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Hiroko FUKE, Isamu YAMAGUCHI, Jun HIROI, Shigenobu KUMADA
1978 Volume 28 Issue 4 Pages
511-520
Published: 1978
Released on J-STAGE: December 19, 2006
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Relationship between serum gastrin levels and gastric secretion was studied in Heidenhain pouch dogs. Bethanecol and tetramethylammonium increased gastric secretion without any significant change in the serum immunoreactive gastrin (IRG) level. Histamine increased gastric secretion but decreased the serum IRG level. Tetragastrin evoked gastric secretion concomitantly with an elevation of the serum IRG level, and the relationship was significant. Food-intake promptly increased the serum IRG level which correlated with the increased gastric secretion. Except for the first 15-min value after food-intake, a better correlation was obtained and was almost the same as that with tetragastrin-stimulation. Hexamethonium reduced the food-induced secretion rate in parallel with reduction of the serum IRG level. Correlation between the secretion rate and serum IRG level after dosing was almost the same as that of the control. Atropine and secretin induced a stronger inhibition on the secretion rate than on the serum IRG level. Prostaglandin E/reduced the secretion rate, but produced no inhibitory effect on the serum IRG level. These results suggest that the food-induced gastric secretion in Heidenhain pouch dogs is due to the action of endogenous gastrin, and that hexamethonium and prostaglandin E
1 affect respectively the gastrin and parietal cells. Atropine and secretin affect both parietal and gastrin cells.
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Isamu YAMAGUCHI, Hiroko FUKE, Michiko TSUJITA, Shigenobu KUMADA
1978 Volume 28 Issue 4 Pages
521-526
Published: 1978
Released on J-STAGE: December 19, 2006
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The serum levels of immunoreactive gastrin (IRG) and secretion of gastric juice were simultaneously determined in dogs anesthetized with morphine and urethane. There was a significant positive linear correlation between secretion and serum IRG level in these dogs. Serum IRG level and gastric secretion were reduced by bilateral vagotomy at the neck. The amount of gastric juice was reduced dose-dependently by an intravenous injection of atropine (0.001-0.016 mg/kg), hexamethoniurn (0.064-1 mg/kg) and secretin (2-8 U/kg). The reduction of gastric secretion paralleled that of the serum IRG level. However, the reduction of gastric secretion did not parallel that of serum IRG level under the influence of prostaglandin E
1 (0.002-0.008 mg/kg i.v.) and duodenal acidification. Prostaglandin E
1 and duodenal acidification reduced gastric secretion without the reducing serum IRG level. These findings were discussed in relation to the mechanism of gastric juice stimulation by morphine, and it is suggested that endogenous gastrin release through the vagal and non-vagal pathways participates in morphine-induced gastric secretion. The difference in inhibitory effect between duodenal acidification and secretin suggests the possibility that substances other than secretin may participate in the regulation of gastric secretion in dogs.
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Noboru TODA, Shigehiro HAYASHI, Mizuo MIYAZAKI
1978 Volume 28 Issue 4 Pages
527-534
Published: 1978
Released on J-STAGE: December 19, 2006
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The addition of angiotensin (Ang-) I, II and III caused a dose-dependent contraction of helically cut strips of dog mesenteric arteries. Tachyphylaxis developed following repeated additions of angiotensins. Average median effective concentrations of Ang-I, II and III were 3.7, 0.8 and 2.5×10
-8 M, respectively. Contractile responses to the angiotensins were attenuated to a similar extent by Ang-II antagonists, Sarl Ileu
8 Ang-II and Sar
1 Ala
8 Ang-II, but were unaffected by phentolamine, methysergide and diphenhydramine. The response to Ang-I was significantly reduced by treatment with bradykinin-potentiator B, while the response to Ang-II was not influenced. It may be concluded that Ang-I, II and III produce contractions possibly by activation of same Ang-II receptors and that contractions induced by Ang-I are associated, to some extent, with a conversion to Ang-II in the arterial wall.
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Keitaro HASHIMOTO, Tokumasa TSUKADA, Hiroto MATSUDA, Issei MATSUBARA, ...
