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

海藻的神经腺细胞大多是双核的，双核细胞似乎在背上皮的有限区域内增殖。在观察到的所有孤生海鞘物种中，海藻的神经腺中都观察到了双核细胞。 H. aurantium。在 H. hilgendorfi f. Cnemidocarpa 和 verrucosa，somo 细胞有两个细胞核。在其他物种中没有发现双核细胞。双核细胞的出现可能与适应寒冷的海水环境有关。免疫组化观察显示，哺乳动物LHRH在神经节中呈阳性反应，而在神经腺中则无反应。相比之下，仅鲢鱼GTH在神经腺中观察到阳性反应。这些阳性反应通过重吸收试验得到证实。结果表明，海鞘的神经节和神经腺可能是脊椎动物下丘脑和垂体的同源物。其他抗皮图激素的抗体； GH、PRL、LH、FSH、ACTH 和 MSH 在神经节或神经腺中均无反应。此外，在神经节和腺体中均未观察到胰岛素、胰高血糖素和促胰液素。这与pestarino (1984和1985)的结果相矛盾，需要进一步研究。 β-内啡肽抗体在神经腺或背链中产生阳性反应。在神经节或背链中观察到甲硫脑啡肽。神经节和腺体中的免疫反应性是通过 P 物质的抗体获得的。这些物质存在的意义需要进一步检查。在神经节中获得两栖动物 PRL 免疫反应阳性。然而，在SDS聚丙烯酰胺凝胶电泳显色后，通过免疫印迹法进行抗两栖动物PRL的免疫反应，无法生化检测到PRL的存在。神经节样本中似乎含量很少。根据神经复合体超微结构研究的复查，在神经细胞及其撒细胞中均观察到致密的分泌颗粒。此外，背链细胞也有许多致密颗粒。神经腺双核细胞中未观察到分泌颗粒，但有许多空泡。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垂体的同源体。较少的

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