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Volume 75, Issue 2
Displaying 1-10 of 10 articles from this issue
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Masanori SATO, Sakae MURATA, Hiroshi NARITA, Midori TOMITA, Keiko YAMA ...1979 Volume 75 Issue 2 Pages 99-106
Published: 1979
Released on J-STAGE: March 29, 2007
JOURNAL FREE ACCESSIn conscious and anesthetized normotensive rats, intravenous administration of diltiazem (0.1-3 mg/kg) produced a dose-related decrease in blood pressure. Administration of diltiazem (1-50 mg/kg) into the duodenum of anesthetized rats also reduced the blood pressure in a dose related manner. In parallel with the change in blood pressure, the heart rate increased in conscious rats and decreased in anesthetized animals. Such an increase in the heart rate was suppressed by pretreatment with propranolol. Similarly, in conscious spontaneously hypertensive rats (SHR), diltiazem dose-dependently decreased the blood pressure and increased the heart rate after intravenous administration (0.03-1 mg/kg). Oral administration of diltiazem (100 mg/kg) also reduced the blood pressure of SHR. In addition, the progressive increase in blood pressure in young SHR was significantly suppressed by chronic oral administration of diltiazem (30 mg/kg). The blood pressure in conscious renal hypertensive rats was also decreased with diltiazem (50 mg/kg p.o.). On the other hand, it was demonstrated that the pressor responses to norepinephrine and angiotensin II in the anesthetized normotensive rats were non-competitively inhibited by intravenous administration of diltiazem at a dose which had no effect on the blood pressure.View full abstractDownload PDF (7966K) -
Yoko UCHIDA, Teruko NOMOTO1979 Volume 75 Issue 2 Pages 107-115
Published: 1979
Released on J-STAGE: March 29, 2007
JOURNAL FREE ACCESSSignificance of the interscapular brown adipose tissue(IBAT) in the thermal response to chlorpromazine(CPZ) during acute and chronic cold exposure was studied in rats. Adult male Wistar-Imamichi rats were exposed to 4°C for 1 (cold-exposed) or 30 days (cold-acclimated). Intraperitoneal injection of 10 mg/kg CPZ caused a more marked and lasted hypothermia in acute cold-exposed rats as compared with that seen in control or in cold-acclimated rats. Hypothermia induced by CPZ was unaffected by removal of IBAT either in control or acute cold-exposed rats. But in cold-acclimated rats, the removal of IBAT potentiated the hypothermia by CPZ. The relative weight of IBAT in cold-acclimated rats was about 3 times heavier than that in control and acute cold-exposed rats. CPZ had no effect on the relative weight of IBAT in all groups examined. Total lipids in IBAT showed no significant changes following CPZ administration in rats of all groups. In acute cold-exposed rats, serum FFA level progressively decreased after CPZ injection. The noradrenaline concentration in IBAT increased after chronic cold exposure and CPZ suppressed this elevation. The results suggest that the thermogenesis related sympathetic activity in the IBAT plays a mediatory role in thermal response to CPZ during cold acclimation.View full abstractDownload PDF (10851K) -
Saizo YANAURA, Tsutomu SUZUKI, Hidetoshi MITO, Aiko SHISHIDO, Noboru K ...1979 Volume 75 Issue 2 Pages 117-126
Published: 1979
Released on J-STAGE: March 29, 2007
JOURNAL FREE ACCESSThis is apparently the first attempt to elucidate the relationship between drug dependence and the osmotic fragility of erythrocyte membrane. The osmotic fragility was measured using a coil planet centrifuge(CPC) system. Utilizing the drug-admixed food(DAF) method, rats were made drug-dependent. The osmotic fragility of morphine-dependent rats was significantly enhanced, compared with that of naive rats. By withdrawing or treating the rats with levallorphan, the osmotic fragility was enhanced more than in the morphine-dependent state. When the morphine-withdrawal rats were again given the morphine-admixed food, the osmotic fragility recovered to the morphine-dependent