Tsutomu Nakahara

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Inhibitors of VEGF signaling can block angiogenesis and reduce tumor vascularity, but little is known about the reversibility of these changes after treatment ends. In the present study, regrowth of blood vessels in spontaneous RIP-Tag2 tumors and implanted Lewis lung carcinomas in mice was assessed after inhibition of VEGF receptor signaling by AG-013736(More)
The aim of this study was to examine whether stimulation of β3-adrenoceptors dilates rat retinal blood vessels and how diabetes affects the vasodilator responses. Images of ocular fundus were captured with an original high-resolution digital fundus camera in vivo. The retinal vascular responses were evaluated by measuring diameter of retinal blood vessels(More)
The role of protease-activated receptor-2 (PAR-2) in the regulation of the rat urinary bladder contractility was investigated. Both trypsin and PAR-2 activating peptide (SLIGRL-NH2) produced a concentration-dependent contractile response in the urinary bladder preparations. These contractions were abolished by removal of the urinary bladder mucosa and were(More)
The relaxant effect of procainamide, a class Ia antiarrhythmic agent, was examined in bovine tracheal smooth muscle. Procainamide produced concentration-dependent decreases in tension and full relaxation in the preparations contracted with methacholine (0.3 microM). By comparison, in preparations contracted with 40 mM K(+), procainamide had only slight(More)
Antibodies and other macromolecular therapeutics can gain access to tumor cells via leaky tumor vessels. Inhibition of vascular endothelial growth factor (VEGF) signaling can reduce the vascularity of tumors and leakiness of surviving vessels, but little is known about how these changes affect the distribution of antibodies within tumors. We addressed this(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)
We examined the inhibitory mechanism of BRL37344, a β-adrenoceptor agonist that is considered to be specific to β3-subtype, on muscarinic receptor-mediated contraction of the rat urinary bladder smooth muscle. BRL37344 produced apparently biphasic concentration-relaxation curves in the urinary bladder smooth muscle contracted with carbachol (0.6 µM). The(More)
Possible involvement of Ca2+-independent phospholipase A2 (iPLA2) was examined in protease-activated receptor-2 (PAR-2)-mediated contraction of the rat urinary bladder. Both PAR-2 activating peptide (PAR-2 AP; SLIGRL-NH2) and trypsin produced a concentration-dependent contractile response in the urinary bladder preparations. These contractions were(More)
We examined the effects of vasodilatory prostaglandins (prostacyclin and prostaglandin E(2)) and selective agonists for prostanoid EP(2) and EP(4) receptor on the diameters of retinal blood vessels and fundus (retinal/choroidal) blood flow in rats. Male Wistar rats (8- to 10-week-old) were treated with tetrodotoxin (50 microg/kg, i.v.) to eliminate any(More)
Protease-activated receptor-2 (PAR-2) is activated by serine proteases, such as trypsin and mast cell tryptase. Recently, we have shown that activators of PAR-2 contract the rat urinary bladder mainly by stimulating release of prostaglandins (PGs) from the mucosal layer. In the present study, we investigated how the PAR-2-mediated responses are altered in(More)