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Biomedical subjects

K Honda

Publications and source records attributed to K Honda.

At least 613 records · Page 34Linked to original sources
PubMed1986

Adrenoceptor blocking properties of the stereoisomers of amosulalol (YM-09538) and the corresponding desoxy derivative (YM-11133).

The antagonist potencies of amosulalol (YM-09538), its stereoisomers and the corresponding desoxy derivative (YM-11133) have been compared at alpha-1, alpha-2, beta-1 and beta-2 adrenoceptors in isolated organs in vitro and in radioligand binding experiments. In isolated peripheral tissues, (+/-)-, (-)- and (+)-amosulalol and YM-11133 are selective alpha-1 adrenoceptor antagonists over alpha-2 adrenoceptors by two orders of magnitude and are nonselective beta adrenoceptor antagonists. (+)-Amosulalol and YM-11133 were 14 and 9.3 times more potent than (-)-amosulalol as alpha-1 adrenoceptor antagonists but approximately 50 and 40 times less potent antagonists at beta adrenoceptors than (-)-amosulalol, respectively. The adrenoceptor blocking profile of the racemate is approximately 2-fold less potent than that of the (+)-isomer at alpha and that of the (-)-isomer at beta adrenoceptors. The affinities of (+/)-, (-)- and (+)-amosulalol and YM-11133 obtained from radioligand binding experiments (pKi) using rat brain membrane correlated well with those obtained from in vitro experiments (pA2) at alpha-1 (r = 0.884), alpha-2 (r = 0.977), beta-1 (r = 0.993) and beta-2 (r = 0.971) adrenoceptors. These results indicate that the stereochemical requirements of alpha and beta adrenoceptors differ for the stereoisomers of amosulalol with the alpha adrenoceptor subtypes favoring the (+)-isomer and the desoxy form and the beta subtypes favoring the (-)-isomer.

Adrenergic alpha-Antagonists↗
PubMed1986

Alpha-1 adrenoceptor antagonist effects of the optical isomers of YM-12617 in rabbit lower urinary tract and prostate.

The alpha-1 adrenoceptor antagonist effects of the optical isomers of YM-12617 (5-[2-[[2-(o-ethoxyphenoxy)ethyl]amino]propyl]- 2-methoxybenzenesulfonamide HCl), a potent and selective alpha-1 adrenoceptor antagonist, were evaluated in the rabbit lower urinary tract and prostate. R-(-)-YM-12617 (1 X 10(-10) to 3 X 10(-9) M) and S-(+)-YM-12617 (3 X 10(-8) to 3 X 10(-7) M) antagonized phenylephrine-induced contraction in a competitive manner in the urinary bladder base (trigone), proximal urethra and prostate. The mean pA2 value for R-(-)-YM-12617 at the alpha-1 adrenoceptor of trigone, urethra and prostate was 9.91, 9.62 and 9.92, respectively, and that for S-(+)-YM-12617 was 8.09, 7.92 and 7.77, respectively. Therefore, R-(-)-YM-12617 is a 50 to 141 times more potent antagonist than S-(+)-YM-12617 at the alpha-1 adrenoceptor in these tissues. The present results also indicate that the alpha-1 adrenoceptor in the lower urinary tract and prostate can distinguish clearly between the optical isomers of YM-12617. Similar results were obtained in the aorta of rabbits in which a dramatic stereochemical preference of R-(-)-YM-12617 for the alpha-1 adrenoceptor also exists.

Adrenergic alpha-Antagonists↗
PubMed1986

Effects of sodium butyrate and dibutyryl cyclic AMP on thermosensitivity of HeLa cells and their production of heat shock proteins.

When HeLa cells were incubated at 42 degrees C for 6 h with 1 mM sodium butyrate or when cells treated with 1 mM dibutyryl cyclic AMP for 24 h were incubated at 42 degrees C for 6 h, they were more thermoresistant than heated control cells without such drugs. The production of heat shock proteins was not enhanced by the drug treatment. These results suggest that there is a factor (or factors) other than heat shock proteins that accounts for the thermoresistance of HeLa cells.