1978 Volume 28 Issue 4 Pages
535-544
Published: 1978
Released on J-STAGE: December 19, 2006
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Antiarrhythmic effects of oxprenolol, a β-blocker, were studied quantitatively on arrhythmias produced by epinephrine during halothane anesthesia and by two-stage coronary ligation, and were compared to those of other β-blockers, propranolol and Kö 1400, which have been already reported. Though oxprenolol has potent β-blocking activity, the antiarrhythmic effect on halothane-epinephrine arrhythmia was significantly weaker than those of propranolol and Kö 1400. The effective dose of oxprenolol was 60±18 μg/kg (means±S.E., N=6), which is in the range of the so-called β-adrenergic blocking dose. The weaker antiarrhythmic effect of oxprenolol as compared to propranolol and Kö 1400 is probably due to the intrinsic positive chronotropic effect, which is most clearly observed in oxprenolol as compared to the other two drugs. As for two-stage coronary ligation arrhythmia, oxprenolol suppressed only that observed 48 hours after coronary ligation using higher doses (5 to 10 mg/kg). Other β-blockers also showed similar effects. Because of the high doses necessary for the antiarrhythmic effects on the coronary ligation arrhythmia, the mechanism for suppressing the arrhythmia is probably due to the local anesthetic action of the β-blockers.
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Keisuke TAKEDA, Yumi KATANO, Yoshito NAKAGAWA, Tokumasa TSUKADA, Toyoz ...
1978 Volume 28 Issue 4 Pages
545-551
Published: 1978
Released on J-STAGE: December 19, 2006
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To indentify the histamine-receptors in the canine myocardium, experiments were performed in the canine heart-lung preparation supported by a donor. Smaller doses of histamine produced only an increase in the coronary blood flow. Positive inotropic and chronotropic effects appeared with larger doses. The increase in the coronary blood flow was associated with only a minimal increase in the myocardial oxygen consumption. Pretreatment of the preparation with a prototype H
1-receptor antagonist, mepyramine, resulted in an abolishment of the positive chronotropic effect and a partial inhibition of the coronary vasodilatatory effect, indicating that the histamine-receptors in the dog atrium subserving the chronotropic effect are to be classified as H
1-type. After a representative H
2-receptor antagonist, metiamide, the positive chronotropic effect remained unaffected, while there was a partial inhibition of the coronary vasodilatatory effect. A combined use of both the H
1- and H
2-receptor antagonists brought about a complete suppression of the positive inotropic and the coronary vasodilatatory effects of histamine. These findings indicate that the histamine-receptors in the coronary vasculature belong to the same type of receptors as those in the peripheral blood vessels, and that those in the canine ventricular myocardium cannot be classified either as H
1 or H
2.
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Norio KURIHARA
1978 Volume 28 Issue 4 Pages
553-560
Published: 1978
Released on J-STAGE: December 19, 2006
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Habu venom (HV) incubated with dimercaptosuccinic acid (DMS) or thiosuccinic acid (TMA), was given subcutaneously to mice. The LD50 of HV was 19.7 mg/kg, and after treatment with TMA and DMS, it was 38.1 and 47.1 mg/kg, respectively. The logarithm concentration—mortality curve for the DMS-treated HV shifted to the right compared with the curve for crude HV. The curve for the TMA-treated HV was intermediate between these two. Decimal two mg of HV was then incubated with DMS, and such was given intramuscularly to mice. Hemorrhage and edema which occurred after administration of crude HV were markedly decreased with injection of DMS-treated HV, but the myonecrosis was not greatly affected. At 24 hr after the intramuscular dosing of 1 mg of HV into rats, lymphopenia, acute involution of lymphatic tissue, decrease in liver glycogen and lipid granules in zona fasciculata were apparent, indicating the mark of a stressor. When the DMS-treated venom was administered, the blood picture and histological findings did not differ greatly from the controls. As DMS has marked anti-HV activity, it may be used to investigate treatments for cases of Habu snake bite.
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Nobuo SHIBATA, Hidenori OHASHI, Tadashi TAKEWAKI, Toshiaki OKADA
1978 Volume 28 Issue 4 Pages
561-568
Published: 1978
Released on J-STAGE: December 19, 2006
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The Ca storing site for the carbachol-induced contraction in a high-K medium without adding CaCl
2 was further investigated in the guinea pig taenia caecum. La
3+ (0.05-0.5 mM) caused an increase in peak tension and relaxation rate in the carbachol contraction but reduced or abolished the response to CaCl
2. Simultaneous application of carbachol and CaCl
2 produced tension development the trace of which was comparable to the curve obtained by adding graphically the respective traces of the carbachol-induced and Ca-induced tensions. La
3+ (0.5 mM) abolished the late, sustained component without appreciable change in the initial, transient contraction. The carbachol contraction persisted after 5 min perfusion of solution containing 0.25 mM EGTA (estimated free Ca
2+ concentration less than 10
-8 M). The intracellular Ca content was little changed before and after exposure to carbachol. Histamine induced a transient contraction with a dose-dependent amplitude and resulted in a decrease in tension development produced by subsequently applied carbachol. There was an inversely proportional relationship in amplitude between the histamine contraction and the following carbachol contraction, while the sum of tensions raised by both drugs showed little variation. These results favour an intracellular site for the carbachol-sensitive Ca store. Histamine appears to release Ca
2+ from the carbachol-sensitive store.
