"Evolution of pituitary, Comparative Endocrinological Study on Neural Gland of Ascidian"

罗氏梭子蟹的神经腺细胞多为双核细胞，在背上皮的有限区域内可见双核细胞的增殖。金黄杆菌属。在节果树和疣中，SOMO细胞有两个核。在其他物种中未发现双核细胞。从免疫组织化学观察，哺乳动物LHRH在神经节呈阳性反应，而在神经腺中未见阳性反应。相反，在神经腺中只观察到了鲤鱼GTH的阳性反应。重吸收试验证实了这些阳性反应。结果表明，海鞘的神经节和腺体可能是脊椎动物下丘脑和垂体的同源物。其他抗Pitu…抗体生长激素、催乳素、黄体生成素、卵泡刺激素、促肾上腺皮质激素和促肾上腺皮质激素在神经节和神经腺均无反应。此外，在神经节和腺体中均未观察到胰岛素、胰升糖素和促胰液素。这与Pestarino(1984和1985)的结果相矛盾，这需要进一步的研究。抗β-内啡肽抗体在神经腺和背束均呈阳性反应。甲硫氨酸脑啡肽在神经节和背束均可见。神经节和腺体均可用P物质抗体进行免疫反应，这些物质的存在意义有待进一步检验。两栖动物PRL在神经节内呈阳性反应。然而，用SDS-聚丙烯酰胺凝胶电泳法建立的抗两栖类催乳素免疫反应免疫印迹法不能生化检测到PRL的存在。神经复合体的超微结构研究表明，神经细胞及其撒克逊细胞内均有致密的分泌颗粒。此外，背束的细胞也有许多致密的颗粒。神经腺双核细胞内未见分泌颗粒，但有大量空泡。因此，这些细胞可能具有分泌功能。因此，海鞘的神经腺仍然有可能是脊椎动物脑垂体的同源物。较少

Most of the cells of the neural gland in Halocynthia roretzi are binucleate and the binucleate cells seem to proliferate in the limited area of the dorsal epithelium.In ll species of solitary ascidians observed, the binucleate cells were observed in the neural glands of Halocynthia and. H. aurantium. In H. hilgendorfi f. Cnemidocarpa and verrucosa, somo cells have two nuclei. No binucleate cells were found in other species. The occurrence of binucleate cells may be associated with adaptation to a cold, sea-water environment.From the immunohistochemical observations, the positive reaction for mammalian LHRH was observed in the neural ganglion but no reaction in the neural gland. In contrast, positive reaction for only silver-carp GTH was observed in the neural gland. These positive reactions were confirmed with reabsorption test. The results suggest that the neural ganglion and gland of ascidians may be the homologue of the vertebrate hypothalamus and pituitary. Other antibodies to pitu … More itary hormones; GH, PRL, LH, FSH, ACTH and MSH gave no reaction in either the neural ganglion or the neural gland. Moreover, insulin, glucagon and secretin were not observed in both the neural ganglion and gland. This is contradictory to the results of pestarino (1984 and 1985), and this requires further study. Antibody to beta-endorphin gave positive reaction in either the neural gland or the dorsal strand. Met-enkephalin was observed in either the ganglion or the dorsal strand. Immunoreactivity both in the ganglion and gland was obtained with antibody to substance P. The significance of the existence of these substances requires further examination. Immunoreaction positive for amphibian PRL was obtained in the neural ganglion. However, the presence of PRL can not detected biochemically using the immunoreaction for anti-amphibian PRL by western blot method after development with SDS polyacrylamide gel electrophoresis. It seems to be very small contents of it in the sample from the neural ganglion.According to the re-examinations of ultra-structural studies on the neural complex, the dense secretory granules were observed both in the neural cells and their saxons. Moreover, the cells of dorsal strand also have many dense granules. No secretory granules were observed in the binucleate cells of the neural gland, but they have many vacuoles. Therefore, these cells may have a secretory function.Thus, the neural gland of ascidian still remains the possibility to be homologue of the vertebrate pituitary. Less