Díaz-Miranda L, Blanco R E, García-Arrarás J E
Department of Biology, University of Puerto Rico, Río Piedras 00931-3360.
J Comp Neurol. 1995 Feb 20;352(4):626-40. doi: 10.1002/cne.903520410.
Two peptides, Gly-Phe-Ser-Lys-Leu-Tyr-Phe-NH2 (GFSKLYFamide) and Ser-Gly-Tyr-Ser-Val-Leu-Tyr-Phe-NH2 (SGYSVLYFamide), recently isolated from the sea cucumber Holothuria glaberrima [Díaz-Miranda et al. (1992) Biol. Bull. 182:241-247] represent the first neuropeptides isolated from holothurians. Using an antibody against GFSKLYFa, we describe here the localization and distribution pattern of GFSKLYFa-like immunoreactivity in H. glaberrima, where immunoreactive fibers form a prominent and extensive peptidergic nervous system component. Neuron-like cells and nerve fibers expressing GFSKLYFa-like immunoreactivity are found in the ectoneural and hyponeural divisions of the radial nerve cords as well as in the digestive, haemal, respiratory, and reproductive systems; in the tentacles; and in tube feet. Neuroendocrine-like cells are found in the mucosal layer of the intestine. Ultrastructure immunocytochemical analysis revealed that, in nerve cells and fibers in the serosal layer of the intestine, the immunoreactivity is concentrated in vesicles. The immunoreactive nerve fibers are found mainly within a dense nerve plexus overlying and in close contact with smooth muscle cells of the intestine. The exclusive expression of GFSKLYFa-like immunoreactivity in neuronal or neuroendocrine tissue together with the close apposition of some fibers to muscle cells suggests that GFSKLYFa acts as a neuromuscular transmitter or neuromodulator in H. glaberrima. The wide occurrence of GFSKLYFa-like immunoreactivity throughout the nervous system of the sea cucumber suggests that GFSKLYFa plays an important role in the control of multiple action systems, including digestion, respiration, circulation, reproduction, and locomotion.
最近从光滑海参（Holothuria glaberrima）中分离出的两种肽，即甘氨酸 - 苯丙氨酸 - 丝氨酸 - 赖氨酸 - 亮氨酸 - 酪氨酸 - 苯丙氨酸 - 酰胺（GFSKLYFamide）和丝氨酸 - 甘氨酸 - 酪氨酸 - 丝氨酸 - 缬氨酸 - 亮氨酸 - 酪氨酸 - 苯丙氨酸 - 酰胺（SGYSVLYFamide）[迪亚兹 - 米兰达等人（1992年），《生物学通报》182:241 - 247]，是首次从海参中分离出的神经肽。利用抗GFSKLYFa的抗体，我们在此描述了GFSKLYFa样免疫反应性在光滑海参中的定位和分布模式，其中免疫反应性纤维形成了一个突出且广泛的肽能神经系统成分。在放射神经索的外神经和下神经部分以及消化、血液、呼吸和生殖系统、触手和管足中发现了表达GFSKLYFa样免疫反应性的神经元样细胞和神经纤维。在肠的粘膜层中发现了神经内分泌样细胞。超微结构免疫细胞化学分析显示，在肠浆膜层的神经细胞和纤维中，免疫反应性集中在囊泡中。免疫反应性神经纤维主要存在于覆盖肠平滑肌细胞并与其紧密接触的致密神经丛内。GFSKLYFa样免疫反应性在神经元或神经内分泌组织中的特异性表达以及一些纤维与肌肉细胞的紧密相邻表明，GFSKLYFa在光滑海参中充当神经肌肉递质或神经调节剂。GFSKLYFa样免疫反应性在海参整个神经系统中的广泛存在表明，GFSKLYFa在包括消化、呼吸、循环、生殖和运动在内的多种作用系统的控制中发挥着重要作用。
