5-HT和NA增强大鼠骶髓后连合核神经元甘氨酸门控Cl^-通道电流由蛋白激酶介导

Enhancement of Glycine Gated Cl - Channel Currents by 5 HT and NA in Rat Sacral Dorsal Commissural Neurons is Mediated by Protein Kinases

用制霉菌素穿孔膜片钳方法研究５－ＨＴ和ＮＡ对急性分离的大鼠骶髓后连合核神经元甘氨酸门控氯离子通道电流（ＩＧｌｙ）的调控作用及其胞内机制。发现：（１）５－ＨＴ激活与非胰岛激活蛋白（ＩＡＰ）敏感型Ｇ蛋白偶联的５－ＨＴ２受体亚型，激活磷脂酶Ｃ（ＰＬＣ），增加甘油二酯（ＤＡＧ）的生成。ＤＡＧ增强不依赖Ｃａ２＋的新型ＰＫＣ（ｎＰＫＣ）的活性，从而增强ＩＧｌｙ；（２）ＮＡ激活与ＩＡＰ敏感型Ｇ蛋白偶联的α２受体，抑制腺苷酸环化酶（ＡＣ），减少ｃＡＭＰ的生成，使ＰＫＡ活性降低，从而增强ＩＧｌｙ。

The effects of 5 HT and NA on glycine gated Cl - channel currents(I Gly ) and its intracellular mechanisms were investigated in acutely dissociated rat sacral dorsal commissural neurons by using nystatin perforated patch clamp recording. It was found that:(1) the activation of 5 HT 2 receptor coupled to IAP insensitive G proteins increases intracellular DAG formation through the activation of phospholipase C(PLC). The accumulation of DAG increases the Ca 2+ independent or novel PKC(nPKC) activity, resulting in the potentiation of I Gly ; (2) the activation of α 2 adrenoceptor by NA coupled to IAP sensitive G proeins reduces intracellular cAMP formation through the inhibition of adenylyl cyclase (AC). The reduction of cAMP decreases PKA activity, resulting in the potentiation of I Gly .