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Ligand-activated signal transduction in the 2-cell embryo.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Lu, David P. Li, Yan Bathgate, Roslyn Day, Margot O'Neill, Christopher |
| Copyright Year | 2003 |
| Abstract | Platelet-activating factor (PAF) is an autocrine trophic/survival factor for the preimplantation embryo. PAF induced an increase in intracellular calcium concentration ([Ca2+]i) in the 2-cell embryo that had an absolute requirement for external calcium. L-type calcium channel blockers (diltiazem, verapamil, and nimodipine) significantly inhibited PAF-induced Ca2+ transients, but inhibitors of P/Q type (omega-agatoxin; omega-conotoxin MVIIC), N-type (omega-conotoxin GVIA), T-type (pimozide), and store-operated channels (SKF 96365 and econazole) did not block the transient. mRNA and protein for the alpha1-C subunit of L-type channels was expressed in the 2-cell embryo. The L-type calcium channel agonist (+/-) BAY K 8644 induced [Ca2+]i transients and, PAF and BAY K 8644 each caused mutual heterologous desensitization of each other's responses. Depolarization of the embryo (75 mM KCl) induced a [Ca2+]i transient that was inhibited by diltiazem and verapamil. Whole-cell patch-clamp measurements detected a voltage-gated channel (blocked by diltiazem, verapamil, and nifedipine) that was desensitized by prior responses of embryos to exogenous or embryo-derived PAF. Replacement of media Ca2+ with Mn2+ allowed Mn2+ influx to be observed directly; activation of a diltiazem-sensitive influx channel was an early response to PAF. The activation of a voltage-gated L-type calcium channel in the 2-cell embryo is required for normal signal transduction to an embryonic trophic factor. |
| Starting Page | 55 |
| Ending Page | 68 |
| Page Count | 14 |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://www.biolreprod.org/content/early/2003/02/19/biolreprod.102.014696.full.pdf |
| PubMed reference number | 12606379v1 |
| Volume Number | 69 |
| Issue Number | 1 |
| Journal | Biology of reproduction |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | Blastocyst structure Blood Platelets Calcium Channel Agonists Calcium Channel Blockers Calcium ion Conotoxin Diltiazem Econazole Embryo KCL compound L-Type Calcium Channels Manganese Cation (2+) Nifedipine Nimodipine Pimozide SK&F 96365 Schisandra glabra Signal Transduction Verapamil autocrine hypersensitivity desensitization omega-Conotoxin GVIA omega-Conotoxins voltage |
| Content Type | Text |
| Resource Type | Article |
