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Volume 99 (1992)
- Issue 6 Pages 381-
- Issue 5 Pages 267-
- Issue 4 Pages 191-
- Issue 3 Pages 123-
- Issue 2 Pages 63-
- Issue 1 Pages 1-
Volume 99, Issue 3
Displaying 1-7 of 7 articles from this issue
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Tadami HOKONOHARA, Yoshiki SHINODA, Nobuaki HORI1992 Volume 99 Issue 3 Pages 123-133
Published: 1992
Released on J-STAGE: February 13, 2007
JOURNAL FREE ACCESSEvoked potentials were recorded in rat cerebral cortical slices. The amplitude of the evoked potential was reduced by perfusion with hypoxic (0 ?? 25%) or low glucose (0 ?? 5 mM) media in a concentrationdependent manner, and the evoked potentials disappeared under severe conditions (below 15% O2, below 3 mM glucose). We investigated the protective effects of oxiracetam on the decrease in evoked potentials under hypoxic (15% O2) and low glucose (3 mM glucose) conditions. Drugs were perfused from 45 min before hypoxic or low glucose perfusion to the end of the experiment. Oxiracetam (10-6 ?? 10-5 M) dose-dependently minimized the amplitude reduction of evoked potentials and prolonged their disappearance time. At a concentration of 10-5M, oxiracetam protected against the disappearance of evoked potential in 5 of the 6 samples under hypoxic conditions and in all 6 samples under low glucose . conditions. Indeloxazine (5×10-6 ?? 10-5 M) and bifemelane (5×10-6 ?? 10-5 M) prevented the reduction of the amplitude of evoked potentials under low glucose conditions. However, these drugs had no effect at a concentration of 10-6 M. These data indicate that oxiracetam has a protective effect against neuronal dysfunction and that this effect develops at a lower concentration than those of indeloxazine and bifemelane.View full abstractDownload PDF (6709K) -
Hiroyuki YOSHIMURA, Kouki WATANABE1992 Volume 99 Issue 3 Pages 135-141
Published: 1992
Released on J-STAGE: February 13, 2007
JOURNAL FREE ACCESSThe present study investigated whether there is any difference between the effects of benzodiazepine and non-benzodiazepine anxiolytics on agonistic behavior in male mice, using an ethopharmacological technique. Agonistic behavior was evoked using a resident-intruder paradigm. The effects of four doses of the following drugs were assessed in either resident or intruder mice: diazepam (vehicle, 1, 2.5 and 5 mg/kg, p.o.) and tandospirone (vehicle, 2.5, 5 and 10 mg/kg, p.o.). Residents and intruders were drugged on alternate test days, and all animals received different sequences of each of the drug conditions according to a random schedule. The injection-test interval was 30 min. When a resident mice were treated with either diazepam or tandospirone, the frequency of attack bite was suppressed significantly in a dose-dependent manner. When intruder mice were treated with diazepam, attack bites by untreated residents were significantly increased, whereas tandospirone was ineffective. Although diazepam caused a significant decrease in both locomotion and rearing, tandospirone did not cause motor dysfunction. These evidence indicate that tandospirone, a 5-HT1A receptor agonist, has different pharmacological properties from diazepam.View full abstractDownload PDF (5176K) -
Masamichi SHOJI, Hitomi SATO, Yasuharu HIRAI, Yasuhiro OGUNI, Chishio ...1992 Volume 99 Issue 3 Pages 143-152
Published: 1992
Released on J-STAGE: February 13, 2007
JOURNAL FREE ACCESSPharmacological effects of Gosha-jinki-gan-ryo extract (KJE) on experimental diabetes induced by cyproheptadine (CPH), aldose reductase activity, and experimental peripheral neuropathy were studied. The effects of KJE were compared with those of Hachimi-jio-gan-ryo extract (HJE). KJE at 417 mg/kg/day (5 times the daily dose in humans) and HJE at 367 mg/kg/day (5 times the daily dose in humans) significantly inhibited the decrease in glucose tolerance by CPH. KJE and HJE inhibited aldose reductase activity, when DL-glyceraldehyde was used as substrate, with IC50 values of 2.68×10-5 g/ml and 4.45×10-5 g/ml, respectively and when D-glucose was used as substrate, with IC50 values of 1.04×10-4 g/ml and 1.55×10-4 g/ml, respectively. KJE at 209 mg/kg/day (2.5 times the daily dose in humans) and HJE at 367 mg/kg/day significantly reduced peripheral neuropathy induced by crushing the sciatic nerve in rats. The potency of these effects of KJE was stronger than that of HJE, when a comparison was made on the basis of the daily dose.View full abstractDownload PDF (7404K) -
Yoshitaka UCHIHASHI, Toshihiko MORIMOTO, Sakutaro TADOKORO1992 Volume 99 Issue 3 Pages 153-160
Published: 1992
Released on J-STAGE: February 13, 2007
