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Volume 76, Issue 8
Displaying 1-6 of 6 articles from this issue
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Masayoshi TSUJI, Masaru SAITA, Yoshiomi SOEJIMA, Midori TAKAMORI, Kanj ...1980 Volume 76 Issue 8 Pages 675-684
Published: 1980
Released on J-STAGE: March 29, 2007
JOURNAL FREE ACCESSAnti-carrageenin paw edema effects of 1-(m-trifluoromethylphenyl)-3-(2-hydroxyethyl)-quinazoline-2, 4(1H, 3H)-dione [H-88] and 1-(m-trifluoromethylphenyl)-3-ethylpyridopyrimidine-2, 4(1H, 3H)-dione [HN-37] in rats were dissipated or reduced markedly by adrenalectomy. The effects of both compounds on the pituitary-adrenal axis were therefore investigated in male Wistar rats at 5-6 weeks of age. Oral treatments with H-88 in a dose of 100 mg/kg and HN-37 at 10 mg/kg induced the same degree of responses in intact animals, namely, a marked increase of blood corticosterone level at one hr of the peak time (360%), a decrease of adrenal ascorbic acid level at 3 hr (52-59%), an increase of blood glucose level at 6-12 hr (25-59%) and of liver glycogen level at 12-24 hr (97-153%). In addition, a significant hypertrophy of the pituitary and adrenals (p<0.05) at 6-12 hr and/or atrophy of the thymus and spleen at 3-24 hr were noted. The effect of HN-37 on blood corticosterone level was approximately 10 times as potent as that of H-88 as well as on the carrageenin paw edema. The effects of both compounds on blood corticosterone level were dissipated by adrenalectomy, and those on blood corticosterone level and adrenal ascorbic acid level were abolished by hypophysectomy. These results suggest that hypophysis-adrenal axis stimulation may play an important role in antiedematous effects of N-88 and HN-37.View full abstractDownload PDF (11380K) -
Yukio AZUMA1980 Volume 76 Issue 8 Pages 685-696
Published: 1980
Released on J-STAGE: March 29, 2007
JOURNAL FREE ACCESSA study was made of the PCA reaction in rat hind paw for analysis of the mechanisms of the anaphylactic release of mediators in vivo. Also studied was the function of cyclic AMP in the anaphylactic release of histamine during PCA induced in rats with homologous and heterologous antibody. A close correlation was seen among edema formation, histamine release and decrease of cyclic AMP during homologous and heterologous PCA. Theophylline, epinephrine and isoproterenol increased the cyclic AMP level and strongly inhibited edema formation and histamine release, in all animals. Aminopyrine and trasylol also increased the cyclic AMP level but aminopyrine did not inhibit either edema formation or histamine release in case of heat labile homocytotropic antibody induced PCA in rats and trasylol did not inhibit histamine release in any animal. Methysergide and mepyramine strongly inhibited histamine release but did not alter cyclic AMP levels. Thus, the increase of the cyclic AMP level did not always inhibit the histamine release during PCA in rats. It has also been demonstrated that the PCA reaction in rat hind paw is a suitable model for studying the mechanisms of the anaphylactic release of mediators in vivo.View full abstractDownload PDF (13627K) -
Haruaki NAKAYA, Morio KANNO, Koichi KANDA, Yohtaro OYAMA1980 Volume 76 Issue 8 Pages 697-707
Published: 1980
Released on J-STAGE: March 29, 2007
JOURNAL FREE ACCESSThe electrophysiologic effects of calcium channel blocking agents, diltiazem, verapamil and nifedipine, on the sinus node function were examined in 43 anesthetized closed-chest dogs in comparison with the effects of propranolol. The parameters of sinus node function, i.e. sinus cycle length (SCL), sinus node recovery time determined by overdrive suppression (SRT), both of which are thought to reflect sinus node automaticity, and sinoatrial conduction time estimated by Strauss method (SACT), were evaluated. Intravenously administered diltiazem (0.2 mg/kg), verapamil (0.1 mg/kg) and propranolol (0.1 ?? 0.2 mg/kg) increased SCL and SRT significantly although the increase of these parameters induced by nifedipine (0.03 mg/kg) was not statistically significant. The calcium channel blocking agents did not significantly affect SACT in contrast with propranolol which showed a prolonging effect. Thus calcium channel blocking agents suppressed sinus node automaticity yet had little effect on sinoatrial conduction.View full abstractDownload PDF (13475K) -
Saizo YANAURA, Tomokazu HOSOKAWA, Harumi KITAGAWA, Junzo KAMEI, Miwa M ...1980 Volume 76 Issue 8 Pages 709-716
Published: 1980
