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Volume 92 (1988)
- Issue 6 Pages 337-
- Issue 5 Pages 271-
- Issue 4 Pages 201-
- Issue 3 Pages 167-
- Issue 2 Pages 61-
- Issue 1 Pages 1-
Volume 92, Issue 2
Displaying 1-9 of 9 articles from this issue
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Kazuo TODOKI1988 Volume 92 Issue 2 Pages 61-67
Published: 1988
Released on J-STAGE: February 23, 2007
JOURNAL FREE ACCESSThe regulatory mechanism of the pulpal microcirculatory hemodynamics was investigated by measuring pulpal blood flow (PBF) in dogs by means of a laser doppler flowmeter. Application of vosodilators (acetylcholine, isoproterenol, histamine, bradykinin and substance P) to the prepared cavity caused an increase in PBF, and norepinephrine reduced PBF. These vasoactive substance-induced responses, but not the bradykinin-induced response, were inhibited by i.v. injection of antagonists (atropine, propranolol, diphenhydramine and [D-Pro2, D-Trp7, 9]-substance P). The effect of bradykinin was inhibited by indomethacin, but not by des-Arg9-[Leu8]-bradykinin. Furthermore, prostaglandin E2 produced a concentration-dependent increase in PBF. These results suggest that acetylcholine, histamine, bradykinin, substance P and norepinephrine, if present, influence the local vasomotor regulation in the dental pulp, and that bradykinin may exert the effect via prostaglandin synthesis. Based on this suggestion, the effect of electrical stimulation of the distal end of the cut inferior alveolar nerve on PBF was studied. The nerve stimulation-induced increase in PBF was inhibited by indomethacin, but not by atropine, propranolol, diphenhydramine, soybean trypsin inhibitor, aprotinin, des-Arg9-[Leu8]-bradykinin, or by (D-Pro2, D-Trp7, 9)-substance P. The experiments show that the increase in PBF produced by stimulation of the inferior alveolar nerve is not mediated by common efferent vasodilatory mechanisms, and it is probably mediated by prostaglandin release via the sensory nerve axon reflex mechanism.View full abstractDownload PDF (6166K) -
Shozaburo SEKIDO, Jinichi HOSONO, Kozo HIRATSUKA, Tsutomu ARAKI, Morio ...1988 Volume 92 Issue 2 Pages 69-96
Published: 1988
Released on J-STAGE: February 23, 2007
JOURNAL FREE ACCESSThe pharmacological properties of MCNU, methyl 6-[3-(2-chloroethyl)-3-nitrosoureido]-6-deoxy-α-D-glucopyranoside, were investigated in laboratory animals. MCNU had no effects on the central nervous, respiratory or the cardiovascular systems, but dilation of isolated auricular vessel was seen. No local anesthetic activity was demonstrated. Treatment with MCNU had practically no influence on the contraction of the isolated phrenic nerve-diaphragm, ileum, vas deferens or uterus. Furthermore, no effects on the passage of charcoal meal, size of the pupil and the contraction of nictitating membrane were observed. MCNU caused a reduction of leucocyte counts, suppression of immunine responses, local irritation, suppression of blood coagulating activity and slight inhibition of gastric secretion. No definite effects were observed on blood glucose level or renal and liver functions. MCNU had no antiinflammatory and diuretic activities and did not cause hemolysis. Vomiting and diarrhea were observed by the administration of MCNU. In conclusion, the major pharmacological effects of MCNU are reduction of leukocyte counts, local irritation and immuno-suppression. The reduction of leukocyte counts induced by MCNU was more significant than that by chlorozotocin, but less than that by CCNU. Other effects may be considered somewhat weak or almost the same extent compared with these agents.View full abstractDownload PDF (17994K) -
Hiroyuki NAKAMICHI, Matsutaro MURAKAMI, Hiroshi SASAKI, Shigenori MIZU ...1988 Volume 92 Issue 2 Pages 97-104
Published: 1988
Released on J-STAGE: February 23, 2007
JOURNAL FREE ACCESSEffects of an antihypertensive drug, guanfacine, on brain regional cyclic AMP and cyclic GMP levels were studied in anesthetized rats. Cyclic nucleotides were analyzed in seven brain regions. Guanfacine decreased blood pressure and heart rate 20 min after administration. Yohimbine inhibited these hemodynamic effects of guanfacine. Guanfacine reduced cyclic AMP levels in the hypothalamus. The reducing effect of guanfacine on cyclic AMP was antagonized by yohimbine in the hypothalamus. Guanfacine lowered cyclic GMP in the cerebellum, medulla oblongata and hypothalamus. Yohimbine inhibited the effect of guanfacine on cyclic GMP in the cerebellum, medulla oblongata and hypothalamus. Prazosin showed no effect on guanfacine induced change of cyclic nucleotides in any brain region. From these results, it is concluded that guanfacine decreased cyclic AMP and cyclic GMP in the hypothalamus. In addition, it is suggested that alpha-2 adrenoceptors mainly modulate these changes of cyclic nucleotides.View full abstractDownload PDF (5268K) -
