کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10904739 1086690 2007 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Autocrine activation of ion currents in the two-cell mouse embryo
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی تحقیقات سرطان
پیش نمایش صفحه اول مقاله
Autocrine activation of ion currents in the two-cell mouse embryo
چکیده انگلیسی
The actions of autocrine ligands are required for the normal development of the preimplantation embryo in vitro. These ligands act as survival factors for the preimplantation stage embryo. One autocrine ligand, paf (1-o-alkyl-2-acetyl-sn-gylcero-3-phosphocholine), induced a dihydropyridine-sensitive calcium transient in the zygote and two-cell embryo, and these transients were required for the normal preimplantation stage survival. Paf induces an influx of external calcium through a dihydropyridine-sensitive channel. Dihydropyridine-sensitive currents are voltage-regulated, yet to date there is no evidence of membrane voltage depolarization in the two-cell embryo. To define the paf-induced calcium influx we have examined the response of the membrane potential and ion currents to paf in two-cell embryos. An initial response to paf challenge was the expression of an ion current (− 15.6 ± 1.6 pA) that was dependent upon extracellular calcium, was not voltage-gated but was dihydropyridine (nifedipine)-sensitive. This calcium current was followed (91 ± 6 s after paf) by a net outward current (284 ± 59 pA) that was composed of 4,4′-diisothiocyanatostilbene-2,2′-disulfonate-sensitive (anion channel blocker) and tetraethylammonium chloride-sensitive (K+ channel blocker) currents. This current corresponded temporally with a marked paf-induced transient hyperpolarization of the membrane potential (− 8.4 ± 1.2 mV) that was dependent upon the generation of the calcium transient. The results directly demonstrate the activation of a voltage-independent calcium current in response to paf and show for the first time the expression of an afterhyperpolarization that occurs as a response to the calcium transient.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Experimental Cell Research - Volume 313, Issue 13, 1 August 2007, Pages 2786-2794
نویسندگان
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