Calcium binding protein calcyphosine in dog central astrocytes and ependymal cells and in peripheral neurons

Calcyphosine is a calcium binding protein discovered in the dog thyroid in 1979. Calcyphosine mRNA and immunoreactivity were detected using Western an d Northern blotting in the cerebral cortex, cerebral white matter and cereb ellum. Using immunohistochemistry and in situ hybridization, both are prese nt in ependymal cells, choroid plexus cells and several types of astrocytes of the subependymal cerebral layer, the cerebellar Bergmann layer, the ret inal ganglion cell layer, the optic nerve and the posterior pituitary. Both are also present in neurons of nasal olfactory mucosa, enteric Auerbach an d Meissner plexuses, orthosympathic and spinal cord ganglia as well as in e ndocrine cells of neural crest origin in the adrenal medulla. Calcyphosine immunoreactive astrocytes were also present mainly in hemispheric cerebral gray and white matter, hemispheric subcortical structures, brain stem and s pinal cord. These results show that calcyphosine is a characteristic calciu m binding protein of astrocytes and ependymal cells in the central nervous system and of neurons in the peripheral nervous system. This is of interest in view of the importance of calcium regulation in these cells, and since calcyphosine a calcium binding protein phosphorylated by cAMP dependent pro cess, may be an intermediate between cAMP and inositol phosphate cascades. (C)1998 Elsevier Science B.V. All rights reserved.