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Nitric oxide-dependent activation of pig oocytes: role of calcium

Jaroslav Petr1, Radko Rajmon, Vilma Lánská

  • 1Research Institute of Animal Production, Prátelství 815, Prague 10, Uhríneves, Czech Republic.

Molecular and Cellular Endocrinology
|June 22, 2005
PubMed

Insights

Nitric oxide (NO) activates pig oocytes via calcium signaling. This NO-donor-induced oocyte activation depends on both extracellular calcium influx and intracellular calcium release, primarily through ryanodine receptors.

Area of Science:

  • Reproductive Biology
  • Cell Signaling
  • Oocyte Maturation

Background:

  • Nitric oxide (NO) plays a role in various physiological processes, including reproduction.
  • Understanding the mechanisms of oocyte activation is crucial for reproductive technologies.

Purpose of the Study:

  • To investigate the role of nitric oxide (NO) in the parthenogenetic activation of pig oocytes.
  • To elucidate the specific calcium mobilization pathways involved in NO-donor-induced oocyte activation.

Main Methods:

  • In vitro maturation of pig oocytes.
  • Treatment with NO-donor SNAP to induce parthenogenetic activation.
  • Use of calcium chelators (BAPTA-AM) and channel blockers (verapamil, procaine, ruthenium red) to investigate calcium sources.
  • Inhibition of inositol triphosphate receptors and ryanodine receptors.

Main Results:

  • SNAP treatment induced parthenogenetic activation of mature pig oocytes.
  • Oocyte activation was suppressed by BAPTA-AM, indicating calcium dependency.
  • Blocking extracellular calcium influx with verapamil reduced activation rates.
  • Inhibition of ryanodine receptors (procaine, ruthenium red) significantly reduced activation, while inositol triphosphate receptor blockers had no effect.

Conclusions:

  • Nitric oxide-donor-induced activation of pig oocytes is calcium-dependent.
  • Calcium is mobilized from both extracellular and intracellular sources.
  • Ryanodine receptors, not inositol triphosphate receptors, are key for intracellular calcium release during NO-induced oocyte activation.

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