Toshimitsu Uchiyama

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The facial vein in several species has been shown to have unusual properties, including exhibition of spontaneous myogenic tone and relaxation to norepinephrine (NE). The present study was undertaken to characterize the relaxant effect of 5-hydroxytryptamine (5-HT) on the rabbit facial vein. An isolated ring preparation of the rabbit facial vein exhibited(More)
The parasympathetic nervous system is responsible for maintaining normal intestinal and bladder function, contracting the smooth muscle by releasing the neurotransmitters acetylcholine (ACh) and ATP and relaxing sphincters by releasing nitric oxide. ACh is the main transmitter released and smooth muscle contraction is mediated via a mixed M2/M3 receptor(More)
The effect of kanamycin (Kn) on evoked transmitter release was examined in frog end-plates in vitro. By a presynaptic action, Kn (0.02 to 1 mM) significantly reduced the amount of acetylcholine liberated by nerve stimulation. In addition to its presynaptic effects, Kn (0.96 mM) decreased the size of the miniature end-plate potentials possibly by acting at(More)
Cisplatin (4 mg/kg, i.v.) induced both early emesis, which appears within the first 8-h period, and delayed emesis, which appears between 8 and 48 h after its administration to pigeons. GR205171 ([(2S-cis)-N-((2-methoxy-5(5-(trifluoromethyl)-1H-tetrazol-1-yl)-phenyl) methyl)-2-phenyl-3-piperidinamine dihydrochloride]) administered intramuscularly (1-10(More)
The present study examined the role of the noradrenergic system in the modulation of acetylcholine (ACh) release in the rostral ventrolateral medulla (RVLM) using in vivo microdialysis of morphine. The basal level of ACh was 325.0 +/- 21.1 fmol/20 microl/15 min in the presence of neostigmine (10 microM). Intraperitoneal (i.p.) administration of 5 and 10(More)
We investigated the ability of dexamethasone to attenuate cisplatin (4 mg/kg, i.v.)-induced early and delayed emesis. These appear within the first 8-h period (early phase) and between 8 and 48 h (delayed phase), respectively, after cisplatin administration in the pigeon. Dexamethasone (0.1 and 1 mg/kg, i.m.) reduced significantly the number of emetic(More)
Cernitin pollen extract (CN-009), extract from several pollen species, has been used for urinary dysfunction. As its mode of action has not been clarified, we investigated the action of CN-009 on the isolated bladder smooth muscles of rats, guinea pigs and cats and the intravesical pressure in female rats. CN-009 contracted isolated detrusor muscles of(More)
In the curarized preparation, 3,4-diaminopyridine (3,4-DAP) and 4-aminopyridine (4-AP) were equiactive in their ability to antagonize d-tubocurarine caused complete depression of the indirectly elicited twitches of the sciatic nerve-tibialis anterior muscle preparation in anesthetized rats. In the non-curarized preparation, 3,4-DAP showed 2.3 to 4.0 times(More)
We investigated the effects of several autonomic nervous system-related agents on the intravesical pressure (IVP) in adult (11-23 weeks old, 200-350 g) and aged (2 years old, 350-770 g) female rats. Acetylcholine induced a dose-dependent and transient increase of IVP, which was competitively antagonized by pirenzepine weakly and by atropine strongly. These(More)
Antagonistic actions of 4-aminopyridine (4-AP) and neostigmine methylsulfate (NSG) on the neuromuscular and cardiovascular depressions by kanamycin (KM) were studied in urethane anesthetized rats, in comparison with D-tubocurarine (D-Tc). Measured parameters were indirectly elicited twitch of tibialis anterior muscle, mean arterial pressure and heart rate.(More)