarian Steroidogenesis Intracellular Calcium Measurement 
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  1. 1.
    Ma F, Leung PCK. Luteinizing hormone-releasing hormone enhances polyphosphoinositide breakdown in rat granulosa cells. Biochem Biphys Res Commun 1985; 130:1201–8.CrossRefGoogle Scholar
  2. 2.
    Davis JS, West LA, Farese RV. Gonadotropin-releasing hormone (GnRH) rapidly stimulates the formation of inositol phosphates and diacylglycerol in rat granulosa cells: further evidence for the involvement of Ca2+ and protein kinase C in the action of GnRH. Endocrinology 1986; 118:2561–71.PubMedCrossRefGoogle Scholar
  3. 3.
    Burgess GM, Godfrey PP, McKinney JS, Berridge MJ, Irvine RF, Putney JW Jr. The second messenger linking receptor activations to internal Ca2+ release in liver. Nature 1984; 309:63–6.PubMedCrossRefGoogle Scholar
  4. 4.
    Nishizuka Y, Takei Y, Kishimoto A, Kikkawa U, Kaibuichi K. Phospholipid turnover in hormone actions. Recent Prog Horm Res 1984; 40:301–41.PubMedGoogle Scholar
  5. 5.
    Berridge MJ. Inositol trisphosphate and diacylglycerol as second messengers. Biochem J 1984; 820:345–60.Google Scholar
  6. 6.
    Grynkiewicz G, Poenie M, Tsien RY. A new generation of Ca2+ indicators with greatly improved fluorescence properties. J Biol Chem 1985; 260:3440–50.PubMedGoogle Scholar
  7. 7.
    Eckstein N, Eshel A, Eli Y, Ayalon D, Naor Z. Calcium-dependent actions of gonadotropin-releasing hormone agonist and luteinizing hormone upon cyclic AMP and progesterone production in rat ovarian granulosa cells. Mol Cell Endocrinol 1986; 47:91–8.PubMedCrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1989

Authors and Affiliations

  • Peter C. K. Leung
    • 1
  • Jian Wang
    • 1
  1. 1.Department of Obstetrics and GynecologyUniversity of British ColumbiaVancouverCanada

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