P物质对大鼠骶髓后连合核神经元甘氨酸激活的氯电流的调控(英文)  

MODULATION OF GLYCINE ACTIVATED CHLORIDE CURRENTS BY SUBSTANCE P IN RAT SACRAL DORSAL COMMISSURAL NEURONS

作　　者：徐天乐[1] 李继硕[2] 

机构地区：[1]中国科学技术大学生命科学学院神经生物学与生物物理学系,合肥230027 [2]第四军医大学基础部解剖学教研室,梁銶锯脑研究中心西安710032

出　　处：《生理学报》1999年第4期361-370,共10页Acta Physiologica Sinica

基　　金：国家自然科学基金

摘　　要：采用制霉菌素穿孔膜片箝技术， 研究了Ｐ物质（ｓｕｂｓｔａｎｃｅ Ｐ，ＳＰ） 对急性分离的大鼠骶髓后连合核神经元士的宁敏感性甘氨酸（ｇｌｙｃｉｎｅ ，Ｇｌｙ） 反应的调控作用。在箝制电压为－ ４０ ｍＶ时，ＳＰ在１ ｎｍｏｌ／Ｌ～１ μｍｏｌ／Ｌ之间呈浓度依赖性地增强３０ μｍｏｌ／Ｌ甘氨酸激活的氯电流。ＳＰ既不改变ＩＧｌｙ 的翻转电位， 也不影响Ｇｌｙ 与其受体的亲和力。Ｓｐａｎｔｉｄｅ 和选择性ＮＫ１ 受体拮抗剂，Ｌ６６８ ，１６９ ， 可阻断ＳＰ的增强作用， 而选择性ＮＫ２ 受体拮抗剂，Ｌ６５９ ，８７７ 则不能阻断ＳＰ对ＩＧｌｙ 的增强作用， 提示ＳＰ对ＩＧｌｙ 的增强作用是由ＮＫ１ 受体介导的。在不同的神经元上，ｃｈｅｌｅｒｙｔｈｒｉｎｅ 或ＫＮ６２ 可去除ＳＰ对ＩＧｌｙ 的增强作用， 提示蛋白激酶Ｃ或钙离子／ 钙调素依赖性的蛋白激酶Ⅱ可能参与了ＳＰ对ＩＧｌｙ 增强作用的胞内机制。以上结果提示，ＳＰ可能通过增强Ｇｌｙ 的反应而抑制脊髓伤害性信息的传导。The modulatory effect of substance P (SP) on strychnine sensitive glycine (Gly) response was examined in neurons acutely dissociated from the rat sacral dorsal commissural nucleus (SDCN) using nystatin perforated patch recording configuration under voltage clamp conditions. Application of SP potentiated 30 μmol/L Gly activated chloride current ( I Gly ) in a concentration dependent manner over the range of 1 nmol/L to 1 μmol/L at a holding potential of -40 mV. SP neither changed the reversal potential of Gly response nor affected the affinity of Gly to its receptor. The SP potentiation effect could be blocked by spantide as well as a selective NK 1 receptor antagonist, L 668,169, but not by NK 2 receptor antagonist, L 659,877. The facilitatory action of SP on I Gly could also be abolished by pretreatment with chelerythrine or KN 62 in different neurons, a finding suggesting that protein kinase C (PKC) or Ca 2+ /calmodulin dependent protein kinase Ⅱ (CaMKⅡ) possibly contributes to an intracellular pathway of SP in the augmentation of I Gly . The results imply that SP may suppress nociception in the spinal cord by potentiating Gly response.

关 键 词：P物质 甘氨酸 骶髓后连合核 氯 电生理 

分 类 号：Q424[生物学—神经生物学] Q422[生物学—生理学]