慢性阻塞性肺疾病患者肺组织胆碱能M受体及其亚型的变化

Study on the muscarinic receptor and its subtypes in patients with chronic obstructive pulmonary disease

目的 了解慢性阻塞性肺疾病 (chronicobstructivepulmonarydisease ,COPD)患者肺组织M受体及其亚型的变化。方法 采用肺手术切除标本 ,分为COPD组和对照组 ,进行放射配体结合饱和实验和竞争抑制实验。结果 对照组与COPD组M受体密度分别为 (6 4± 10 )fmol/mg·protein和 (4 2±18)fmol/mg·protein ,COPD组明显低于对照组 (P <0 0 1) ,平衡解离常数 (KD)差异无显著性。对照组M1受体比例 (6 7 2± 2 7) %低于COPD组 (74 2± 4 8) % (P <0 0 5 ) ;对照组M2 受体比例 (2 9 3±1 7) %高于COPD组 (16 8± 4 4) % (P <0 0 1) ;对照组M3 受体比例 (3 6± 2 9) %低于COPD组 (9 3±4 1) % (P <0 0 5 )。结论 COPD患者M受体密度减低 ,但M1和M3 受体比例增加 ,M2 受体比例减少 。

Objective To investigate the M receptor and its subtypes in the lung tissue of patients with chronic obstructive pulmonary disease (COPD). Methods Muscarinic cholinergic receptors have been identified and characterized by radioligand binding assay in the lung tissue specimens of patients with COPD Competitive binding experiments with pirenzepine and methoctramine were used to characterize muscarinic subtypes. Results The contents of M receptor were (64±10), (42±18) fmol/mg. protein in normal group and COPD patients respectively No significant difference was observed in antagonist affinity(K D) among normal group and COPD patients The ratio of subtype M 1 was higher in COPD patients (67 2±2 7)% than in normal group (74 2±4 8)%, M 2 was lower [(29 3±1 7)% vs (16 8±4 4)%] and M 3 was higer [(3 6±2 9)% vs (9 3±4 1)%] respectively Conclusion The number of muscarinic cholinergic receptors is decreased in COPD patients, but the ratios of subtype M 1 and M 3 are increased and the subtype M 2 is decreased The changes of the distribution of the subtypes of M receptors is an important pathophysiologic change of COPD