Tsutomu Nakahara

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Increasing evidence suggests that the complex interactions among multiple cell types including neuronal, glial, and vascular cells, are critical for maintaining adequate cerebral blood flow that is necessary for normal brain function and survival. The disturbance of these interactions contributes to the pathogenesis of central nervous system disorders such(More)
Prostaglandin E(2) (PGE(2)) plays an important role in promoting inflammation and neurological disorders. The actions of PGE(2) are mediated by four different G-protein-coupled receptors (EP(1), EP(2), EP(3), and EP(4)). The purpose of this study was to determine whether stimulation of prostanoid EP(2) receptors has the potential to prevent the excitotoxic(More)
Retinal ischemia-reperfusion causes capillary degeneration but the mechanisms of damage are not well understood. The NMDA receptor plays an important role in neuronal damage after ischemia-reperfusion. Therefore, we determined whether retinal blood vessels are damaged structurally and functionally in a rat model of retinal degeneration induced by NMDA. At 7(More)
We have previously reported that β3-adrenoceptor agonists dilate retinal blood vessels, but their effects on retinal neurons have been unclear. In this study, we examined the action of the β3-adrenoceptor agonist CL316243 against retinal damage induced by intravitreal injection of N-methyl-D-aspartate (NMDA) in rats. CL316243 was injected into the vitreous(More)
It has been suggested that nitric oxide (NO) stimulates the cyclooxygenase (COX)-dependent mechanisms in the ocular vasculature; however, the importance of the pathway in regulating retinal circulation in vivo remains to be elucidated. Therefore, we investigated the role of COX-dependent mechanisms in NO-induced vasodilation of retinal blood vessels in(More)
Although hydrogen sulfide (H2S) is generally thought to be a toxic gas, it has been reported to protect various tissues against ischemia-reperfusion injury. In the present study, we histologically investigated whether H2S, using sodium hydrosulfide (NaHS) as its donor, had a protective effect on N-methyl-d-aspartate (NMDA)-induced retinal injury in the rat(More)
Although a blockade of acetylcholine esterase has been reported to suppress neuronal cell death induced by exogenous glutamate and beta-amyloid, information is still limited regarding the neuroprotective effects of the acetylcholine esterase inhibitor donepezil. We histologically examined the effects of donepezil on neuronal injury induced by(More)
Although a blockade or lack of N-type Ca(2+) channels has been reported to suppress neuronal injury induced by ischemia-reperfusion in several animal models, information is still limited regarding the neuroprotective effects of a dual L/N-type Ca(2+) channel blocker, cilnidipine. We histologically examined the effects of cilnidipine on neuronal injury(More)
Brief ischemia was reported to protect various cells against injury induced by subsequent ischemia-reperfusion, and this phenomenon is known as ischemic preconditioning. The aims of the present study were to clarify whether early ischemic preconditioning could be observed in the rat retina by histological examination. Male Sprague-Dawley rats were subjected(More)
Although the characteristics of the static interactions between the sympathetic and parasympathetic nervous systems in regulating heart rate have been well established, how the dynamic interaction modulates the heart rate response remains unknown. Thus, we investigated the dynamic interaction by estimating the transfer function from nerve stimulation to(More)