Masaaki TOMOI, Harunobu ITOH, Sachiyo UEDA, Takaharu ONO, Fumio SHIBAY ...1988 Volume 92 Issue 2 Pages 105-111
Published: 1988
Released on J-STAGE: February 23, 2007
JOURNAL FREE ACCESSEffects of omeprazole, an anti-ulcer drug, on (H+-K+) ATPase activity and gastric acid secretion in a gastric mucosal gland preparation from rabbits were investigated. The mode of action of the substance was compared with famotidine, an H2 antagonist, by examining the effects of both drugs on the (H+-K+) ATPase of the rabbit gastric mucosa and on gastric acid secretion from the isolated rabbit gastric glands. Optimal assay conditions for (H+-K+) ATPase activity differed slightly from that reported for pig gastric mucosa, and they were pH 7.0, 2mM of MgCl2 and 50 mM of KCl. Omeprazole dosedependently inhibited the enzyme activity with an IC50 of 4.2μM, whereas famotidine was not inhibitory even at the highest concentration of 100μM. Acid secretion in the glands was determined by measuring accumulation of 14C-aminopyrine. Omeprazole and famotidine showed almost the same inhibitory effect against histamine-stimulated gastric secretion, and their IC50 values were 0.35μM. Omeprazole inhibited dibutyryl cyclic AMP-stimulated gastric acid secretion, but famotidine was not inhibitory even at the highest concentration of 100μM. The reason for this difference was that (H+-K+) ATPase activity is linked to the final step of acid secretion. From these results, omeprazole can be expected to be useful for the treatment of peptic ulcer disease.View full abstractDownload PDF (5322K) -
Koretake ANAMI, Michihide SETOGUCHI, Hideo SENOH1988 Volume 92 Issue 2 Pages 113-118
Published: 1988
Released on J-STAGE: February 23, 2007
JOURNAL FREE ACCESSEffects of Y-8894 on learning and memory were studied using a radial maze task in intact and scopolamine-induced amnesic mice. The following results were obtained: 1) Repeated administration of Y-8894 (1, 2.5 and 5 mg/kg, i.p.) significantly increased the number of initial correct responses (ICR) in the training session in intact mice, facilitating the learning of the maze task. Dihydroergotoxine (5 mg/kg, i.p.) significantly facilitated the learning of this task in the initial stage of the training session, but non-specifically inhibited the performance in the late stage of training. Ca-hopantenate did not modify the learning of this task. 2) A single administration of Y-8894 (2.5 or 5 mg/kg, i.p.) showed an antagonistic effect on scopolamine (1 mg/kg, s.c.)-induced amnesic mice. Dihydroergotoxine (5 mg/kg, i.p.) and Ca-hopantenate (500 mg/kg, i.p.) also significantly antagonized the ICR-decreasing effect of scopolamine. These results suggest that Y-8894 has an ameliorative and/or facilitative effect on learning and memory in the radial maze task, and Y-8894 is more potent than dihydroergotoxine and Ca-hopantenate.View full abstractDownload PDF (4189K) -
Hiroyuki SONOKI, Yasumi UCHIDA, Takanobu TOMARU, Tsuneaki SUGIMOTO1988 Volume 92 Issue 2 Pages 119-126
Published: 1988
Released on J-STAGE: February 23, 2007
JOURNAL FREE ACCESSEffects of prazosin, dobutamine, isoproterenol and SGB-1534, a new α-blockade, on congestive heart failure (CHF) in dogs were investigated. The model was made by protease injection into the left ventricular free wall, saline loading, and dextran and methoxamine infusions. By this maneuver, left atrial pressure (LAP), systemic vascular resistance (SVR) and left ventricular end-diastolic pressure (LVEDP) were markedly increased, aortic blood flow (AoBF) was decreased, and systemic blood pressure was unchanged. In this model, the intravenous administration of prazosin (0.1 ?? 10.0 μg/kg, i.v.) increased AoBF and decreased LAP in a dose-dependent manner. The improvement of the CHF by prazosin was considered to result from its vasodilating action. SGB-1534 (0.1 ?? 10.0 μg/kg, i.v.) improved the CHF mainly through its vasodilating and positive inotropic actions, which is because SGB-1534 decreased SVR and increased Vmax. The magnitudes of vasodilation by SGB-1534 was greater than those by prazosin. These data indicate that SGB-1534 is useful in the treatment of CHF. Both dobutamine (5-100 μg/kg, i.v.) and isoproterenol (0.001 ?? 0.1 μg/kg, i.v.) improved the CHF through their vasodilating and positive inotropic actions in the canine CHF. The ratio of positive inotropism/vasodilation was greater for dobutamine than isoproterenol. The vasoconstriction by the large dose of dobutamine might participate in this difference between dobutamine and isoproterenol.View full abstractDownload PDF (5806K) -
Toshiyuki KANEZUKA, Yoshikazu HATANAKA1988 Volume 92 Issue 2 Pages 127-143
Published: 1988
Released on J-STAGE: February 23, 2007
