Kazuhiro Takazawa

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The contents of parvalbumin in various nervous tissues of the rat were measured by radioimmunoassay (RIA) and its cellular distribution was immunohistochemically examined by peroxidase-antiperoxidase methods. The antibody, raised in rabbits using rat skeletal muscle parvalbumin, did not cross-react with other Ca2+-binding proteins such as calmodulin or(More)
The distribution of inositol 1,4,5-trisphosphate (InsP3) 3-kinase mRNA in the rat brain is reported using oligonucleotides based on a cDNA clone sequence that encodes rat brain InsP3 3-kinase and the in situ hybridization technique. Moderate levels were found in CA2-4 pyramidal neurons, in the cortex, and in the striatum. The cerebellar granule cells,(More)
Inositol 1,4,5-trisphosphate (Ins P3) 3-kinase catalyzes the ATP-dependent phosphorylation of Ins P3 to Inositol 1,3,4,5-tetrakisphosphate (Ins P4). Ca2+/calmodulin (CaM)-sensitivity of Ins P3 3-kinase was measured in the crude soluble fraction from rat brain and different anatomic regions of bovine brain. Kinase activity was inhibited in the presence of(More)
Inositol 1,4,5-trisphosphate (InsP3) 3-kinase catalyses the ATP-dependent phosphorylation of InsP3 to inositol 1,3,4,5-tetrakisphosphate (InsP4). InsP3 3-kinase was purified from rat brain by Blue-Sepharose, phosphocellulose and calmodulin (CaM)-Sepharose affinity chromatography. The purified enzyme was stimulated by Ca2+/CaM by 3-6-fold as compared with(More)
As a result of its interaction with a specific receptor, inositol 1,4,5-trisphosphate mobilizes intracellular calcium. The metabolism of inositol 1,4,5-trisphosphate is rather complex: inositol 1,4,5-trisphosphate 3-kinase produces inositol 1,3,4,5-tetrakisphosphate, a putative second messenger. In order to elucidate inositol 1,3,4,5-tetrakisphosphate(More)
Inositol 1,4,5-trisphosphate 3-kinase (InsP3 3-kinase) plays a crucial role in calcium homeostasis by regulating InsP3 levels. We have reported the highest concentrations of InsP3 3-kinase in the dendrites of cerebellar Purkinje cells and hippocampal pyramidal cells of the CA1 sector of the Ammon's horn. We here investigate its subcellular localization by(More)
We have investigated the regional difference of neuronal vulnerability within the hippocampus in the C57BL/6 strain mice after forebrain ischemia. Both common carotid arteries of fifty mice were occluded for 12 min and the mouse brain was examined with cresyl violet staining. The CA4 sector was found to be the most vulnerable within the hippocampus. The CA2(More)
The distribution of inositol 1,4,5-trisphosphate (InsP3) 3-kinase was studied in the adult rat brain, using polyclonal antibodies raised against the purified 50,000-Da rat brain enzyme by immunohistochemistry and Western blot, in addition to enzymatic assay. Immunohistochemically, the enzyme was detected in neurons, where it was localized in the dendrites(More)
Visit-to-visit blood pressure (BP) variability is an important predictor of stroke. However, which antihypertensive drug combination is better at reducing visit-to-visit BP variability and therefore at reducing stroke incidence remains uncertain. We have previously reported that the dihydropyridine calcium channel blocker benidipine combined with a(More)