长期应用左旋精氨酸对慢性低氧肺动脉平滑肌细胞钾通道的作用  

The effects of long-term application of L-arginine on K^+ channel in pulmonary artery smooth muscle cells from rats exposed to chronic hypoxia

作　　者：张永昶[1] 倪望[1] 甄国华 张珍祥[1] 徐永健[1] 

机构地区：[1]华中科技大学同济医学院附属同济医院呼吸疾病研究室,武汉430030

出　　处：《中华结核和呼吸杂志》2003年第2期93-96,共4页Chinese Journal of Tuberculosis and Respiratory Diseases

基　　金：国家自然科学基金资助项目 ( 39970 332 )

摘　　要：目的　探讨长期应用左旋精氨酸 (L Arg)对慢性低氧大鼠肺动脉平滑肌细胞 (PASMC)膜钾通道的作用 ,为慢性低氧性肺动脉高压的防治手段提供理论依据。方法　雄性Wistar大鼠 18只 ,每组 6只 ,随机分为三组 :生理盐水对照组 (A组 )、慢性低氧组 (B组 )和慢性低氧 +L Arg组 (C组 )。单个大鼠的PASMC获得采用急性酶分离法 (胶原酶Ⅰ型和木瓜蛋白酶 )。用全细胞膜片钳技术测定三组PASMC的静息膜电位 (Em)、电压门控钾通道 (Kv通道 )电流和钙激活钾通道 (KCa通道 )电流。结果　 (1)B组大鼠PASMC的静息膜电位为 (- 31± 8)mV ,A组为 (- 4 2± 5 )mV ,两组比较差异有显著性 (P <0 0 1)。C组大鼠PASMC的静息膜电位为 (- 39± 4 )mV ,与B组比较差异有显著性 (P <0 0 5 )。(2 )对Kv通道 (在 +5 0mV电压刺激时峰值电流 ) :B组大鼠PASMC的峰值电流为 (6 2± 5 )pA/pF ,A组为 (12 1± 9)pA/pF ,两组比较差异也有显著性 (P <0 0 1)。C组大鼠PASMC的峰值电流为 (95± 3)pA/pF ,与B组比较差异也有显著性 (P <0 0 0 1)。 (3)对KCa通道 (+5 0mV电压刺激时的峰值电流 ) :B组大鼠PASMC的峰值电流为 (74 7± 4 1)pA/pF ,A组为 (5 3 6± 5 9)pA/pF ,两组比较差异有显著性 (P <0 0 5 )。应用L Arg后 。Objective To investigate the effects of long term application of L arginine (L Arg) on K + channel in pulmonary artery smooth muscle cells (PASMC) from rats exposed to chronic hypoxia Methods Male Wistar rats were randomly divided into three groups:group A (control group) , group B (chronic hypoxia group) and group C (chronic hypoxia plus L Arg treatment group) The rats were exsanguinated and the intrapulmonary arteries (300～700 OD) were collected Single PASMC was obtained by the acute enzyme separation method (collagnase Ⅰplus papain) and the conventional whole cell patch clamp technique was used to record resting membrane potential (Em), potassium ion currents of voltage gated potassium channel and Ca 2+ sensitive potassium channel Results (1) The Em of group B[(-31±8) mV, n =6] was significantly higher than that of group A [(-42±5) mV, n =6, P <0 01] After long term application of L Arg, the Em of group C [(-39±4) mV, n =6] was significantly lower than that of group B ( P <0 05) (2) The peak current at +50 mV of voltage gated potassium channel was compared among three groups In group B [(62 2±5 3) pA/pF, n =6], it was significantly lower than that of group A [(121±9)pA/pF, n =6] ( P <0 01) After long term application of L Arg, the peak current at +50 mV of voltage gated potassium channel in group C [(95±3)pA/pF, n =6] was significantly higher than that of group B( P <0 001) (3) The peak current at +50 mV of Ca 2+ sensitive potassium channel was compared among three groups In group B [(74 7±4 1) pA/pF, n =6], it was significantly higher than that of group A [(53 6±5 9)pA/pF, n =6] ( P <0 05) After long term application of L Arg, the peak current at +50 mV of Ca 2+ sensitive potassium channel in group C [(31 8±1 8)pA/pF, n =6] was significantly lower than that of group B [(74 7±4 1)pA/pF, n =6] ( P <0 001) Conclusions The long term application of L Arg can improve the rest

关 键 词：左旋精氨酸 肺动脉平滑肌细胞 钾通道 慢性低氧肺动脉高压 慢性肺心病 

分 类 号：R543.2[医药卫生—心血管疾病] R541.5[医药卫生—内科学]