Yasuhiro Tsunoda

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CCK(A) receptors are present on vagal afferent fibers. The objectives of this study were to identify the presence of high- and low-affinity CCK(A) receptors on nodose ganglia and to characterize the intracellular calcium signal transduction activated by CCK. Stimulation of acutely isolated nodose ganglion cells from rats with 1 nM CCK-8 primarily evoked a(More)
Entry of extracellular calcium (Ca++) via voltage-gated Ca++ channels is essential for neurotransmitter release. In this study, we examined whether nicotinic receptor-stimulated release of acetylcholine (ACh) and somatostatin (S14) are coupled to calcium influx via distinct calcium channel subtypes in the myenteric plexus. Isolated ganglia from the guinea(More)
Adenosine 3',5'-cyclic monophosphate (cAMP) is an important second messenger involved in cholinergic transmission. The aims of this study were to characterize the calcium channels associated with cyclic AMP-mediated acetylcholine release and Ca++ efflux in ileal myenteric plexus. We also examined if this process can be inhibited by agents such as opioids(More)
Intracellular distribution of cytoplasm-free Ca2+ concentrations ((Ca2+)i) and dynamic changes during stimulation of viable hair cells were studied using digital imaging microscopy and the Ca2(+)-sensitive dye fura-2. (Ca2+)i was visualized on pseudo-colour images and three-dimensional computer graphics. In the resting state, the intra-cellular distribution(More)
Ca2+ influx from the extracellular space in nonexcitable cells occurs via receptor-operated and refilling processes. However, they showed different characteristics with respect to the Mn2+ permeability, depletion of intracellular Ca2+ stores, and sensitivity to the K+ ionophore valinomycin in rat pancreatic acinar cells. While Mn2+ did not enter into the(More)
The characteristics underlying cytosolic free calcium oscillation were evaluated by superfused dual wave-length microspectrofluorometry of fura-2-loaded single acinar cells from rat pancreas. Application of a physiological concentration of cholecystokinin octapeptide (CCK) (20 pM) induced a small basal increase in cytosolic free calcium concentration(More)
Fetal and neonatal hypoxia is suggested as a noticeable risk factor related to the occurrence of subependymal hemorrhages. To investigate the cause of newborn subependymal hemorrhages, a 0 day old newborn rabbit was exposed to either 5 or 10 minutes hypoxia by N2 box. After exposure, the brain was observed by optical and electric microscope using(More)
Spatial and temporal changes of cytoplasmic free calcium concentration ([Ca2+]i) in single parietal cells of guinea pig were investigated with a digital imaging microscope equipped with a microspectrofluorometer, using a Ca2+-sensitive dye, fura-2. Intracellular distribution of [Ca2+]i was not homogeneous, but there were two kinds of [Ca2+]i gradient in the(More)
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