level. The osmotic fragility of phenobarbital-dependent rats was significantly decreased, compared with that of naive rats. On the contrary, in the phenobarbital-withdrawal rats, the osmotic fragility was significantly enhanced, compared with that of the phenobarbital-dependent rats. With re-treatment of phenobarbital-admixed food, the osmotic fragility was recovered to the levels seen in the phenobarbital-dependent rats. Abstinence signs including weight loss, decrease in food and water intake, adrenal hypertrophy etc., were observed during morphine or phenobarbital withdrawal. The effects of food or water deprivation and application of ACTH on the osmotic fragility were then studied and we found that the osmotic fragility was enhanced with these treatments. These results suggest that enhancement of osmotic fragility during withdrawal of these drugs is partly influenced by these treatments.View full abstractDownload PDF (12655K) -
(2). Anti-inflammatory activityMakoto SATO, Yasuhiro ISHIZUKA, Kunio SEKI, Hisayuki TANIZAWA, Tamotsu ...1979 Volume 75 Issue 2 Pages 127-146
Published: 1979
Released on J-STAGE: March 29, 2007
JOURNAL FREE ACCESSThe anti-inflammatory activity and the mode of action of M 73101, a new non-steroidal analgesic antiinflammatory agent, were investigated in experimental animals and compared with those of reference drugs. M73101 inhibited the increase in vascular permeability induced by acetic acid and its activity was more potent than that of phenylbutazone. M73101 showed a marked inhibitory effect against rat paw edema induced by various phlogistic agents (carrageenin, dextran, histamine, serotonin and bradykinin) and the activities were equal to or more potent than those of aminopyrine, mepirizole and tiaramide HCl. M73101 also inhibited the edema induced by mustard, scalding and anti-rat rabbit serum in rats. In addition, the anti-edematous effect of M73101 on carrageenin-induced rat paw edema was not influenced by spinalectomy or adrenalectomy, indicating that the anti-inflammatory action of M 73101 was not mediated by the central nervous system and the adrenals. Local and oral administration of M73101 inhibited significantly the leucocyte migration into the fluid of CMC pouch in rats and the activity was more potent than phenylbutazone, suggesting that the anti-inflammatory effect of M73101 was due to the direct action at the inflamed site. On the other hand, M73101 did not show any marked activities on the experimental chronic inflammatory models. From these results, it is suggested that M73 101 may be useful for clinical application as a basic analgesic, anti-inflammatory drug with remarkable anti-inflammatory activity in acute and subacute cases. The mechanism of the anti-inflammatory action of M73101 probably involves inhibition of an increase in vascular permeability and leucocyte migration.View full abstractDownload PDF (22220K) -
Issei IMANAGA, Takako KANEDA, Noriko MIYAKAWA1979 Volume 75 Issue 2 Pages 147-157
Published: 1979
Released on J-STAGE: March 29, 2007
JOURNAL FREE ACCESSThe effects of dobutamine on inotropism and chronotropism of the heart were studied in vivo and in vitro and were compared with those of dopamine and isoproterenol. These compounds increased epicardial contractile force and the heart rate of the open-chest, bilaterally vagotomized dog under pentobarbital anesthesia. The dose-ratio for the contraction was [dobutamine: dopamine: isoproterenol=1:0.8:40] and for the heart rate, [=1:1:300]. Both drugs augmented the twitch contraction of the isolated dog ventricular papillary muscle with the dose-ratio of [dobutamine: dopamine: isoproterenol=1:0.7:11]. This mechanical response was associated with an elevation of the plateau voltage and an increase in repolarization of the action potential, but with no alteration of the maximum rate of rise of the action potential, the resting potential and the input membrane resistance. The discharge frequency of the rabbit S-A node pacemaker potential was accelerated chiefly due to an increase