LYSOPHOSPHATIDIC ACID INDUCES A PERTUSSIS TOXIN-SENSITIVE CA2+-ACTIVATED CL- CURRENT IN XENOPUS-LAEVIS OOCYTES
LYSOPHOSPHATIDIC ACID INDUCES A PERTUSSIS TOXIN-SENSITIVE CA2+-ACTIVATED CL- CURRENT IN XENOPUS-LAEVIS OOCYTES
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DOI：
10.1152/ajpcell.1992.263.4.c896
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发表时间：
1992-10-01
影响因子：
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通讯作者：
MOORMAN, JR
中科院分区：
文献类型：
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作者：
DURIEUX, ME;SALAFRANCA, MN;MOORMAN, JR
溶血磷脂酸（LPA）诱导去卵泡非洲爪蟾卵母细胞的Ca ~（2+）激活的Cl-电流。该反应似乎是由特定的膜受体介导的，因为当细胞外应用相关化合物[磷脂酸（PA）、溶血磷脂酰胆碱（LPC）和溶血磷脂酰丝氨酸（LPS）]或当细胞内注射LPA时，不会诱导电流。在百日咳毒素中孵育可防止反应。该反应由Ca 2+激活的Cl-电流介导，因为1）它被细胞内乙二醇-双（β-氨基乙基醚）-N，N，N '，N'-四乙酸（EGTA; 5 mM）消除，但不受细胞外Ca 2+浓度变化的影响，和2）在较低Cl-浓度下逆转电位变得更正。苏拉明（2 mM）阻断LPA诱导的电流，但PA、LPS、LPC和血小板活化因子拮抗剂WEB-2086不能。LPA浓度为10（-8）至10（-3）M时，响应呈剂量依赖性。卵母细胞在LPA中孵育不诱导生殖囊泡破裂。这些研究结果表明，这种新的卵母细胞对LPA的反应是由一个特定的膜受体介导的百日咳毒素敏感的G蛋白。
Lysophosphatidic acid (LPA) induces a Ca2+-activated Cl- current in defolliculated Xenopus laevis oocytes. The response appears mediated by a specific membrane receptor, because no current is induced when related compounds [phosphatidic acid (PA), lysophosphatidylcholine (LPC), and lysophosphatidylserine (LPS)] are applied extracellularly or when LPA is injected intracellularly. Incubation in pertussis toxin prevents the response. The response is mediated by a Ca2+-activated Cl- current because 1) it is abolished by intracellular ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA; 5 mM) but not affected by changes in extracellular Ca2+ concentration and 2) the reversal potential becomes more positive at lower Cl- concentrations. Suramin (2 mM) blocks the LPA-induced current, but PA, LPS, LPC, and the platelet-activating factor antagonist WEB-2086 do not. The response is dose dependent for LPA concentrations from 10(-8) to 10(-3) M. Incubation of oocytes in LPA does not induce germinal vesicle breakdown. These findings suggest that this novel oocyte response to LPA is mediated by a specific membrane receptor linked to a pertussis toxin-sensitive G protein.