JOURNAL FREE ACCESSThe progress of various symptoms in adjuvant arthritic rats (AA-rats) and the effects of anti-rheumatic drugs were continuously observed on the basis of the Weibull distribution function, and the following results were obtained: 1) The cumulative incidence rates F (t) of various symptoms and abnormalities of measured values gradually increased with the passage of time. The relationship between the F (t) and the days after adjuvant injection indicated a simple Weibull distribution function. On the other hand, the bone damages in the distal limb joints indicated a composite Weibull distribution function with two shape parameters (m1 and m2) . It was possible to classify the animals into two groups, fast responders (m1) and slow responders (m2), according to the time of occurrence of bone damages. 2) By using the Weibull probability paper, it was possible to integrate and to evaluate in totality those cases with varying grades of symptoms and cases with different symptoms in the adjuvant-induced syndrome in rats. 3) Azathioprine (AZP) showed an inhibitory effect on the advents of pain and swelling and functional disorders, while indomethacin (IDM), prednisolone (PSL) and gold sodium thiomalate (GST) delayed the advents of these symptoms. As to bone damages in the distal limb joints, IDM, PSL and AZP showed an inhibitory effect in only the fast responder group, while GST showed both an inhibitory and delaying effect in both the fast responder group and the slow one. The above results suggest that the usage of the Weibull distribution function is useful not only for analysis of the morbid condition of AA-rats but also for the evaluation of anti-rheumatic drugs in AA-rats.View full abstractDownload PDF (12598K) -
Shigekatsu KOHNO, Hideki YAMAMURA, Katsuya OHATA, Hiroichi NAGAI, Akih ...1988 Volume 92 Issue 2 Pages 145-157
Published: 1988
Released on J-STAGE: February 23, 2007
JOURNAL FREE ACCESSThe antiallergic effects of 10-(3-quinuclidinylmethyl)phenothiazine (mequitazine) were investigated in vitro. The results obtained were as follows : 1) In the isolated trachea and lung parenchyma of guinea pigs, mequitazine showed a fairly potent antagonistic action against contractions induced by both histamine (Hi) and acetylcholine (ACh). Mequitazine was much less potent in antihistaminic action and slightly more potent in anticholinergic action than ketotifen. The contractions of the preparation by leukotriene (LT) D4 were antagonized by mequitazine, although the potency was moderate, showing an IC50 value of 2.3×10-5 g/ml in the trachea and 5.1×10-5g/ml in the lung parenchyma. Mequitazine had no effect on the contraction of the trachea by PGF2α, but inhibited that of the lung parenchyma with pA2=7.0. 2) Mequitazine (10-6 g/ml) slightly inhibited the Schultz-Dale reaction of the isolated guinea pig trachea, while ketotifen at the same concentration did not show any effect. 3) The contraction of the isolated guinea pig trachea by Ca2+ influx was slightly inhibited by mequitazine (10-5g/ml). 4) Mequitazine competitively inhibited the cyclic AMP-dependent phosphodiesterase activity from the rat lung with a potency of 10 times and 5 times more than those of ketotifen and theophylline, respectively. 5) Mequitazine (10-6 to 10-5 M) suppressed both the anaphylactic and phospholipase A2-induced histamine release from the peritoneal cells of rats. 6) Mequitazine (10-5g/ml) also inhibited the anaphylactic and Ca ionophore-induced histamine release from the leukocytes of the atopic patients and normal subjects. 7) The anaphylactic releases of histamine, LTB4 and peptide LT from the human lung fragments were dosedependently inhibited by mequitazine (10-7-10-5 g/ml).View full abstractDownload PDF (9802K) -
Shigekatsu KOHNO, Hideki YAMAMURA, Katsuya OHATA, Michinori TOGAWA, Hi ...1988 Volume 92 Issue 2 Pages 159-165
Published: 1988
Released on J-STAGE: February 23, 2007
JOURNAL FREE ACCESSAntiallergic effects of mequitazine were investigated in vivo and compared with those of ketotifen and disodium cromoglycate (DSCG). The results obtained were as follows: 1) Mequitazine in doses of 2 and 5 mg/kg given, p.o., 1 hr prior to antigen challenge inhibited dose-dependently the 48-hr passive cutaneous anaphylaxis in rats. Five mg/kg of mequitazine showed almost the same extent of inhibitory activity as that of 1 mg/kg of ketotifen. An i.v. administration of 1 mg/kg DSCG 1 min before antigen challenge also showed a marked inhibition. 2) The experimental asthma induced by challenge with an i.v. injection of antigen in passively sensitized guinea pigs was fairly inhibited by the pretreatment with 5 mg/kg of mequitazine administered p.o., although 2 mg/kg of this drug showed only a slight inhibition. 3) The experimental asthma induced by aerosolized antigen was also fairly inhibited by the pretreatment with 5 mg/kg of mequitazine given p.o.View full abstractDownload PDF (4875K)
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