Sadahiro Iwabuchi

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Glutamate (Glu) is a major excitatory neurotransmitter of the mammalian central nervous system and under normal conditions plays an important role in information processing in the brain. Therefore, extracellular Glu is subject to strong homeostasis. Astrocytes in the brain have been considered to be mainly responsible for the clearance of extracellular Glu.(More)
We have studied the effects of neomycin, a potent inhibitor of inositol phospholipid-specific phospholipase C (PLC), on the germination of rice seed and the gibberellin-induced expression of alpha-amylase in the aleurone layer and the scutellar tissues. It was shown that, in the absence of exogenous Ca2+, neomycin markedly reduced the germination speed and(More)
The opening of pannexin-1 (Px1) hemichannels is regulated by the activity of P2X(7) receptors (P2X(7)Rs). At present, however, little is known about how extracellular ATP-sensitive P2X(7)Rs regulates the opening and closure of Px1 hemichannels. Several lines of evidence suggest that P2X(7)Rs are activated under pathological conditions such as ischemia,(More)
Glucose is a necessary source of energy to sustain cell activities and homeostasis in the brain, and enhanced glucose transporter (GLUT) activities are protective of cells during energy depletion including brain ischemia. Here we investigated whether and if so how the astrocytic expression of GLUTs crucial for the uptake of glucose changes in ischemic(More)
Application of a brief period of ischemia, i.e. preconditioning treatment of the middle cerebral artery territory, has been known to produce ischemic tolerance, reducing cerebral infarction volume in the penumbra region after lethal ischemia. However, little is known about the molecular mechanisms responsible for preconditioning-induced ischemic tolerance.(More)
Waves of elevated intracellular free calcium that propagate between neighboring astrocytes are important for the intercellular communication between astrocytes as well as between neurons and astrocytes. However, the mechanisms responsible for the initiation and propagation of astrocytic calcium waves remain unclear. In this study, intercellular calcium(More)
Magnesium ions (Mg(2+)) play a fundamental role in cellular function, but the cellular dynamic changes of intracellular Mg(2+) remain poorly delineated. The present study aims to clarify whether the concentration of intracellular Mg(2+) possibly changes cyclically in association with rhythmic contraction and intracellular Ca(2+) oscillation in cultured(More)
A brief period of ischemia, i.e. preconditioning of the middle cerebral artery territory, induces ischemic tolerance reducing the cerebral infarction volume caused by subsequent lethal ischemia. Nevertheless, little is known about the molecular mechanisms underlying this phenomenon. In the present study, we examined the involvement of the activation of Akt,(More)
Constant mechanical stress is essential for the maintenance of bone mass and strength, which is achieved through the cooperative functions of osteoblasts and osteoclasts. However, it has not been fully elucidated how these cell types mediate mechanical signals. Low-intensity pulsed ultrasound (LIPUS) therapy is a recently developed method for application of(More)
TorsinA is an evolutionarily conserved AAA+ ATPase, and human patients with an in-frame deletion of a single glutamate (ΔE) codon from the encoding gene suffer from autosomal-dominant, early-onset generalized DYT1 dystonia. Although only 30-40% of carriers of the mutation show overt motor symptoms, most experience enhanced excitability of the central(More)