Search Results - (Author, Cooperation:A. Fujimura)

2011-08-27

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

2011-08-27

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

2011-08-27

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

2011-08-27

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

2011-08-27

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

2011-08-27

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

2018-06-07

American Association for the Advancement of Science (AAAS)

2375-2548

Natural Sciences in General

1600-0765

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

The lymphatic system is very important for macromolecular clearance in various tissues, especially in the gingiva. However, the kinetics of macromolecular clearance via the lymph flow in the gingiva are poorly understood. The aim of this study was to investigate whether thermal or mechanical stimulation affects macromolecular clearance via the lymph flow in the gingiva. Carbon black suspension was injected into the mandibular gingiva of anesthetized hamsters and its drainage into cervical lymph nodes was examined. Clearance of 14C-methylated bovine albumin and tritiated water from the gingiva and their drainage into submandibular lymph nodes and blood was quantified. The effect of topical warming or massage on clearance of 14C-methylated albumin from the gingiva during a 15 min period was examined. In addition, the influence of neurochemical antagonists on the stimulatory effect of topical warming on albumin clearance was investigated. Submandibular lymph nodes were clearly delineated by carbon black 10 min after the injection. More radiolabeled albumin appeared in submandibular lymph nodes than in serum, while more tritiated water appeared in serum. Topical warming (45°C, 2 min) and warming plus massage (with a silicon rubber brush, 20 s) decreased the radiolabeled albumin in the gingiva 15 min after the injection. There was less radiolabeled albumin in the gingiva after gingival warming plus massage than after warming. Previous injection of HOE140 or propranolol into the gingiva diminished the stimulatory effect of topical warming on albumin clearance. It was concluded that topical warming plus massage improves macromolecular clearance via the lymph flow in hamster gingiva.

Electronic Resource

0304-3991

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Electrical Engineering, Measurement and Control Technology

Natural Sciences in General

Physics

Electronic Resource

0009-8981

Elderly subject ; Seasonal variation ; Total cholesterol ; Total protein

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Medicine

Electronic Resource

0012-821X

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Geosciences

Physics

Electronic Resource

0273-1177

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Physics

Electronic Resource

1420-908X

Springer Online Journal Archives 1860-2000

Medicine

Abstract The effect of econazole on the release of thromboxanes was investigated. It was found that econazole inhibited concentration-dependently the aggregation of guinea pig platelets stimulated with arachidonic acid. The compound also reduced significantly the LTB4-induced contraction of guinea pig lung parenchyma strips and the contraction of rabbit aorta to the effluent of LTD4-stimulated guinea pig lungs, both effects mediated mostly by thromboxane generation. The concentration of TXB2 in the effluents from LTD4 stimulated lungs, assayed by EIA, was significantly reduced following pretreatment of the lungs with 10−4 M and 10−5 M of econazole, whereas the levels of PGE2 were increased. These results demonstrate that econazole is a selective inhibitor of thromboxane synthesis.

Electronic Resource

1432-1041

Probucol ; elevated cholesterol, chronopharmacology

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Medicine

Summary A time-dependent change in the cholesterol-lowering effect of probucol has been evaluated in 20 subjects with elevated cholesterol. Probucol 500 mg was given once daily at 07.00 h (day trial) or 19.00 h (night trial) for 3 months according to a crossover design. Fasting blood samples were obtained during the control period and at the end of each treatment period. Serum concentrations of total and HDL-cholesterol were significantly decreased by both the treatments with probucol [total cholesterol (mmol · l−1): control 6.58; day trial 5.41; night trial 5.10; HDL-cholesterol (mmol · l−1): control 1.35; day trial 1.06; night trial 0.96]. These parameters were significantly lower in the night trial than in the day trial. The data indicate that the cholesterol-lowering effect of probucol varies with its time of administration in subjects with elevated cholesterol.

Electronic Resource

1432-1041

Prazosin ; Urapidil ; Vasoconstrictor response ; laser Doppler flow ; finger tip blood flow ; cold stimulation ; healthy volunteers

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Medicine

Abstract Objectives: Cold stimulation causes a finger skin vasoconstrictor response, which is regulated by stimulation of α-adrenergic receptors and is reduced by administration of prazosin. The purpose of this study was to investigate, using a laser Doppler flowmeter, whether the decrease in the finger skin vasoconstrictor response to cold stimulation produced by administration of two different α1-adrenoceptor antagonists, prazosin and urapidil, was correlated with the corresponding plasma drug concentration, and whether this method could be used to evaluate the relative potency of these α1-adrenoceptor antagonists in human subjects. Method: In thirteen healthy male subjects (20–42 y), finger tip skin blood flow was measured during cold stimulation before and 1, 2, 3, 6, and 9 h after administration of placebo, prazosin (1 mg) or urapidil (60 mg). Results: Both prazosin and urapidil significantly decreased the vasoconstrictor response to cold stimulation. The degree of the decrement in the response indicated by the reduction ratio was significantly correlated with the plasma concentration of prazosin and urapidil. The α1-adrenoceptor blocking activity of prazosin estimated by the regression lines was about 130-times more potent than that of urapidil. Conclusion: These findings suggest that the cold stimulation response of finger skin vasoconstriction may be used to evaluate the relative α1-adrenoceptor blocking potency of drugs.

