Folia Pharmacologica Japonica
Online ISSN : 1347-8397
Print ISSN : 0015-5691
ISSN-L : 0015-5691
Volume 81, Issue 1
Displaying 1-7 of 7 articles from this issue
  • Akemichi BABA
    1983 Volume 81 Issue 1 Pages 1-12
    Published: 1983
    Released on J-STAGE: March 07, 2007
    JOURNAL FREE ACCESS
    Starting from the findings of Curtis and Watkins in 1960, many studies have been performed to characterize the inhibitory action of taurine on central neurons. Neurochemical and electrophysiological studies have shown the possibility that taurine is an inhibitory neurotransmitter or a neuromodulator. Pharmacological studies have suggested an antiepileptic effect of taurine. The aim of this review is to describe the present status and further aspects of taurine in the central nervous system.
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  • Hirosato IMAI, Masayuki NIWA, Masakatsu NOZAKI, Kaito TSURUMI, Hajime ...
    1983 Volume 81 Issue 1 Pages 13-20
    Published: 1983
    Released on J-STAGE: March 07, 2007
    JOURNAL FREE ACCESS
    In conscious rabbits, the intravenous administration of pindolol (1.25 mg/kg), propranolol (1 mg/kg) and alprenolol (2 mg/kg) induced a highly significant decrease of mean arterial blood pressure and significant bradycardia. In the same model, the intravenous administration of saline, indomethacin, and clidanac did not affect the mean arterial blood pressure and heart rate. Pretreatment with indomethacin and clidanac reduced the effect of these β-blockers on the mean arterial blood pressure and had no effect on the heart rate. Treating of the guinea pig heart homogenate with 1 μM indomethacin or clidanac decreased the number of β-adrenoceptors without changing their affinity. These results suggest that indomethacin and clidanac interfere with β-adrenoceptor-mediated effects.
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  • Masao KOIDA, Masakatsu TAKAHASHI, Keiaki TAKENAGA
    1983 Volume 81 Issue 1 Pages 21-27
    Published: 1983
    Released on J-STAGE: March 07, 2007
    JOURNAL FREE ACCESS
    The rat brain P2 fraction was suspended in Krebs Ringer bicarbonate buffer containing 20 μM bacitracin and incubated at 37°C for 10 min under an atmosphere of 95% O2-5% CO2. Incubation was terminated by centrifugation at 4°C and 10, 000×g for 10 min. The supernatant was designated as the S1 fraction, and from the pellet, the S2 to S4 fractions were collected by repeated suspension, incubation, and centrifugation. The radioimmunoassays of each S fraction revealed the spontaneous release of [5Met] and [5Leu]-enkephalins at the ratio of 2 to 1. The peptide contents gradually decreased from S1 to S4, but the release tended to become constant in S3 and S4. Thus, the effects of some ions and drugs on the release were compared at the stage of obtaining the S3 fraction. The release of both peptides were significantly stimulated in 50 mM KCl buffer, and the stimulatory effect appears to be dependent on Ca2+ concentration. Veratrine and A23187 were also effective stimulants of the release. On the other hand, neither spontaneous nor K+-stimulated release of enkephalins was affected by morphine (1 μM), naloxone (1 μM), kyotorphin (1 or 10 μM), and Li+ (50 mM). Similar results were obtained with the release of 3H-noradrenaline taken up in vitro by the P2 fraction. The usability of the P2 fraction as an in vitro model for the study of stimulus-coupled release of enkephalins was discussed with some limitations found herein.
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  • Hiroshi TAKEDA, Sadao KASAMATSU, Miwa MISAWA, Saizo YANAURA
    1983 Volume 81 Issue 1 Pages 29-37
    Published: 1983
    Released on J-STAGE: March 07, 2007
    JOURNAL FREE ACCESS
    The expectorant effect of brovanexine (BvX) was investigated histologically and histochemically using isolated canine trachea. Following BvX treatment, the number of goblet cells (GC) stained positively with the combination procedure of alcian blue at pH 2.5 or pH 1.0 and periodic acid-Schiff was unaffected. The number of GC which stained blue and purple (stain index B & P) was reduced, while the number of GC that stained red (stain index R) was increased. The thickness of the acini of submucosal glands (SG) markedly decreased with 10-5 and 10-4M BvX, and the ratio of the acinar inner diameter to the tracheal wall thickness significantly increased with 10-4M BvX. Stain index B & P of glandular cells decreased with 10-5 and 10-4M BvX, which was accompanied by a marked increase in the stain index R. BvX treatment caused increases in total saccharide and protein concentrations in the incubation fluid, while N-acetylhexosamine slightly decreased. Both the BvX-induced histological changes in glandular cells and changes in concentrations of macromolecular components in the incubation fluid were much the same degree as those induced by bromhexine (Bh). The BvX-induced histochemical changes in secretory cells, however, were slighter than those induced by Bh. These findings suggest that BvX is an expectorant possessing both the secretagogic action selectively on SG and a mucolytic action toward acid glycoproteins in granules of secretory cells.
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  • Masakazu HOJO, Yoichi YOSHIDA, Yasunori NAGASAKA, Koichi MACHIDA, Hiro ...
