Mechanisms of peptidergic regulation of muscle movements in molluscs.

1.从非洲巨型蜗牛的中枢神经系统、心脏和口腔肌肉中分离到20多种兴奋性或抑制性神经肽。其中，对FMRFamide、ACEP-1、Achatin-I和Fulicin的功能和分布进行了研究。虽然FMRFamide、ACEP-1和Achain-I是从该动物的心房中分离出来的，但它们对心房没有明显的直接作用，但对心室有很强的兴奋作用。免疫组织化学研究表明，FMRFamide和ACEP-1样物质丰富地分布于大脑和食道下神经节、神经桩、通向心脏和心房的肠神经的许多神经元中，但在脑室中很少分布。这些在神经节合成的多肽可能被运输到心房的神经纤维，然后释放到脑室，在那里它们发挥作用。关于颊肌运动，已鉴定出2对脑神经节细胞和10对颊神经节神经元，并对其形态和功能进行了研究。其中，有两个制度是有特色的。1.5-羟色胺能神经元v-CDN兴奋地调制由胆碱能运动神经元B4放电引起的神经根牵引器收缩。另一种是胆碱能运动神经元B10含有神经肽ACEP-1，ACEP-1可能通过突触前作用于神经末梢，增加ACh1的释放。以阴茎拉肌为生物测定系统，研究了黄腐素的构效关系，并用免疫组织化学方法研究了该多肽的分布和定位。结论：黄腐素在生理上参与了阴茎牵引肌收缩的调节。

1. More than twenty kinds of excitatory or inhibitory neuropeptides have been isolated from the central nervous system, heart and buccal muscles of the African giant snail Achatina fulica. Among them, the function and distribution of FMRFamide, ACEP-1, achatin-I and fulicin were investigated.2. Although FMRFamide, ACEP-1 and achain-I were isolated from the atria of this animal, they did not show any significant direct effects on the atrium but did show strong excitatory effects on the ventricle.Immunohistochemical investigation has revealed that FMRFamide- and ACEP-1-like substances are richly distributed in many neurons in the cerebral and subesophageal ganglia, neuropile, intestinal nerve going to the heart, and atrium, but very scarcely in the ventricle. It is probable that these peptides synthesized in the ganglia are transported to the nerve fibers in the atrium and then released to the ventricle where they exhibit their actions.3. In relation to the buccal muscle movements, two pairs of cerebral ganglionic neurons and ten pairs of buccal ganglionic neurons have been identified and their morphology and function have been investigated. Among them two systems are characteristic. One; the contraction of the radula retractor elicited by the firing of cholinergic motoneuron B4 is modulated excitatorily by serotonergic neuron v-CDN. The other; a cholinergic motoneuron B10 contains neuropeptide ACEP-1, and the contraction of the radula protractor is modulated by ACEP-1 possibly acting presynaptically to the nerve terminals to increase the release of ACh.4. Structure-activity relationships of fulicin were studied by using the penis retractor muscle as a bioassay system, and the distribution and localization of this peptide were investigated immunohistochemically. It was concluded that fulicin is involved physiologically in the regulation of contraction of the penis retractor muscle.