고양이 뇌에서의 Inositol 1,4,5-trisphosphate 3-kinase 분포에 관한 면역조직화학적 연구

초록

Inositol 1,4,5-trisphosphate 3-kinase (IP3K) phosphorylates Inositol 1,4,5-trisphosphate (InsP3) to produce inositol 1,3,4,5-tetrakisphosphate (InsP4) through agonist stimulation. InsP4, is emerging as a second messenger which controls Ca2+ homeostasis or regulates InsP4-mediated K+ channel. Although the role of InsP4 is not yet clearly understood and its receptor protein has not been clearly identified, InsP3 and InsP4 and their receptors may have a significant role in Ca2+-induced intracellular signal transduction mechanism. This study was attempted to investigate the IP3K distribution in the cat brain by immunohistochemical study using monoclonal antibodies against IP3K. The IP3K immunoreactivity was found in the neurons of the cerebral cortex, hippocampus, and cerebellum which were well known as the area of high synaptic plasticity. The highest immunoreactivity was observed in the perikarya and dendritic tree of Purkinje cells in the cerebellum, polymorphic cells in the CA4 area of hippocampus, neurons in lateral dorsal septal nucleus, and caudate-putamen. Moderate high immunoreactivity was found in the perikarya and dendritic field of pyramidal neurons in the cerebral cortex, pyramidal neurons of the CA1 to CA3 areas of hippocampus, subiculum, and low immunoreactivity was found in the granule cells of dentate gyrus, amygdaloid nucleus, indusium grisium. The reactivity of cerebellar granule cells, deep cerebellar nuclei, thalamus, hypothalamus, brain stem, and white matter tracts was almost negative. There was no obvious immunoreactivity in glial cells and endothelial cells. This finding may suggest a specialized role for IP3K in the brain.

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