Released on J-STAGE: March 29, 2007
JOURNAL FREE ACCESSThe modification of cough reflex by contraction and relaxation of the peripheral airway was investigated in anesthetized dogs. For administration of the drugs directly into the peripheral airway, an arterial cannula was chronically implanted in the right bronchial artery via the right intercostal artery. The cough reflex was induced by electrical stimulation of the upper tracheal mucosa by means of an electrode-cannula. Evaluation of the cough response was made by changes in frequency and amplitude of coughs. Drug solutions were infused for 5 min at a rate of 0.17 ml/min into the right bronchial artery. Intraarterial infusion of isoproterenol, 1-3 μg/min, reduced the amplitude, but had no effect on the frequency of coughs, while that of histamine, 3-10 μg/min, increased the frequency and amplitude of coughs. Atropine, 100 μg/min, caused no significant changes in amplitude and frequency, respectively. Benzonatate, 0.85 mg/min, reduced the frequency, but had no effect on the amplitude. Thus, the tonus of the peripheral airway, in particular the airway contraction, may the increase the frequency of cough reflex by lowering the threshold of the airway receptors.View full abstractDownload PDF (8950K) -
Yumiko OHTAKI, Juro UEDA1980 Volume 76 Issue 8 Pages 717-727
Published: 1980
Released on J-STAGE: March 29, 2007
JOURNAL FREE ACCESSEffects of adenine and adenosine compounds (adenosine, AMP, ATP, cyclic AMP and dibutyryl cyclic AMP) on the contractile responses of helically cut strips of canine superior mesenteric arteries to various agonists (K+, norepinephrine, angiotensin II and Ba2+), to transmural electrical stimulation and on Ca2+-contractures of K+-depolarized strips were studied. The contractions induced by these agonists were suppressed, dose dependently, but to a different degree by these adenosine compounds, with the exception of the potentiating action of ATP on the Ba2+-induced contraction. The suppression of the effect of norepinephrine, angiotensin II and transmural stimulation was appreciably greater than that of K+ and Ba2+. Adenine was equally or more effective in inhibiting the contractions induced by these agonists than were the other adenosine compounds used. The order of relative inhibitory potency was adenine ≥ adenosine ≥ AMP = ATP>cyclic AMP = dibutyryl cyclic AMP. The ATP-induced contraction was influenced in a different manner by each adenosine compound. Adenosine and cyclic AMP did not affect the ATP-induced contraction but AMP and dibutyryl cyclic AMP in a narrow range of concentrations enhanced the contraction. On the contrary, adenine and ATP inhibited the ATP contraction, dose-dependently, resulting in tachyphylaxis, with the repeated application of ATP. The present results suggest that adenine moiety in the molecule plays an important role in the inhibitory action of adenosine compounds, and that the antagonistic action of adenosine compounds is due to their inhibitory actions on Ca2+-influx and Ca2+-release from cell stores.View full abstractDownload PDF (14438K) -
Masayuki NAKANO, Masaharu TAKEUCHI, Koichi SUGENO1980 Volume 76 Issue 8 Pages 729-735
Published: 1980
Released on J-STAGE: March 29, 2007
JOURNAL FREE ACCESSEffects of betamethasone 17, 21-dipropionate (BMDP) and betamethasone (BM) on hypothalamo-pituitary-adrenal cortex axis following the intravenous or subcutaneous administration were studied in rats. The active site of the main metabolite of BMDP—betamethasone 17-propionate (BMP)—and BM was investigated by the stereotaxical implantation of these glucocorticoids. The ether-induced increase of plasma corticosterone was not suppressed by intravenous administration of BMDP in a dose of 300 μg/kg, but BM suppressed this increase at doses over 10 μg/kg. Subcutaneous administration of a large amount of these steroids (BMDP, 20 mg/kg; BM, 16mg/kg) induced a significant suppression of the ether-induced plasma corticosterone increase. The implantation of the main metabolite of BMDP—BMP—into the anterior or medial hypothalamic area and septum was effective in significantly reducing the ether-induced increase of plasma corticosterone. BMP implants into the posterior hypothalamus or pituitary gland proved to be ineffective. In contrast, BM, when placed into the hypothalamic area (anterior, medial or posterior), septum or pituitary, lowered the plasma corticosterone levels.View full abstractDownload PDF (9314K)
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