in the slope of the diastolic slow depolarization. With concentration of these catecholamines for the equivalent positive inotropic potency on the papillary muscle, this effect of isoproterenol was more potent than the effects of dobutamine and dopamine. These positive inotropic and chronotropic actions of the catecholamines were abolished by a β-receptor antagonist. Those actions of dopamine were markedly reduced by reserpine pretreatment. In addition, dobutamine had little vascular effect. These results indicate that dobutamine has a positive inotropic effect and a less positive chronotropic effect and that such is due to the direct action on the ventricular myocardium and the S-A node through β1-adrenergic receptors.View full abstractDownload PDF (12397K) -
Masami DOTEUCHI, Koichi OTANI, Fumiaki HIROSE, Midori SAI, Akiko HIROS ...1979 Volume 75 Issue 2 Pages 159-170
Published: 1979
Released on J-STAGE: March 29, 2007
JOURNAL FREE ACCESSPharmacological effects of dobutamine(DOB), a positive inotropic drug, on smooth muscles were compared with those of catecholamines such as norepinephrine(NE), epinephrine (E), isoproterenol(ISO) and dopamine (DA). DOB acted as a partial agonist and simultaneously as an antagonist on α-adrenergic receptors in the thoracic artery. Large doses of DOB induced uterine contraction in rabbits, but antagonised the contraction of the vas deferens of guinea pigs, as was induced by electrical stimulation. However, DOB showed a potent activity, similar to that seen with NE or E as an α-adrenergic agonist, on the portal vein. Doses of DOB required to produce a relaxation in the trachea of guinea pigs both in vitro and in vivo were 1/250 and 1/600 of ISO, respectively, and were considerably less regarding inhibition of uterine motility in rats. Inhibiting activity of DOB on the transport rate of intestinal contents in mice and gastro-intestinal motility of rabbits was much less than the activity seen with ISO, E and NE. Spasmolytic activity of DOB was also less than that of ISO, NE and E, but was more than that of DA. It is concluded that DOB is a more selective β1-agonist than ISO because of its weaker activity on α- and β2-receptors. The α-agonist activity of DOB in the portal vein was however, potent.View full abstractDownload PDF (14601K) -
Mitsuo SAKATO, Sumiko TAKAHASHI, Shun-ichi SEKIGUCHI, Nobuyuki CHUJYO1979 Volume 75 Issue 2 Pages 171-183
Published: 1979
Released on J-STAGE: March 29, 2007
JOURNAL FREE ACCESS40 mM K-induced isometric contracture of guinea pig taenia coli in the presence of 30 μM dantrolene showed a rapidly rising peak followed by a plateau and then a low sustained tonic contraction. The plateau was delayed by low Ca so that two phasic contractions, fast and slow, were separated from each other. In K-contracture after 15 sec contact with normal Ca following low Ca condition, the fast phasic contraction but not the slow one regained its tension depressed by preceding low Ca, while the slow phasic contraction recovered from its delay. In the presence of 0.2 μM verapamil, K-contracture consisted of the fast phasic contraction without plateau and of the low tonic contraction. The results suggest that K-contracture in the normal state consists of three components, the fast and slow phasic contractions and the tonic contraction, and that dantrolene inhibits a tonic contraction, whereas verapamil inhibits the slow phasic and the tonic contraction. Thus, the contraction curve of each component was tentatively expressed by exponential function, and for simulation of the observed curves a computer was utilized to synthesize the curves using the components of varying parameters. The simulation was successful when based on the above suggestion.View full abstractDownload PDF (14659K) -
Hideyasu YAMAUCHI, Tadashi ISO, Kozo UDA1979 Volume 75 Issue 2 Pages 185-190
Published: 1979
Released on J-STAGE: March 29, 2007