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Tetsuro URUSHIDANI, Susumu OKABE, Koji TAKEUCHI, Keijiro TAKAGI
1978 Volume 28 Issue 4 Pages
569-578
Published: 1978
Released on J-STAGE: December 19, 2006
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We found that there are strain differences in aspirin-induced ulceration in pylorus-ligated rats; the ulcer indices varied, from high to low, in the following order: Donryu>Sprague-Dawley>Wistar. Several experiments including analysis of gastric contents or ionic flux, determination of serum aspirin esterase activity, absorption of aspirin from the stomach, prothrombin time and hexosamine content in gastric mucosa and juice were performed to elucidate the origin of the differences. A significantly higher acid output in Donryu rats, and higher hexosamine content in the gastric mucosa of Wistar rats were noted. However, it appears unlikely that these factors only contribute to the marked strain difference in aspirin-induced ulcers. The possible different sensitivity of gastric mucosal cell itself to aspirin must be considered.
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Kazushige SAKAI
1978 Volume 28 Issue 4 Pages
579-587
Published: 1978
Released on J-STAGE: December 19, 2006
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The isolated right hindlimb of the recipient rat was perfused at a constant flow rate through the femoral artery with heparinized blood from the carotid artery of a donor. The preparations were under a 99.0±0.8 mmHg of mean perfusion pressure (N=63) and 3.3±0.1 ml/min of blood flow through the right femoral artery. The actions of adenosine, adenosine tri-, die and monophosphate, inosine monophosphate and inosine on the femoral vascular bed were investigated, respectively. These substances injected into the femoral artery, with the exception of inosine, caused a dose-dependent vasoconstriction always preceded by a temporal vasodilatation. Inosine induced only a prompt vasoconstriction. The vasoconstrictor responses to these substances were diminished or reverted to vasodilator ones after repeated administrations and such were significantly prevented by pretreatment with either reserpine or methysergide. These results indicate that all the purines tested induce a vasoconstriction in the femoral vascular bed of the rat through a common (tryptaminergic) mechanism and that such seem to be potent releasers of 5-hydroxytryptamine from peripheral tryptaminergic storage sites.
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Hiroko MURAKAMI, Eiko KAJI, Tomio SEGAWA
1978 Volume 28 Issue 4 Pages
589-596
Published: 1978
Released on J-STAGE: December 19, 2006
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Influences of verapamil, X-537A, A-23187 and cyclic-AMP on the release of [
3H]-5-HT taken up into rat brain slices, were examined. Incubation with 40 mm KCl induced tritium release which was dependent on the presence of Ca
2+. Verapamil, which blocks Ca
2+ influx in excitable tissues, decreased potassium-induced release of 5-HT. Tritium release induced by ionophore X-537A was not dependent on extracellular Ca
2+ while that induced by A-23187 required Ca
2+. Cyclic-AMP, dibutyryl cyclic-AMP and theophylline did not significantly stimulate 5-HT release either in the presence or absence of Ca
2+.
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Sumio SHIMA, Yoshiko KAWASHIMA, Masanao HIRAI
1978 Volume 28 Issue 4 Pages
597-605
Published: 1978
Released on J-STAGE: December 19, 2006
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3', 5'-cyclic adenosine monophosphate (cyclic AMP) systems in the anesthetized rat adrenal medulla were studied using the technique of a direct infusion of various agents into the adrenal gland, and such is referred to as ‘the retrograde-adrenal vein infusion’ and ‘the intra-adrenal infusion’. A direct administration of acetylcholine into the adrenal gland by the retrograde infusion produced a rapid stimulation of the catecholarnine-release, followed by a delayed activation of the adenylate cyclase in the adrenal medulla. The acetylcholine-induced increase in hormonal secretion and cyclic AMP levels was completely blocked by hexamethonium, indicating the mechanism of nicotinic trans-synaptic stimulation. Intra-adrenal infusion of epinephrine also prevented an increase in cyclic AMP accumulation induced by acetylcholine. This suggests an inhibitory mechanism on the cyclic AMP systems by catecholarnines within the medullary cells. The infusion of propranolol or phentolamine into the gland, in some cases denervated, increased cyclic AMP amounts in the medulla, suggesting a decrease in catecholamine-induced inhibition by a or β-antagonists. These results favor the assumption that the mechanism of catecholamine inhibition of the adenylate cyclase system is mediated by adrenergic interaction. The present studies suggest a mechanism of regulation by catecholamines of the cyclic AMP systems at the early stage of traps-synaptic stimulation, such leading to the delayed increase in the adenylate cyclase activation of the adrenal medulla
in vivo.
