Receptors for neurotransmitters in Auerbach's plexus of Hirschsprung's disease ; A comparison with animal models

我们研究了内皮素ET_B受体突变型先天性神经节病（AR）大鼠及Hirselisprung病大鼠肠壁内内皮素（EL）和P物质等神经递质受体的变化与大肠运动功能障碍的关系。我们用我们新开发的方法来分析受体动力学；采用三种实验技术的受体定量成像系统，1)受体功能位点的体外放射配体结合技术，2)受体蛋白成熟位点的定量放射免疫组织技术，以及3)35S-cRNA探针受体生产位点的原位杂交技术。我们在患者和AR大鼠的奥尔巴赫神经丛的主要细胞（胆碱能神经元细胞体）和结肠小肠胶质中发现了ET_B受体的存在。使用我们的方法，我们证实了发现^1^2^ 5irl1620，一个选择性的ET_B受体的放射性配体，仅仅结合到从Hirschsprung病患者分离的具有aurbach 's丛的结肠部分。在本例患者中，我们使用我们的方法未能检测到P物质受体代偿性增加。有趣的是，在另一名先天性巨结肠病患者中，没有观察到^1^2^5I-1RL1620的异常结合，然而，Anerbach神经丛中P物质受体的表达量非常低。因此，我们证实了ETB受体在巨结肠疾病发病中的病理生理学意义，以及该疾病可能存在的另一种基因缺陷。一种调节P物质受体功能的因子可能有助于发现巨结肠病的异质性。

We examined the changes in receptors of neurotransmitters such as endothelin (EL) and substance P in the intestinal wall related to the dysfunction of large-intestinal motility in Hirselisprung disease and its animal model of congenital aganglionosis (AR) rat, the rat with a mutant endothelin ET_B receptor. We used our newly-developed method for analyzing the receptor dynamics ; the quantitative receptor-imaging system with three experimental techniques, 1) in vitro radioligand-binding technique for functional sites of receptors, 2) quantilative radioimnunohistochernical technique for sites of receptor proteins maturation, and 3) in situ hybridization technique for production sites of receptors with 35S-cRNA probes. We found the existence of ET_B receptors in the main principal cell (cholinergic neuronal cell body) in Auerbach's plexus, and small enteroglia in the colon of patients and AR rats. With the use of our methods, we confirmed the finding that ^1^2^5IRL162O, a selective radioligand for the ET_B receptor, merely bound to the section of colon with Aucrbach's plexus isolated from a patient with Hirschsprung's disease. In this case of patient, we failed to detect a compensatory increase of substance P receptor, using our method. Interestingly, in another patient with Hirschsprung's disease no abnormal binding of ^1^2^5I-1RL1620 was observed, however, a very lower amount of the expression of substance P receptor in Anerbach's plexus. Thus, we confirmed the pathopliysiological significance of the ETB receptor in the onset of Hirschsprung disease, and the possible another gene-defect in this disease. A factor regulating substance P receptor function may shed some light on the discovery of the heterogeneity of Hirschsprung's disease.