Calcium effects on progesterone accumulation and oocyte maturation in cultured follicles of Rana pipiens.

@article{Francisco1986CalciumEO,
  title={Calcium effects on progesterone accumulation and oocyte maturation in cultured follicles of Rana pipiens.},
  author={Santiago Francisco and Allen W. Schuetz},
  journal={The Journal of experimental zoology},
  year={1986},
  volume={240 2},
  pages={
          265-73
        }
}
Pituitary homogenates (FPH) provoke a cascade of responses in the amphibian ovarian follicle, culminating in progesterone biosynthesis and oocyte maturation (GVBD). Calcium may play an important role as an intracellular second messenger in regulating these physiological responses. Experiments were carried out on cultured, isolated follicles of Rana pipiens to assess the effects of varying extracellular calcium on follicular progesterone accumulation and oocyte maturation. In hormonally… 
Sources of calcium and the involvement of calmodulin during steroidogenesis and oocyte maturation in follicles of Rana pipiens.
TLDR
Experiments using calcium antagonists suggest that Ca2+, acting through calmodulin at some specific step(s) distal to cAMP elevation and prior to pregnenolone formation, is involved in FPH-induced progesterone accumulation, apparently with the participation of both extracellular and intracellular pools of Ca2+.
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The Role of Chloride Channels and Chloride Ions in Regulation of Steroidogenesis in the Gonads of Amphibians, Birds, and Mammals
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References

SHOWING 1-10 OF 24 REFERENCES
Dichotomous effects of forskolin on somatic and germ cell components of the ovarian follicle: evidence of cAMP involvement in steroid production and action.
TLDR
The data provide evidence that in amphibians, as in mammals, pituitary hormones regulate steroid hormone production by follicle cells via a cyclic AMP system and control of oocyte maturation induction appears to be determined by the relative levels of cAMP present in the follicles and oocytes.
Insulin induction of meiosis of rana pipiens oocytes: Relation to endogenous progesterone
TLDR
It was concluded that increased endogenous progesterone facilitates GVBD induction by insulin, and direct evidence that insulin's action on the follicle wall involves steroid production is provided.
Mechanisms by which calcium ions regulate the steroidogenic actions of luteinizing hormone in isolated ovarian cells in vitro.
TLDR
It is suggested that calcium ions significantly modulate LH-stimulated progesterone biosynthesis in isolated ovarian cells in vitro and at intracellular loci distal to the actual generation of cAMP.
Calcium ions modulate hormonally stimulated progesterone production in isolated ovarian cells.
TLDR
It is suggested that Ca2+ may influence one or more processes distal to, or independent of, cyclic AMP generation, and the susceptibility of progesterone biosynthesis to inhibition by trifluoperazine suggests a possible role for calmodulin in the ovary.
Effect of calcium ion on the maturation of cumulus-enclosed pig follicular oocytes isolated from medium-sized graafian follicles.
TLDR
It was found that the lowest concentration of Ca2+ required for oocyte maturation was around 0.0265-0.053 mM, and maintenance of oocytes in a nondegenerated state also requires the constant presence ofCa2+ in the culture medium.
The roles of Ca and Mg in starfish oocyte maturation induced by 1-methyladenine
TLDR
The data suggest that free-diffusable Mg++ was necessary for hormone action during the critical hormone-dependent period, while extracellular Ca++ was important for hormone binding, and indicates that 1-MA regulates oocyte permeability to Ca and Mg during oocyte maturation.
The calcium-calmodulin system: participation in the regulation of steroidogenesis at different stages of granulosa cell differentiation.
TLDR
Findings indicate that the calcium-calmodulin system is involved in the regulation of granulosa cell steroidogenesis by both FSH and LH, and its participation in the gonadotropic regulation is independent of the stage of follicular maturation and cellular differentiation.
Mechanisms subserving calcium's modulation of luteinizing hormone action in isolated swine granulosa cells.
TLDR
Calcium ions significantly modulate LH's stimulation of pregnenolone biosynthesis from endogenous cholesterol substrate in swine ovarian cells, and this effect was specific to swine granulosa cells.
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