M受体及其亚型与逼尿肌功能的关系研究

Relationship of muscarinic receptor and its subtypes to detrusor function in rats

目的 探讨M受体亚型与逼尿肌功能变化之间的关系。方法 根据膀胱压力容积测定结果将动物分为稳定组和不稳定组 ,通过体外肌条拉力试验记录不同M受体及其受体活性药物作用下逼尿肌肌条自发性收缩频率及收缩力变化。结果 正常大鼠中逼尿肌不稳定发生率为 2 5 6%。在一定张力下逼尿肌有自发性收缩产生。不稳定组体外肌条自发性收缩频率及收缩力较稳定组升高。阿托品、4 DAMP和Methoctramin对肌条自发性收缩频率无影响。卡巴可能使自发性收缩频率和收缩力增加 ,阿托品和4 DAMP可部分抑制这种作用 ,Methoctramin作用不明显。结论 逼尿肌自律性不依赖M受体及其亚型 ,肌源性因素是逼尿肌不稳定产生的重要原因。

Objective To investigate the relationship of muscarinic receptor and its subtypes to the function of detrusor. Methods A total of 43 rats were divided into stable group and instable group accordine to cystometry changes of urodynamics were monitored with cystometric studies. Spontanouse contraction frequency and strength of detrusor strips mustarded respectively by carbachol (muscarinic receptor agonist), atropine (nonselective M antagonist), methoctramin (M 2 receptor selected antagonist), and 4 DAMP (M 3 receptor selected antagonist) were measured. Results In 43 rats, rats with Destrusor Instability(DI) took up 25 6%.Bladders of DI rats showed less capacity, lower compliance, and lower hyperreflexia. Detrusor of the 2 groups contracted at a certain tension. The spontaneous contraction frequency and strangth of destrusor strips in instable group was higher than those in stable group. There were no obvious changes when detrusor strips were mustarded by different muscarinic receptor antagonists. Carbachol raised detrusor strips′ spontaneous contraction frequency ,which were blocked partly by atropine and 4 DAMP but not by Methoctramin. Conclusions Detrusor is a rythmatic tissue at a certain tension. Rise of Exitability of detrusor is the main cause of DI. M 3 receptor can improve the exitability of detrusor and cause direct contraction of detrusor. The function of M 2 receptor is still unclear.