CALCITONIN-LIKE IMMUNOREACTIVITY IN THE SUBCOMMISSURAL ORGAN AND REISSNERS FIBER IN THE TELEOST CLARIAS-BATRACHUS, FROG RANA-TIGRINA AND LIZARD CALOTES-VERSICOLOR
N. Subhedar et al., CALCITONIN-LIKE IMMUNOREACTIVITY IN THE SUBCOMMISSURAL ORGAN AND REISSNERS FIBER IN THE TELEOST CLARIAS-BATRACHUS, FROG RANA-TIGRINA AND LIZARD CALOTES-VERSICOLOR, Brain research, 751(1), 1997, pp. 13-19
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 secr
etory substances has remained elusive. In the present study, immunocyt
ochemical application of polyclonal antibodies against calcitonin reve
aled intense immunoreactivity in the cells, cell processes and cerebro
spinal 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 e
xtended along the Sylvian aqueduct, fourth ventricle and central canal
of the spinal cord. Control procedures were employed to confirm the s
pecificity of the immunoreaction. The results for the first time sugge
st that calcitonin-like substance may be the synthetic and secretory p
roduct of the SCO that may be released into the CSF or stored in the R
F. 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 th
ese findings, it is felt that investigations aimed at establishing the
precise nature of calcitonin-like immunoreative material in the SCO-R
F complex may be rewarding. (C) 1997 Elsevier Science B.V.