Sann H, Rössler W, Hammer K, Pierau F K
Max-Planck-Institut für physiologische und klinische Forschung, W. G. Kerckhoff-Institut, Bad Nauheim, F.R.G.
Neuroscience. 1992 Aug;49(3):699-713. doi: 10.1016/0306-4522(92)90238-w.
To elucidate the possible functional significance of sensory neuropeptides in visceral organs of mammals and birds the distribution, binding sites and the effects on ureteric peristalsis of substance P and calcitonin gene-related peptide (CGRP) were investigated in the ureter of guinea-pigs and chickens. In the guinea-pig numerous substance P and CGRP-immunoreactive fibres were located in the adventitia, smooth muscle layer, submucosa and occasionally in the epithelium. Varicose peptidergic fibres were often found on blood vessels. Binding sites for substance P were associated with blood vessels and epithelium in the following density order: venules greater than epithelium greater than arterioles. The highest density of CGRP binding sites was detected on the smooth muscle; venules and arterioles expressed moderate binding. The peristalsis frequency of the isolated ureter of the guinea-pig was increased by neurokinin A and substance P, whereas CGRP inhibited ureteric motility. In the chicken the immunoreactivity to substance P and CGRP was less pronounced. Immunoreactive fibres were found in the submucosa close to the epithelium and around ureteric ganglion cells. Correspondingly, substance P binding sites were located in the epithelium and in ureteric ganglia; however, specific CGRP binding was restricted to large blood vessels. In the chicken none of the sensory neuropeptides affected ureteric motility. Only high doses of the sensory neurotoxin capsaicin (greater than 10 microM) repeatedly produced a non-specific inhibitory effect, similar to that found in a capsaicin-desensitized guinea-pig ureter preparation. The data suggest that in the guinea-pig ureter sensory neuropeptides play a modulatory role in the regulation of ureteric motility and might have vascular and epithelial functions. In the chicken, substance P might be involved in the regulation of epithelial function and modulation of ganglionic transmission. The physiological or pathophysiological role of sensory neuropeptides and the efferent functions of afferent fibres appears to be much better developed in the guinea-pig than in the chicken.
为阐明感觉神经肽在哺乳动物和鸟类内脏器官中可能的功能意义，研究了P物质和降钙素基因相关肽（CGRP）在豚鼠和鸡输尿管中的分布、结合位点及其对输尿管蠕动的影响。在豚鼠中，大量P物质和CGRP免疫反应性纤维位于外膜、平滑肌层、黏膜下层，偶尔也见于上皮。在血管上常发现有曲张的肽能纤维。P物质的结合位点与血管和上皮相关，其密度顺序为：小静脉＞上皮＞小动脉。在平滑肌上检测到CGRP结合位点的密度最高；小静脉和小动脉表达中度结合。神经激肽A和P物质可增加豚鼠离体输尿管的蠕动频率，而CGRP则抑制输尿管运动。在鸡中，对P物质和CGRP的免疫反应性较弱。在靠近上皮的黏膜下层和输尿管神经节细胞周围发现了免疫反应性纤维。相应地，P物质结合位点位于上皮和输尿管神经节中；然而，特异性CGRP结合仅限于大血管。在鸡中，感觉神经肽均不影响输尿管运动。只有高剂量的感觉神经毒素辣椒素（大于10μM）反复产生非特异性抑制作用，类似于在辣椒素脱敏的豚鼠输尿管制备物中发现的作用。数据表明，在豚鼠输尿管中，感觉神经肽在输尿管运动调节中起调节作用，可能具有血管和上皮功能。在鸡中，P物质可能参与上皮功能调节和神经节传递调节。感觉神经肽的生理或病理生理作用以及传入纤维的传出功能在豚鼠中似乎比在鸡中发展得更好。
