Publications by authors named "Masuo Akahane"

Introduction: The effect of beta3-adrenergic receptor agonists on beta cells in the islets of Langerhans is not yet clear. This study examined the beta3-adrenergic receptor agonist on beta cells in the islets of Langerhans.

Methods: Obese diabetic C57BL/KsJ-db/db mice were treated with KTO-7924, a newly-developed beta3-adrenergic receptor agonist for 28-day.

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Obese (fa/fa) Zucker rat is a spontaneous genetic obesity model and, by comparison with lean Zucker rat, exhibits hyperphagia, hyperinsulinemia, and hyperlipidemia. The aim of this study was to examine the physiological difference concerning adiponectin between obese (fa/fa) Zucker rats and control lean Zucker rats. We therefore measured plasma adiponectin level and analyzed adiponectin and adiponectin receptor 1 mRNA expression in retroperitoneal white adipose tissue (RT WAT), brown adipose tissue (BAT), liver, and soleus muscle.

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We aimed to examine the effects of KTO-7924 (beta3-adrenoceptor agonist) on lipid metabolism and mRNA expressions in retroperitoneal white adipose tissue (RP WAT) in obese (fa/fa) Zucker rats using DNA microarray. Oral KTO-7924 for 28 days significantly decreased RP WAT weight, plasma triglyceride, free fatty acid, and insulin, and improved insulin resistance in oral glucose tolerance tests. In RP WAT of KTO-7924-treated rats, DNA microarray analysis revealed specifically enhanced mRNA expressions of uncoupling protein 1 (UCP1) and cytochrome c oxidase subunit VIII-H (COX8H), which are reportedly highly expressed in brown adipose tissue (BAT).

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Our aim was to determine the effect of a beta3-adrenoceptor agonist on plasma adiponectin levels and on the level of expression of mRNA for adiponectin, adiponectin receptor 1, and adiponectin receptor 2 in db/db mice. Two weeks' oral administration of CL-316,243 led to decreased plasma levels of hemoglobin A1c, glucose, insulin, triglyceride and free fatty acid, and to an increased plasma adiponectin levels. It also improved insulin resistance in the oral glucose tolerance test.

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We recently reported that short-term treatment with KAT-681 (KAT), a liver-selective thyromimetic, inhibits the development of preneoplastic lesions in rat livers and may be a candidate chemopreventive agent for hepatocarcinogenesis. In this study, time-course observations of hepatocellular proliferative lesions were carried out during short-term and long-term treatment with KAT to investigate its anti-hepatocarcinogenic effects. The hepatocellular proliferative lesions in male F344 rats were induced by the initiation treatment of diethylnitrosamine (DEN), followed by treatment with 2-acetylaminofluorene (2-AAF) and partial hepatectomy (PH).

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To examine the potential inhibitory effects of a novel liver-selective thyromimetic, KAT-681 (KAT), on the development of hepatocellular proliferative lesions, male F344 rats were given a single intraperitoneal injection of 150 mg/kg diethylnitrosamine (DEN), followed by gavage administration of 7.5 mg/kg per day of 2-acetylaminofluorene (2-AAF) twice daily from weeks 2 to 4 with partial hepatectomy (PH) at week 3. From 5 weeks after the completion of 2-AAF administration, the rats were orally dosed with 0.

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Since, in the human ureter, both beta(2)- and beta(3)-adrenoceptors mediate adrenergic-stimulation-induced relaxation, selective beta(2)-/beta(3)-adrenoceptor agonists might prove clinically useful for relieving ureteral colic and promoting stone passage. We evaluated the beta-adrenoceptor subtype selectivity and ureteral-relaxing efficacy of (-)-2-[4-(2-[[(1S,2R)-2-hydroxy-2-(4-hydroxyphenyl)-1-methylethyl]amin] ethyl)phenyloxy]acetic acid (KUL-7211), a new beta-adrenoceptor agonist, in vitro. In rat isolated organs, its selectivities, for inhibition of spontaneous uterine contraction (mediated via beta(2)-adrenergic stimulation) and inhibition of colonic contraction (via beta(3)-adrenergic stimulation) versus increase in atrial rate (via beta(1)-adrenergic stimulation), were 56.

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Purpose: We compared the effect of a beta 3-adrenoceptor (AR) agonist with that of beta 1 and beta 2-AR agonists on the urethra and bladder in the dog and rat.