Electronic Resource

1432-1041

Lomefloxacin ; Furosemide ; Renal clearance ; drug interaction

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Medicine

Abstract The interaction between lomefloxacin, a new quinolone, and furosemide, a loop diuretic, has been examined. Oral lomefloxacin 200 mg and furosemide 40 mg were given together or separately to 8 healthy subjects, and blood and urine samples were obtained over the following 12 h. The plasma concentrations of lomefloxacin following coadministration with furosemide were higher than after lomefloxacin alone and its AUC was increased, and its total and renal clearances were decreased. No change in the pharmacokinetics of furosemide was found after coadministration of lomefloxacin. As quinolones and furosemide are reported to be excreted in urine by the renal tubular anion transport system, the present results suggest that the renal tubular secretion of lomefloxacin is diminished by furosemide. It is not clear whether this pharmacokinetic interaction might be clinically important.

Electronic Resource

1432-1041

Key words Aldosterone ; Omeprazole ; Cimetidine

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Medicine

Abstract Objective: The Effect of omeprazole, a proton pump inhibitor, and cimetidine, an H2-receptor antagonist, on plasma aldosterone (PA) response to angiotensin II (AII) were evaluated. Methods: Furosemide (a loop diuretic agent, 20 mg) was given intravenously to eight healthy subjects during a control period, and after pretreatment with omeprazole (20 mg daily) or cimetidine (800 mg daily) for 6 days. Blood samples for determination of plasma renin activity (PRA), AII, PA, adrenotorticotropic hormone (ACTH) and potassium were obtained just before, and 30, 60 min and 120 min after furosemide administration. Results: PRA, AII and PA increased significantly after furosemide administration whereas ACTH and potassium did not. Significant correlations between plasma AII and PA were obtained in the control and omeprazole trial, but not in the cimetidine trial. The slope of the regression lines of the control and omeprazole trials did not differ significantly. Conclusion: These results suggest that, in contrast to cimetidine, the inhibitory effect of omeprazole on AII-stimulated aldosterone production following dosing with furosemide is negligible.

Electronic Resource

1432-1041

Key words Isoproterenol ; Amrinone ; Elderly; venodilation ; age-related change ; dorsal hand vein technique

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Medicine

Abstract Objective: To investigate the influence of age on the venodilator effect of isoproterenol, a β-adrenoceptor agonist, and amrinone, a selective phosphodiesterase (PDE) III inhibitor, in human subjects. Methods: In eight young and eight elderly male subjects, the drugs were infused into a dorsal hand vein preconstricted with phenylephrine and its diameter was measured using a linear variable differential transformer. Results: The maximum venodilation (Emax) induced by isoproterenol was significantly smaller and the infusion rate of isoproterenol required to induce 50% of maximum venodilation (ED50) was significantly larger in the elderly than in the young subjects [Emax: 29.8 vs 95.1%, ED50: 97.3 vs 51.6 ng ⋅min–1]. A significant age-related change in Emax or ED50 was not observed for amrinone (Emax: 95.8 vs 100.8%, ED50: 40.1 vs 31.6 μg ⋅min–1). Conclusion: The data show that the venodilator effect of amrinone is not influenced by age. As amrinone increases cyclic AMP by inhibition of PDE III, it is suggested that the action of cyclic AMP is not altered by age. The decreased effect of isoproterenol might be caused by reduced production of cyclic AMP in elderly subjects.

Electronic Resource

1432-1041

Key words Lomefloxacin ; Ranitidine; renal clearance ; drug interaction

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Medicine

Abstract Objective: To examine the effect of ranitidine on the renal clearance of lomefloxacin. Setting: Department of Clinical Pharmacology, Jichi Medical School. Methods: Lomefloxacin 200 mg and ranitidine 300 mg or its placebo were given orally in a randomised, double-blind, crossover design. Blood and urine samples were obtained during a 24-h period after dosing. Results: The area under the plasma concentration-time curve and the elimination half-life of lomefloxacin were significantly increased following coadministration with ranitidine. These effects were caused by significant decreases in total (7.8%) and renal (22%) clearance of lomefloxacin. In contrast, creatinine clearance and urinary excretion of electrolytes were not influenced by ranitidine. Conclusion: As lomefloxacin and ranitidine are excreted in urine by renal tubular secretion, the present results suggest that the renal tubular secretion of lomefloxacin is diminished by ranitidine. As the reduction in lomefloxacin clearance is only marginal, it is probable that the drug interaction observed in this study is not of clinical significance.

Electronic Resource

1432-1041

Key words Noradrenaline ; Dopamine ; Venoconstriction

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Medicine

Abstract Objective: To compare the venoconstricting effect of dopamine with that of noradrenaline and to investigate the influence of age on the responsiveness to dopamine in human subjects. Methods: In eight young and eight elderly male subjects, increasing doses of dopamine or noradrenaline were infused into a dorsal hand vein and its diameter was measured using a linear variable differential transformer. Results: There was no significant difference between the maximum venoconstriction (Emax) for dopamine and that for noradrenaline. The infusion rate to induce 50% of Emax (ED50) for dopamine in the young and elderly subjects was 363 ng · min−1 and 352 ng · min−1, and the ED50 for noradrenaline was 40.7 ng · min−1 and 43.8 ng · min−1, respectively. Neither in the Emax nor in the ED50 for these drugs were there significant differences between the young and elderly subjects. Conclusion: The venoconstricting effect of dopamine is 5–20 times less than that of noradrenaline, and aging does not influence the responsiveness to dopamine and noradrenaline in human subjects.

Electronic Resource