Takayuki Kamiya

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A series of comb-type copolymers comprised of various polycation backbones and dextran (Dex) side chains were prepared to study the DNA/copolymer interaction. While the cationic copolymers with a lower degree of dextran grafts maintained an ability to condense DNA molecules into a globule form those with a higher degree of dextran grafting interacted with(More)
PURPOSE Cilostazol, a selective inhibitor of phosphodiesterase 3, has antiplatelet aggregation and peripheral vasodilation effects. We examined the effects of cilostazol on the retinal microvascular diameter to determine its dependence on the endothelium and/or smooth muscle to reveal the signaling mechanisms involved in this vasomotor activity. METHODS(More)
PURPOSE Prostacyclin (PGI2) is usually described as an endoEDRFsthelium-derived relaxing factor, but the vasoreactivity to PGI2 in the retinal arterioles and the underlying mechanisms are not fully understood. We examined the effects of PGI2 on the retinal microcirculation using beraprost sodium (BPS), a stable PGI2 analogue, and the signaling mechanisms(More)
Although sphingosine 1-phosphate (S1P), a bioactive lipid derived from activated platelets, has a variety of physiologic effects on vessels, no reports have described the effect of S1P on the retinal circulation. We examined the effect and underlying mechanism of the vasomotor action of S1P on porcine retinal arterioles. The porcine retinal arterioles were(More)
PURPOSE Although recent clinical trials have demonstrated that fenofibrate is effective for treating diabetic retinopathy, the mechanism of this beneficial effect remains unclear. In the current study, we examined the effect of the vasomotor action of fenofibrate on porcine retinal arterioles. METHODS Porcine retinal arterioles (internal diameter, 60-90(More)
PURPOSE Although endothelium-dependent nitric oxide (NO)-mediated dilation of retinal arterioles has been well described, the role of endothelium-derived hyperpolarizing factor (EDHF) in the retinal arteriolar response remains unclear. In the current study, we examined the contribution of EDHF to the retinal arteriolar dilation to the inflammatory agent(More)
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