Hideyuki Fujioka

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1. In monkey lingual artery strips partially contracted with prostaglandin F2alpha, acetylcholine-induced, concentration-related relaxations were abolished by removal of the endothelium. The response was not significantly influenced by indomethacin but attenuated by NG-nitro-L-arginine (L-NOARG); the effect of the nitric oxide (NO) synthase inhibitor was(More)
Isolated monkey cerebral arteries denuded of the endothelium responded to transmural electrical stimulation (5 Hz for 40 sec) with relaxations that are mediated by nitric oxide (NO) synthesized from L-arginine. The relaxant response was slightly inhibited by duroquinone, a superoxide anion-generating agent. The agent markedly inhibited the response after(More)
OBJECTIVE The present study was undertaken to examine whether arginine vasopressin (AVP) relaxes primate coronary artery and to analyse the mechanisms of its action in reference to endothelial nitric oxide and AVP receptor subtype. METHODS Isometrical tension responses to AVP and desmopressin were recorded in isolated monkey coronary arteries. RESULTS(More)
1. Responsiveness to EDRF-releasing substances and inhibitory nerve stimulation of canine isolated penile corpus cavernosum with and without saponin treatment were investigated. 2. Histological studies demonstrated that saponin did not detach endothelial cells from underlying tissues, but induced degenerative changes in the endothelial cells selectively. 3.(More)
The aqueous extract of the Panax ginseng (GE) potentiated the relaxation induced by transmural electrical stimulation or nicotine in monkey cerebral arterial strips denuded of the endothelium and partially contracted with prostaglandin F(2 alpha). The response to electrical stimulation was abolished by tetrodotoxin, whereas that to nicotine was suppressed(More)
We compared the mechanisms of vasorelaxation of acetylcholine and of substance P with reference to K+ channels, and analyzed pharmacologically the nature of endothelium-derived substance(s) other than NO and prostanoids in monkey and dog coronary arteries. Coronary arteries were isolated from monkeys and dogs, and the isometric tension of the artery strips(More)
The isolated rat mesenteric vasculature was perfused at constant pressures of 40, 80 or 120 mm Hg and the change in flow rate was measured. In the presence of phenylephrine, treatment with 3-[(3-cholamidopropyl) dimethylammonio]-1-propane sulfonate (CHAPS) or N(G)-nitro-L-arginine (L-NA) significantly inhibited the pressure-dependent flow rate increase, but(More)
The mechanisms underlying endothelium-dependent and nitric oxide (NO)/prostacyclin-independent, acetylcholine-induced relaxation in isolated canine corpus cavernosum were investigated. In isolated canine corpus cavernous strips treated with indomethacin (10–6 M) and N G-nitro-L-arginine (10–4 M), acetylcholine produced relaxations in a(More)
We investigated mechanisms of endothelium-dependent relaxation by acetylcholine resistant to indomethacin and N(G)-nitro-L-arginine and sensitive to cytochrome P-450 (CYP) inhibitors or charybdotoxin + apamin in the monkey lingual artery. Treatment with quinacrine, an inhibitor of phospholipase A2, abolished the relaxation by acetylcholine. However,(More)
In isolated canine cerebral and cutaneous arteries and duodenum, effects of neosurugatoxin (NSTX) on the response to nicotine were compared. Nicotine-induced relaxations are mediated by nitric oxide (NO) from vasodilator nerves in cerebral arteries and by calcitonin gene-related peptide (CGRP) in cutaneous arteries treated with NO synthase inhibitors.(More)