Bucladesine↗
PubMed1986

An approach to DNA fragment synthesis from unprotected nucleoside.

Oligodeoxynucleotides have been synthesized from unprotected nucleoside by use of morpholinophosphordichloridite as a phosphorylating reagent. This procedure consists of three (in situ) steps; the reaction of 5'-O-protected deoxynucleotide with morpholinophosphordichloridite, the reaction of the resulting on active mononucleotide derivative with the second nucleoside, non-aqueous oxidation, and then removal of amino moiety at phosphate diester linkage.

Base Sequence↗
PubMed1986

[Squamous cell carcinoma of the renal pelvis associated with giant hydronephrosis--report of an autopsy case].

An autopsy case of squamous cell carcinoma of the renal pelvis associated with giant hydronephrosis, which is the fourth case in the Japanese literature, is reported. A 37-year-old man, who had been found to have a left abdominal mass was admitted because of dyspnea and lumbar pain. At autopsy the left kidney contained 2,550 ml of turbid yellowish fluid in the pelvis, with a tumor protruding from the cystic wall. Histologically, the tumor was mostly composed of squamous cell carcinoma, which showed keratinization and pearl formation, with focal transitional cell carcinoma and squamous metaplasia. The ureteropelvic junction was slightly obstructed by muscular hypertrophy and fibrosis.

Adult↗
PubMed1985

Sleep-promoting effects of intraperitoneally administered uridine in unrestrained rats.

An intraperitoneal injection of 0.1 nmol uridine in rats resulted in a transient excess slow-wave sleep if administered shortly before onset of the dark period. The sleep latency was remarkably shortened. A small dose (0.01 nmol) and larger doses (1, 10, 100 nmol) caused no effect. Uridine at a dose of 0.1 nmol was entirely ineffective if injected shortly before onset of the light period, while it resulted in transient excess paradoxical sleep if injected at an early phase of the light period. It is concluded that uridine, if timely administered through a systemic route, may pass the blood-brain barrier to modulate sleep in rats.

Animals↗
PubMed1985

Facilitatory effect of antidromic stimulation on milk ejection-related activation of oxytocin neurons during suckling in the rat.

Oxytocin neurons of the paraventricular nucleus were identified by their antidromic response to stimulation of the neurohypophysis and a short high-frequency burst of spikes displayed before reflex milk ejection in the urethane-anesthetized lactating rat. During suckling, the milk ejection-related bursts recurred at regular intervals. Stimulation of the neurohypophysis at 50-300 pulses/s for 0.5-6 s (current 1 mA) evoked additional burst(s) with the amplitude higher than those of spontaneously occurring ones. Stimulation with subthreshold current for antidromic response or constant-collision test could also facilitate the neurosecretory bursts. Possibly, oxytocin released within the magnocellular nuclei is responsible for these effects.

Animals↗
PubMed1985

Plasma lipoproteins as drug carriers: pharmacological activity and disposition of the complex of beta-sitosteryl-beta-D-glucopyranoside with plasma lipoproteins.

The ability of plasma lipoproteins to act as carriers in site-specific drug delivery systems was evaluated by determining the disposition and pharmacological effects of beta-sitosteryl-beta-D-glucopyranoside (SG, 3). In the disposition studies, [3H]SG was absorbed from the intestinal tract by the formation of chylomicrons and was specifically associated with lipoproteins in vivo. [3H]SG was incorporated into various rat plasma lipoproteins in vitro. [3H]SG complexed with the lower density lipoproteins (d less than 1.063 g/mL), especially with the intermediate density lipoproteins (1.006 less than or equal to d less than 1.019 g/mL) which following intravenous administration to rats. In pharmacological studies, the hemostatic effect of SG in mice and the inhibitory effect of SG on vascular permeability in rats were only observed after intravenous administration of the complexes of SG with the lower density lipoproteins. The same results were obtained after the intravenous administration of the complexes of SG with human and mouse lipoproteins.

Animals↗