Hiroki Kushida

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The effect of verapamil on the decrease in renal blood flow (RBF) induced by angiotensin II (Ang II), norepinephrine (NE) or renal nerve stimulation (RNS) was examined in pentobarbital-anesthetized dogs. The injection into the renal artery of Ang II (0.01-0.1 micrograms), or NE (0.1-1.0 micrograms), or RNS (1-10 Hz) decreased RBF in a dose- or(More)
The phorbol ester 12-O-tetradecanoyl phorbol-13-acetate (TPA) was used to examine the hypothesis that phosphoinositide turnover is involved in the regulation of myocardial contractility mediated by stimulation of alpha-adrenoceptors in the mammalian cardiac muscle. Exposure of the isolated rabbit papillary muscle electrically driven at a rate of 1 Hz at a(More)
[3H]Prazosin bound with high affinity to the membrane fraction derived from the rabbit ventricular myocardium. Oxymetazoline displaced [3H]prazosin from its binding site, did not elicit a positive inotropic effect but antagonized the positive inotropic effect of phenylephrine mediated by alpha-adrenoceptors in the presence of a beta-antagonist. Naphazoline(More)
60 GHz millimeter-wave wireless LAN (WLAN) has been attracting much interest of industry because of its very high capacity. However, it needs many antennas to cover a wide space on account of the strong atmospheric extinction and directivity of 60 GHz RF signal. If an access point (AP) is deployed for each of many antennas in a 60 GHz WLAN, the total cost(More)
Experiments were carried out to elucidate the mechanism that the positive inotropic effect mediated by alpha 1-adrenoceptors is more susceptible to organic calcium antagonists than the beta-adrenoceptor-mediated effect. Verapamil and diltiazem displaced the specific binding of [3H]prazosin to the membrane fraction derived from the rabbit ventricular(More)
Experiments were carried out to characterize the pharmacological properties of enantiomers and racemic mixture of dobutamine to modulate the myocardial contractility through alpha and beta adrenoceptors in the rabbit papillary muscle. Dobutamine caused the concentration-dependent positive inotropic effect: the rank order of potency was R-(+)- greater than(More)
Experiments were carried out to characterize the adenosine-induced negative inotropic effect in relation to the extent of beta-adrenoceptor activation in the isolated dog left ventricular myocardium. Adenosine and R-N6-phenylisopropyladenosine inhibited the positive inotropic effect of isoprenaline (10(-7) mol/l and lower) about 20% of its maximal response,(More)
[3H]prazosin bound to the membrane fraction derived from the ferret ventricular muscle with high affinity in a saturable manner (Kd = 0.25 nmol/l and Bmax = 27 fmol/mg protein in the right ventricle). [3H]CGP-12177, a beta-adrenoceptor ligand, bound to the membrane fraction with a Kd value of 0.29 nmol/l and a Bmax of 42 fmol/mg protein. In the isolated(More)
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