Korean J Fertil Steril.  2003 Dec;30(4):269-280.

The effect of Ni2+ on the intracellular Ca2+ increase of the mouse early 2-cell embryos

• Yoon SY
• Lee EM
• Bae IH

Abstract

OBJECTIVE
We reported the overcoming effect of Ni2+ on the in vitro 2-cell block of mouse embryos. In this study, we aim to investigate whether Ni2+ should induce intracellular Ca2+ transient in the mouse embryos.
MATERIALS AND METHODS
Embryos were collected at post hCG 32hr from the oviduct of the ICR mouse and cultured in M2 medium omitted phenol red. Intracellular Ca2+ was checked by using a confocal laser scanning microscope and fluo-3AM by using various intracellular Ca2+ antagonists.
RESULTS
In 1mM Ni2+ treated medium which contained Ca2+(1.71mM), 75.7% of the embryos showed [Ca2+]i transient about 200 sec later. In the Ca2+-free medium, 69.8% of the embryos showed [Ca2+]i transient. In U73122, phospholipaseC(PLC) inhibitor (5uM, 10min) pretreated group, 33.3% of the embryos showed [Ca2+]i transient. Heparine, inositol 1,4,5-triphosphate receptor(IP3R) antagonist preinjected embryos showed no response with 1mM Ni2+. In danthrolene treatment, ryanodine receptor(RyR)-antagonist, 43% embryos showed [Ca2+]i transient but they showed delayed response about 340sec in the presence of Ca2+.
CONCLUSIONS
Summing up the above results, Ni2+ seems to induce Ca2+-release from the Ca2+-store even in the Ca2+-free medium. IP3 receptors of the mouse 2-cell embryos might have an essential role for the intracellular Ca2+ increase by Ni2+.

Keyword

mouse in vitro 2-cell block; intracellualr Ca2+ increase; Ni2+; IP3 antagonist; ryanodine receptor antagonist

MeSH Terms

Animals
Embryonic Structures*
Heparin
Inositol 1,4,5-Trisphosphate
Inositol 1,4,5-Trisphosphate Receptors
Mice*
Mice, Inbred ICR
Oviducts
Phenolsulfonphthalein
Ryanodine
Heparin
Inositol 1,4,5-Trisphosphate
Inositol 1,4,5-Trisphosphate Receptors
Phenolsulfonphthalein
Ryanodine