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Shingo YANO, Masuo AKAHANE, Masatoshi HARADA
1978 Volume 28 Issue 4 Pages
607-615
Published: 1978
Released on J-STAGE: December 19, 2006
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Gastric motility of stressed rats was studied to determine its role in producing stress-induced gastric lesions. Restraint and water immersion resulted in an increase in gastric motility which consisted of an increase in frequency and amplitude of contractions and a rise in gastric tone. This increase reached maximal levels 2 to 4 hr after stress, and persisted thereafter. Formation of gastric lesions was markedly accelerated after occurrence of the increased gastric motility. In contrast, restraint alone neither produced such a vigorous increase in gastric motility, nor were the gastric lesions severe. A continuous infusion of papaverine during restraint and water immersion inhibited increase in frequency and amplitude of gastric contractions and prevented formation of gastric lesions. It is concluded that increased gastric motility is closely associated with marked formation of gastric lesions under conditions of restraint and water immersion stress and is probably a main cause for their vigorous formation, although formation of lesions occurs to a small degree without involvement of gastric motility.
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Motohiko UEDA, Saburo MATSUDA, Kanya TONDA, Kazuki MATSUNAGA
1978 Volume 28 Issue 4 Pages
617-626
Published: 1978
Released on J-STAGE: December 19, 2006
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Antihypertensive and diuretic effects of trichlormethiazide (TCM) were investigated in the spontaneously hypertensive rats (SHR). The antihypertensive effect of TCM in an acute experiment was observed in male SHR only at a dose over 10 mg/kg given intraperitoneally and not in female SHR and normotensive Kyoto Wistar rats. to a subacute experiment (6 weeks), TCM retarded the development of hypertension in the male SHR loaded with 1 % saline solution at an oral dose over 1 mg kg
-1 day
-1 and such had a diuretic effect. Oral administration of TCM and hydrochlorothiazide (HCT) at 10 mg kg
-1 day
-1 retarded the development of hypertension in the saline loaded female SHR to the same degree, but the relationship between antihypertensive and diuretic effects of both compounds was obscure. Except for decreases of water contents in the thoracic artery and wet weights of hearts, the electrolyte, uric acid, catecholamine and 5-hydroxytryptamine contents in the serum or/and organs were not affected by either TCM or HCT. It is concluded that the antihypertensive effect of TCM and HCT can be observed in SHR with a saline-load, and that the effect may be due to diuretic actions in the male. The relationship was not apparent in female SHR.
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Junnosuke YAMAMOTO, Atsushi SEKIYA, Hiroshi MAEKAWA, Yoshiko KATO
1978 Volume 28 Issue 4 Pages
627-631
Published: 1978
Released on J-STAGE: December 19, 2006
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Effects of the optical isomers of propranolol on blood pressure in the rat, and in the spinal rat during adrenaline infusion were studied to investigate the mechanism of the pressor action of propranolol. Both isomers of propranolol produced a sustained pressor action in the rat and in the spinal rat infused with adrenaline. The magnitude of the pressor action produced by the d- and l-propranolol was proportional to their β-adrenoceptor blocking activities in the heart as was reported by several investigators. It is concluded that the pressor action of propranolol is due to the blockade of the β-adrenoceptors mediating vasodilation in the skeletal muscle vascular beds.
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Hideaki KARAKI, Tadahiko SUZUKI, Norimoto URAKAWA
1978 Volume 28 Issue 4 Pages
633-636
Published: 1978
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Shigeo MURAI, Yasumi OGURA
1978 Volume 28 Issue 4 Pages
636-639
Published: 1978
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Masashi SASA, Seishi IGARASHI, Hiroshi FUJIWARA, Chiyoko INAGAKI
1978 Volume 28 Issue 4 Pages
639-642
Published: 1978
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Toshitaka NABESHIMA, Kazumasa YAMAGUCHI, Tsutomu KAMEYAMA
1978 Volume 28 Issue 4 Pages
642-646
Published: 1978
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Hajime TAMAKI, Yuichi ONODA, Tatsuo KASHIDA
1978 Volume 28 Issue 4 Pages
647-649
Published: 1978
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Hideyo OHSHIKA, Junichiro ENDO, Haruo TAKEMURA, Mamoru TANAKA
1978 Volume 28 Issue 4 Pages
650-652
Published: 1978
Released on J-STAGE: December 19, 2006
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