JOURNAL FREE ACCESSAcid phosphatase and β-glucuronidase were used as marker enzymes of lysosome, and their role in adjuvant-induced uveitis was studied. These enzyme activities in the iris-ciliary processes were increased in the inflamed tissues. Changes in these enzyme activities in the tissues paralleled the development of uveitis. While protein concentration in the aqueous humor as a parameter of vascular permeability was significantly correlated with these enzyme activities, there was no correlation in the leucocyte counts in the aqueous humor. Topically applied dexamethasone reduced the increase in the aqueous protein, the leucocyte migration and the swelling of the iris-ciliary processes, while topically applied indomethacin reduced only the leucocyte migration among these inflammatory parameters. Acid phosphatase activities in the inflamed tissues were reduced also by dexamethasone, but not by indomethacin.View full abstractDownload PDF (7505K) -
Isao YAMAGUCHI, Katsuo IKEZAWA, Sakae MURATA, Hiroshi NARITA, Tomihiro ...1979 Volume 75 Issue 2 Pages 191-199
Published: 1979
Released on J-STAGE: March 29, 2007
JOURNAL FREE ACCESSHypotensive effects of diltiazem hydrochloride (Dil) were examined in DOCA/saline hypertensive rats. Intravenous (10 ?? 300 μg/kg, under urethane anesthesia) or oral (3 ?? 100 mg/kg, in a conscious state) administration of a single dose of diltiazem (Dil) produced a dose-dependent decrease in blood pressure in DOCA/saline hypertensive rats as well as in uninephrectomized (saline loaded) and intact rats. In these experiments, fall in the blood pressure in DOCA/saline rats was 5 to 10 times greater than in other experiments where a different regimen was used. Furthermore, the development of hypertension in DOCA/saline rats was slightly suppressed by repeated oral dosing for 3 weeks of either Dil (15 mg/kg×2/day) or trichlormethiazide (TCM, 1 mg/kg×2/day). Combined administration of Dil and TCM (Dil 15 mg/kg+TCM 1 mg/kg) significantly suppressed the development of hypertension. A similar tendency was also observed when Dil and/or TCM were given orally for 10 successive days to DOCA/saline rats in which the systolic pressure was about 180 mmHg. It was found, however, that the pressor response to norepinephrine or angiotensin-II of DOCA/saline rats given Dil and/or TCM (for 3 successive weeks) was similar to that of control (non-drug-treated DOCA/saline rats), when comparisons were made after bilateral vagotomy and pentolinium treatment. These results indicate that the hypotensive effect of Dil is augmented with the concomitant administration of TCM and that this effect may not be the result of a reduction in the pressor response to norepinephrine or angiotensin-II.View full abstractDownload PDF (10419K) -
Kazumi AKIBA, Kenji ONODERA, Kensuke KISARA, Hideaki FUJIKURA1979 Volume 75 Issue 2 Pages 201-206
Published: 1979
Released on J-STAGE: March 29, 2007
JOURNAL FREE ACCESSEffect of various combinations of Platycodi Radix water soluble extracts (Pla), 1-ephedrine (1-eph), d-pseudoephedrine (d-pseudo) and Ipecacuanhae Radix water soluble extracts (Ipe) on acute toxicity were examined in mice. Oral LD50 of Ipe, d-pseudo and 1-eph was 490 (415-578) mg/kg, 1550 (1360-1767) mg/kg and 1400 (1102-1778) mg/kg, respectively, while that of Pla was over 10 g. LD50 of Pla, Ipe, d-pseudo and 1-eph given intraperitoneally was 1400 (1228-1596) mg/kg, 235 (210-263) mg/kg, 245 (229-262) mg/kg and 300 (259-348) mg/kg, respectively. The ratio of the predicted LD50 value, which was calculated on the assumption that each component drug would be additively toxic when combined, to the observed LD50 value was used for comparison. The combination of d-pseudo with Pla gave a significantly greater LD50 value than the predicted LD50 value, while the combination of 1-eph with Pla showed a LD50 value which was not significantly different from Finney's additive model. A combination of d-pseudo with 1-eph and Ipe, and of 1-eph with Ipe showed a LD50 value which was not significantly different from that of the additive model.View full abstractDownload PDF (7779K)
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