The effects of long-term application of L-arginine on K+ channel in pulmonary artery smooth muscle cells from rats exposed to chronic hypoxia
- Author:
- No author available
- Journal Title:
- CHINESE JOURNAL OF TUBERCULOSIS AND RESPIRATORY DISEASES
- Issue:
- 2
- DOI:
- 10.3760/j:issn:1001-0939.2003.02.009
- Key Word:
- 低氧;肺动脉;离子通道
Abstract： 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(-42±5)mV,两组比较差异有显著性(P<0.01).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<0.05).(2)对Kv通道(在+50 mV电压刺激时峰值电流):B组大鼠PASMC的峰值电流为(62±5) pA/pF,A组为(121±9)pA/pF,两组比较差异也有显著性(P<0.01).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<0.001).(3)对KCa通道(+50mV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(53.6±5.9)pA/pF,两组比较差异有显著性(P<0.05).应用L-Arg后,C组大鼠PASMC的峰值电流为(31.8±1.8)pA/pF,与B组比较差异也有显著性(P<0.001).结论长期应用L-Arg可改善慢性低氧大鼠PASMC的静息膜电位,增加PASMC电压门控钾通道电流,降低慢性低氧时而升高了的钙激活钾通道电流,从而有助于防治慢性低氧性肺动脉高压.
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