Tomita Y, Kaneko S, Funayama M, Kondo H, Satoh M, Akaike A
Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, Japan.
Neurosci Lett. 1998 Jun 5;248(3):195-8. doi: 10.1016/s0304-3940(98)00362-0.
To elucidate whether rat transient receptor potential (TRP-R), a rat TRP4 homolog, functions as a store-operated Ca2+ channel (SOC), we have measured the Ca2+ entry after thapsigargin treatment in Xenopus oocytes injected with mRNA for TRP-R. While non-injected oocytes elicited an SOC response, significantly larger responses were observed in the oocytes expressing TRP-R. The oocyte-native SOC response was inhibited by injection of antisense oligodeoxyribonucleotide for mammalian TRP1. When Ca2+ concentration-SOC response curve was examined, the EC50 value was much smaller in oocytes expressing TRP-R than that of non-injected oocytes. These results suggest that TRP-R functions as SOC having higher sensitivity to external Ca2+ than amphibian TRP1 channel.
为了阐明大鼠瞬时受体电位（TRP-R），一种大鼠TRP4同源物，是否作为储存操纵性钙通道（SOC）发挥作用，我们在注射了TRP-R mRNA的非洲爪蟾卵母细胞中测量了毒胡萝卜素处理后的钙内流。未注射的卵母细胞引发了SOC反应，而在表达TRP-R的卵母细胞中观察到了明显更大的反应。通过注射针对哺乳动物TRP1的反义寡脱氧核糖核苷酸，卵母细胞天然的SOC反应受到了抑制。当检测钙浓度-SOC反应曲线时，表达TRP-R的卵母细胞中的EC50值比未注射的卵母细胞小得多。这些结果表明，TRP-R作为SOC发挥作用，对细胞外钙的敏感性高于两栖动物TRP1通道。
