title: Neomycin blocks substance P-induced calcium entry in cultured rat spinal cord neurons.
abstract: Substance P (SP) plays an important role in sensitization of spinal cord neurons. In this study, we investigated SP-induced calcium activities in cultured rat spinal cord neurons with confocal laser scanning microscopy. Our results showed that SP increased [Ca(2+)](i) by calcium entry rather than release from intracellular calcium stores. Neomycin (100 microM), an antagonist of phosphatidylinositol 4,5-bisphosphate (PIP(2)), blocked SP-induced calcium entry. Ca(2+)-free medium induced capacitative entry, which was significantly potentiated by SP. As activation of SP receptor (NK-1) leads to production of inositol 1,4,5-trisphosphate (IP(3)) by PIP(2) turnover, the results indicates that SP-induced calcium entry and SP-potentiated capacitative calcium entry might be mediated or regulated by IP(3)/diacylglycerol (DG) pathway.
authors.affiliation: Key Laboratory of Neurobiology, Shanghai Institute of Physiology, Chinese Academy of Sciences, 320 Yue-Yang Road, 200031, P.R., Shanghai, China.
authors.forename: Z S
authors.initials: ZS
authors.lastname: Zhou
authors.forename: Y S
authors.initials: YS
authors.lastname: Shu
authors.forename: Z Q
authors.initials: ZQ
authors.lastname: Zhao
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000187:drug effects* / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D004622:Embryo, Mammalian; D018613:Microscopy, Confocal; D009355:Neomycin / Q000494:pharmacology*; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D013116:Spinal Cord / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D013373:Substance P / Q000378:metabolism* / Q000494:pharmacology*
chemical_list: D015220:Calcium Channels; D013373:Substance P; D009355:Neomycin; D002118:Calcium