PLC-PKC途径参与腺苷类似物激活50pS钾离子通道过程  

The PLC-PKC pathway involves adenosine analog-induced activation of 50 pS K channel

作　　者：李文楠[1] 徐影[1] 孔淑敏[1] 王丽君[1] 隋洪玉[1] 刘玉杰[1] 范丽丽[1] 谷力[1] 谷瑞民[1] 

机构地区：[1]哈尔滨医科大学生物制药教研室,黑龙江哈尔滨150081

出　　处：《哈尔滨医科大学学报》2010年第2期107-110,共4页Journal of Harbin Medical University

基　　金：国家自然科学基金项目(30570673)

摘　　要：目的观察腺苷类似物cyclohexyladenosine(CHA)对大鼠肾小管髓袢升支粗段(medullary thick ascendinglimb,mTAL)管周膜钾离子通道的作用是否通过磷脂酶C-蛋白激酶C途径(phospholipase C-protein kinase C path-way,PLC-PKC pathway)。方法取SD大鼠肾小管髓袢升支粗段放置于倒置显微镜下的浴槽内,利用单通道膜片钳技术观察髓袢升支粗段管周膜钾离子通道活性改变。结果5μmol/L CHA对mTAL管周膜钾离子通道有激活作用(P<0.05)。在加入CHA基础上,分别加入PLC的抑制剂U-73122和PKC的抑制剂Calphostin C,钾离子通道的活性增加(P<0.05)。在加入CHA基础上,加入PKC的激活剂phorbol 12-myristate 13-acetate(PMA),通道活性降低(P<0.05)。结论激活PLC-PKC途径影响CHA对mTAL管周膜50 pS钾离子通道的激活作用。Objective To study the effect of adenosine on the basolateral K channel in the medullary thick ascending limb（mTAL）of the kidney,and to access the regulating effects of phospholipase C-protein kinase C（PLC-PKC）pathway on basolateral K channel.Methods SD rats were killed by cervical dislocation,and the kidneys were cut to thin coronal sections.After the collagenase treatment,the TAL was dissected and the isolated tubule was transferred onto a cover glass that was placed in a chamber mounted on an inverted microscope.The basolateral membrane of cells were patched,which had no sign of swelling and a clear board to their neighbor cells.Results The basolateral 50 pS K channel activity was stimulated by application of 5 μmol/L cyclohexyladenosine（CHA）,an adenosine analog,and the product of channel open probability and channel number（NPo）were increased from 0.20 to 0.59 in cell-attached patches.The stimulatory effect of CHA was blocked by activation of protein kinase C（PKC）with phorbol 12-myristate 13-acetate（PMA）.The open probability was progressively reduced by application of PMA（5 μmol/L）and the open probability was decreased from 0.58 to 0.07.In contrast,the effect of CHA on channel activity was strongly increased by inhibiting PKC with Calphostin C（5 μmol/L）.NPo was increased from 0.51 to 0.90 by inhibiting of PKC.The effect of U-73122,an inhibitor of phospholipase C（PLC） was examined in the presence of CHA.The channel activity was increased from 0.54 to 0.88 by inhibition of PLC.Conclusion PLC and PKC effect adenosine analog CHA-induced activity of 50 pS K channel in the mTAL of rat kidney.

关 键 词：腺苷类似物 钾离子通道 蛋白激酶C 磷脂酶C 

分 类 号：R334.1[医药卫生—人体生理学]