These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Strontium promotes calcium oscillations in mouse meiotic oocytes and early embryos through InsP3 receptors, and requires activation of phospholipase and the synergistic action of InsP3.
    Author: Zhang D, Pan L, Yang LH, He XK, Huang XY, Sun FZ.
    Journal: Hum Reprod; 2005 Nov; 20(11):3053-61. PubMed ID: 16055456.
    Abstract:
    BACKGROUND: Sr2+ is the most efficient agent for mouse oocyte activation and functions by inducing Ca2+ oscillations. However, its specific mechanism of action remains unknown. Here we investigated the specificity and possible mechanism of Sr2+-induced Ca2+ oscillations in mouse oocytes and early embryos. METHODS: Ca2+ oscillations in oocytes and embryos were measured by ratiometric fluorescence imaging using fura-2AM. The role of phospholipase C (PLC) and inositol trisphosphate (InsP3) receptors in Sr2+-induced Ca2+ oscillations was examined by selective inhibitors. RESULTS: Sr2+ can induce Ca2+ oscillations in both immature and mature oocytes, and in early embryos. A cell cycle stage-dependent phenomenon to Sr2+ stimulation was observed in 1-cell embryos. By using a low molecular weight heparin to antagonize the function of InsP3 receptors, we were able to show that InsP3 receptors are essential for Sr2+-induced Ca2+ oscillations. Treating metaphase II (MII) oocytes with the PLC inhibitor, U73122, abolished Sr2+-induced increases in Ca2+. This inhibitory effect of U73122 could be rescued by microinjection of InsP3, indicating that Sr2+-induced Ca2+ oscillations require the synergistic action of InsP3. CONCLUSIONS: Sr2+-induced calcium oscillations in mouse oocytes and early embryos are mediated through InsP3 receptors, and require PLC activation and the synergistic action of InsP3.
    [Abstract] [Full Text] [Related] [New Search]