Materials And Methods: In an in vitro experiment we studied the relaxant effect of subtype selective beta-AR agonists in canine and rat urethral and bladder smooth muscle using an organ bath method. In addition, in urethane anesthetized rats we measured urethral pressure and bladder pressure simultaneously in the presence of the beta 3-agonist CL316243 and the beta 2-agonist procaterol in 4 or 5 animals.

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We compared the effects of CL-316243, a selective beta(3)-adrenoceptor agonist, and CGP-12177A, a nonconventional partial beta-adrenoceptor agonist, on the KCl-induced contraction in the isolated canine ureter. CL-316243 concentration dependently relaxed the ureteral contraction, the pD(2) value being 7.75 +/- 0.

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This report proposes a beta(3)-adrenoceptor (AR) selective agonist, 2-[2-chloro-4-(2-([(1S,2R)-2-hydroxy-2-(4-hydroxyphenyl)-1-methylethyl]amino)ethyl)phenoxy]acetic acid (1a), as a novel agent for treating urinary bladder dysfunction. This compound and its relatives have a unique feature among beta(3)-AR agonists: two chiral carbons are adjacently structured on the left side of the molecule. To study the relationship between the stereoconfiguration of the vicinal chiral carbons in 1a and beta-AR agonistic activity, the four stereoisomers were synthesized via oxazolidinone prepared by intracyclization involving inversion of the beta-hydroxy group.

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Aims: To investigate the effects of selective beta(2)- and selective beta(3)-adrenoceptor (AR) agonists on prostaglandin (PG) E(2)-induced bladder hyperactivity in conscious free-moving rats.

Methods: Female Sprague-Dawley rats were anesthetized for implantation of bladder, intravenous, and intra-arterial catheters. The effects of a beta(3)-AR agonist (CL316,243) on cystometric and cardiovascular parameters were assessed in conscious rats.

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Objective: To examine the effects of KUR-1246 on oxytocin-induced uterine contractions, the cardiovascular system, and general metabolism of pregnant sheep and their fetuses.

Methods: At 123-125 days' gestation, ewes (n = 8) were infused with oxytocin (1.0 mU/kg/minute) to induce uterine contractions.

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Objective: The aims of this study were (1) to evaluate the usefulness of the new beta2-adrenergic stimulant KUR-1246 as a tocolytic agent and (2) to clarify the mechanisms that underlie the diverse inhibitory effects of beta2-stimulants that are seen in human myometria in vitro.

Study Design: The displacement of tritiated ([3H]) (-)CGP 12177 (0.4 nmol/L) by KUR-1246 and other beta2-stimulants was examined with human beta(1)- and beta2-receptors present on membrane fractions.

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The aim of this study was to evaluate the effects of a beta3-adrenoceptor (AR) agonist (CL-316243), an alpha1-AR agonist (phenylephrine), and a loop diuretic (furosemide) on the spontaneous rhythmic contractions of the isolated canine ureter and on an acute ureteral obstruction produced by inflation of a balloon catheter in anesthetized dogs. In the isolated ureter, CL-316243 concentration dependently reduced both the amplitude and frequency of the rhythmic contractions (pD(2): 7.19 +/- 0.

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We first investigated the relaxations of the urinary bladder induced by beta-adrenoceptor agonists in anesthetized cynomolgus monkeys and then employed a variety of beta-adrenoceptor agonists and antagonists in vitro to identify the beta-adrenoceptor subtype responsible for the relaxation (using isolated monkey detrusors). Isoprenaline reduced bladder pressure in a dose-dependent manner. Isoprenaline, noradrenaline and adrenaline each produced a concentration-dependent relaxation of isolated detrusor strips, the rank order of relaxing potencies being isoprenaline > noradrenaline > adrenaline.

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In this study, we used a coactivator-dependent receptor-ligand interaction assay (CARLA), which is a semifunctional in vitro assay, to determine whether hypolipidemic drugs are ligands for the three peroxisome proliferator-activated receptor isotypes (PPARalpha, delta, and gamma). We also evaluated the transcriptional activities of the three PPAR isotypes by transient transfection assays. We found that bezafibrate was a ligand for PPARalpha, delta, and gamma in the CARLA and that bezafibrate induced transcriptional activation of PPARalpha/RXRalpha, PPARdelta/RXRalpha, and PPARgamma/RXRalpha.

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