Subhedar N, Khan F A, Jain M R
Department of Pharmaceutical Sciences, Nagpur University, India.
Brain Res. 1997 Mar 14;751(1):13-9. doi: 10.1016/s0006-8993(96)01172-9.
In the CNS of vertebrates, although the subcommissural organ (SCO) has been identified as an ependymal brain gland and Reissner's fiber (RF) as a condensed product of its secretion, the exact nature of the secretory substances has remained elusive. In the present study, immunocytochemical application of polyclonal antibodies against calcitonin revealed intense immunoreactivity in the cells, cell processes and cerebrospinal spinal fluid (CSF)-contacting apical terminals of the columnar ependymal cells of the SCO in the teleost, Clarias batrachus. Intense immunoreactivity was also seen throughout the length of the RF as it extended along the Sylvian aqueduct, fourth ventricle and central canal of the spinal cord. Control procedures were employed to confirm the specificity of the immunoreaction. The results for the first time suggest that calcitonin-like substance may be the synthetic and secretory product of the SCO that may be released into the CSF or stored in the RF. Presence of calcitonin-like immunoreactivity in the SCO-RF complex of the frog Rana tigrina and the lizard Calotes versicolor underscores wider significance of the phenomenon. In view of the potentials of these findings, it is felt that investigations aimed at establishing the precise nature of calcitonin-like immunoreactive material in the SCO-RF complex may be rewarding.
在脊椎动物的中枢神经系统中，尽管已确定室管膜下器官（SCO）为室管膜脑腺，瑞氏纤维（RF）为其分泌的浓缩产物，但分泌物质的确切性质仍不清楚。在本研究中，应用抗降钙素多克隆抗体进行免疫细胞化学检测发现，在鲶鱼（Clarias batrachus）的SCO柱状室管膜细胞、细胞突起及与脑脊液（CSF）接触的顶端终末中，有强烈的免疫反应性。在沿中脑导水管、第四脑室和脊髓中央管延伸的RF全长中也可见强烈的免疫反应性。采用对照实验来证实免疫反应的特异性。结果首次表明，降钙素样物质可能是SCO的合成和分泌产物，可能释放到脑脊液中或储存在RF中。在虎纹蛙（Rana tigrina）和变色树蜥（Calotes versicolor）的SCO-RF复合体中存在降钙素样免疫反应性，突出了这一现象更广泛的意义。鉴于这些发现的潜在价值，认为旨在确定SCO-RF复合体中降钙素样免疫反应性物质确切性质的研究可能会有所收获。
