A Morphological and Functional Study of Choroidal Melanocytes

脉络膜黑素细胞的形态和功能研究

基本信息

批准号：
63440066
负责人：
TOKORO Takashi
金额：
$ 10.18万
依托单位：
Tokyo Medical and Dental University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (A)
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1991
项目状态：
已结题

项目摘要

This study was performed to clarify the morphology and function of the choroidal melanocytes. Eyes of macaque monkeys, pigmented rabbits and cats were used for the morphological study. In the suprachoroidea, the fibroblasts had long thin cytoplasmic processes and were in contact with neighboring cells by intercellular junctions, thus forming a network.Melanocytes were wedged between the thin processes of fibroblasts, and surrounded by collagen fibers and elastic fibers. In some areas, there were interfibroblastic spaces, which were devoid of fiber elements and filled with amorphous substances. When the tracers such as a suspension of activated carbon were injected into the anterior chamber, these tracers were detected in the interfibroblastic spaces at the suprachoroid. So, these spaces may function as the lymphatic route. Furthermore, we examined VIP-positive nerve fiber in the choroid of human enucleated eye by electron microscopical immunohistochemstry. Although VIP-positive nerve fibers were observed in the suprachoroid and inner scleral layers near choroidal melanocytes, no direct contact between VIP-positive nerve fibers and melanocytes could be found.In addition, electron microscopy revealed the gap junction between choroidal melanocytes and physiological methods demonstrated dye coupling and electrical coupling between choroidal melanocytes in rabbit's eyes. Thus it can be hypothesized that a group of choroidal melanocytes may function as a unit by exchanging ions and bioactive substances through their intercellular communication system, the gap junction. Furthermore, we investigated the suprachoroid uptake of extracellular calcium ions by using fura-2 and found that the intercellular calcium ions concentration was significantly increased by ATP superfusion. So, one of the functions of melanocytes and fibroblasts may be to regulate the extracellular fluid in the choroid.

进行这项研究是为了阐明脉络膜黑素细胞的形态和功能。使用猕猴、色素兔和猫的眼睛进行形态学研究。在脉络膜上层，成纤维细胞具有长而细的胞质突起，通过细胞间连接与邻近细胞接触，从而形成网状。黑素细胞楔入成纤维细胞的细突起之间，周围被胶原纤维和弹力纤维包围。在某些区域，存在纤维母细胞间空间，其中缺乏纤维元素并充满无定形物质。当将活性炭悬浮液等示踪剂注入前房时，在脉络膜上层的成纤维细胞间隙中检测到这些示踪剂。因此，这些空间可能起到淋巴路线的作用。此外，我们通过电子显微镜免疫组织化学检查了人摘除眼脉络膜中的 VIP 阳性神经纤维。虽然在靠近脉络膜黑素细胞的脉络膜上层和巩膜内层观察到VIP阳性神经纤维，但未发现VIP阳性神经纤维与黑素细胞之间的直接接触。此外，电镜显示脉络膜黑素细胞之间存在间隙连接，生理学方法证明兔眼脉络膜黑素细胞之间的染料耦合和电耦合。因此，可以假设一组脉络膜黑素细胞可能作为一个整体通过细胞间通讯系统间隙连接交换离子和生物活性物质来发挥作用。此外，我们使用fura-2研究了脉络膜上层对细胞外钙离子的摄取，发现ATP灌注显着增加了细胞间钙离子浓度。因此，黑素细胞和成纤维细胞的功能之一可能是调节脉络膜中的细胞外液。