    1983 Volume 81 Issue 1 Pages 39-58
    Published: 1983
    Released on J-STAGE: March 07, 2007
    JOURNAL FREE ACCESS
    Cardiovascular actions of guanabenz, a new antihypertensive agent, were studied in comparison with those of clonidine and guanethidine. Guanabenz, administered intravenously, produced a rise of blood pressure which was followed by a prolonged fall in anesthetized dogs. Guanabenz also decreased the heart rate, inhibited the respiration, and produced an alteration in T wave and a prolongation of PQ or TP interval in the ECG of the dog. Such effects of guanabenz on blood pressure and heart rate were observed in the cat, rabbit and rat, but there was a slight species-difference in the effects. Clonidine, but not guanethidine, produced responses similar to those of guanabenz. The potency of guanabenz to produce hypotension and bradycardia was approximately 1/10 that of clonidine and 10 times higher than that of guanethidine. The depressor effect of guanabenz was not observed in the spinal cats; thus, the blood pressure rose after the administration. When guanabenz was administered intracerebroventricularly or into the nucleus tractus solitarius of rats, the initial pressor response was not produced, and the depressor and bradycardiac responses were observed. Guanabenz, administered intravenously or intra-arterially, produced an inhibition of cardiac functions, decreased the blood flow of common carotid and femoral arteries, and elevated the perfusion-pressure of the hindlimb in the dog. In the isolated rabbit and guinea-pig atria, guanabenz produced negative inotropic and chronotropic effects and attenuated the rate of rise of the action potential. The contractile responses to serotonin and histamine in the isolated rabbit thoracic aorta were noncompetitively inhibited by guanabenz. From these results, it is suggested that the hypotensive and bradycardiac actions of guanabenz are mediated via central actions, as well as those of clonidine. Furthermore, in addition to the central actions, it was found that guanabenz acts directly on cardiovascular tissues and attenuates the responsiveness.
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  • Katsuya OHATA, Tamotsu MURATA, Hirohiko SAKAMOTO, Shigekatsu KOHNO, Ma ...
    1983 Volume 81 Issue 1 Pages 59-78
    Published: 1983
    Released on J-STAGE: March 07, 2007
    JOURNAL FREE ACCESS
    General pharmacological properties of guanabenz (GUB), a new anti-hypertensive agent, were studied in comparison with those of clonidine (CLD) and guanethidine (GUD). Intravenous or peroral administration of GUB caused a contraction of the nictitating membrane in cats and mydriasis in mice, while it produced an inhibitions of the gastrointestinal motility in dogs; the motility of isolated rabbit ileum; and chacol transport, salivation and gastric acid secretion in rats. GUB had no or slight inhibitory actions on contractile responses induced by peripheral sympathetic or parasympathetic nerve stimulation in various organs; however, it had antagonistic actions against the norepinephrine-induced contraction of isolated guinea-pig vas deferens. The contractile responses to epinephrine and tyramine in the nictitating membrane and to sympathetic nerve stimulation in isolated guinea-pig vas deferens were potentiated by GUB. GUB specifically antagonized the serotonin-induced contraction of the isolated rat fundus strip and nonspecifically inhibited acetylcholine, histamine or Ba2+-induced contractions of isolated guinea-pig ileum at higher concentrations. GUB exhibited local anesthetic actions and diuretic effects, but had no particular actions on neuromuscular transmission, isolated rat uterus, guinea-pig tracheal muscle and the hematic system. These effects of GUB were found to be almost identical with but less potent than those of CLD. The effects of GUD were basically different from GUB.
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  • Kenji OHMORI, Hidee ISHII, Katsuichi SHUTO, Nobuhiro NAKAMIZO
    1983 Volume 81 Issue 1 Pages 79-104
    Published: 1983
    Released on J-STAGE: March 07, 2007
    JOURNAL FREE ACCESS
    The effects of oxatomide, an anti-allergic drug, on the cardiovascular, digestive and autonomic nervous systems were investigated, and the following results were obtained: Intravenous administration of oxatomide, at doses of 1 mg/kg or more, lowered arterial blood pressure, decreased heart rate, increased femoral blood flow, and depressed the gastrointestinal and uterine movement in anesthetized dogs, rabbits and rats. In in vitro experiments, oxatomide inhibited spontaneous movements of isolated rabbit ileum, isolated guinea pig atrium and isolated rat uterus at considerably high concentrations of 10-6M or more. The antagonistic activity of oxatomide for histamine in isolated guinea pig ileum and trachea was observed at concentrations of 3×10-8M or more. Oral administration of oxatomide, however, had no significant influence on the cardiovascular, digestive and autonomic nervous systems and urogenital organs, at doses up to 100 mg/kg. The antigenicity of oxatomide was studied with immunological procedures such as active anaphylactic shock, passive cutaneous anaphylaxis and passive hemagglutination test in guinea pigs, rats and mice. In these tests, neither anaphylactic shock nor allergic reaction was observed. From these results, it is suggested that oxatomide shows little effect on peripheral organs at a dose which elicites the anti-allergic actions and may have no antigenicity to experimental animals.
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