JOURNAL FREE ACCESSEffects of mosapramine (Y-516), a new dopamine D2 antagonist, on reverse tolerance (sensitization) after repeated administration of methamphetamine (MAP; 2 mg/kg, s.c.) were investigated by means of ambulatory activity in mice; and they were compared with those of clocapramine (CCP), bromperidol (BPD) and chlorpromazine (CPZ). Y-516 (0.3, 1, 3 and 10 mg/kg, p.o.), CCP (3, 10 and 30 mg/kg, p.o.), BPD (0.1, 0.3 and 1 mg/kg, p.o.), CPZ (1, 3 and 10 mg/kg, p.o.). or 0.5% methylcellulose (MC; solvent, p.o.) were given to mice 30 min before MAP administration. The ambulatory activity was measured by tilting-type activity cages for 3 hr after MAP. These treatments were repeated 5 times at 3 ?? 4 day intervals. Then MAP alone was challenge-administered to all of these mice 3 ?? 4 days after the final administration. Marked reverse tolerance was produced after repeated administration of MC plus MAP. On the other hand, the ambulation-increasing effect of MAP was suppressed dose-dependently in groups pretreated with Y-516 or comparison-drugs, although the development of reverse tolerance was not completely inhibited after the repeated administration. In the challenge-administration of MAP, the ambulation-increasing effect was dose-dependently suppressed in the Y-516 group or the comparisondrug plus MAP group as compared with that in the MC plus MAP group.View full abstractDownload PDF (5594K) -
Naoki YOSHIMURA, Masashi SASA, Osamu YOSHIDA, Shuji TAKAORI1992 Volume 99 Issue 3 Pages 161-166
Published: 1992
Released on J-STAGE: February 13, 2007
JOURNAL FREE ACCESSPharmacological studies were undertaken to elucidate the role of Hachimijiogan in the micturition reflex via the locus coeruleus, using a-chloralose-anesthetized cats. Rhythmic contractions of the urinary bladder induced by continuous infusion of saline into the bladder were dose-dependently inhibited by intravenous injection of Hachimijiogan (10, 30 and 90 mg/kg), as well as flavoxate hydrochloride (1 and 3 mg/kg). In contrast, contraction of the urinary bladder elicited by electrical stimulation of the locus coeruleus was significantly suppressed by intravenous injection of flavoxate, but not affected by that of Hachimijiogan. These results suggest that Hachimijiogan acts on the afferent pathway from the urinary bladder to the locus coeruleus, thereby inhibiting the micturition reflex, while it has no effects on the efferent pathway from the locus coeruleus to the urinary bladder.View full abstractDownload PDF (3895K) -
Susumu OKABE, Mitsuhiro NARITA, Shigeru NAKAJI, Yusuke TAKINAMI, Osamu ...1992 Volume 99 Issue 3 Pages 167-180
Published: 1992
Released on J-STAGE: February 13, 2007
JOURNAL FREE ACCESSA new compound, IGN-2098 [5, 6-dimethyl-2-{4-<3-(1-piperidinomethyl)phenoxy>cis-butenylamino}-4(1H)-pyrimidone-2HCl], was found to be a potential histamine H2-receptor antagonist in the guinea pig atrium. IGN-2098, given p.o., significantly and persistently (for more than 12 hr) inhibited the basal gastric secretion in pylorus-ligated rats. The agent also significantly inhibited the basal gastric secretion when given by the s.c.-, i.d. or i.p.-route. Stimulated gastric secretion in fistula rats in response to histamine, carbachol or pentagastrin was also significantly inhibited with IGN-2098 given s.c. Pretreatment with IGN-2098 (p.o.) significantly protected the gastric mucosa against pylorus ligation-, waterimmersion stress-, histamine-, indomethacin-, HCl·aspirin-, and HCl ethanol-induced gastric lesions. In addition, the agent significantly protected the duodenal mucosa against mepirizole-induced ulcers. Based upon the ED50 values, the antisecretory effects on histamine, carbachol or pentagastrin-stimulated acid secretion were 6.0, 37.0 or 80 times more potent than roxatidine, respectively. As to the antilesion effects on HCl·aspirin-induced gastric lesions or mepirizole-induced duodenal ulcers, IGN-2098 was 8.1 or 14.8 times more potent than roxatidine, respectively. These results suggest that IGN-2098 will be a useful drug for the treatment of gastric and duodenal lesions in man.View full abstractDownload PDF (9219K) -
Takayuki KINOSHITA, Yoshihiko ITOKAZU, Hiromichi NAKAMUTA, Kenji MANNO ...1992 Volume 99 Issue 3 Pages 181-190
Published: 1992
Released on J-STAGE: February 13, 2007
JOURNAL FREE ACCESSMature male rats (SD strain, 8-week-old) were fed with a normal diet or a high cholesterol diet (HC: 1.5 cholesterol and 0.5 % Na cholate in the normal diet) up to 8 weeks, and we examined how the vascular function level of the isolated thoracic aorta and the histological figures of some tissues including the aorta would change. 1) The contracting reactivity to phenylephrine (Phe, 10μM) and the relaxing reactivity to acetylcholine (1μM) measured thereafter remained unchanged during the period of aging and were not influenced by HC-feeding. The addition of L-arginine (Arg, 100μM) did not affect the results. 2) The ability of the aorta to release NO and to relax, which was evaluated as the extent of the endothelium-dependent potentiation by NG-monomethyl-L-arginine (NMA) of the Phe contraction, did not change by HC-feeding up to 4 weeks, but appears to be attenuated after 8-week feeding. 3) The EC50 of NMA for the potentiation estimated without the addition of Arg remained unchanged, while the one in the presence of Arg gradually increased with aging but not with HC-feeding. 4) The histopathological study of the aorta and other tissues failed to detect any notable atherogenic changes in any of the HC-fed groups. The results indicate that under the experimental conditions employed, HC-feeding would not develop any significant atherogenic histopathological changes in the endothelium-smooth muscle preparation, but may induce some dysfunction in the NO-release mediated and auto-regulatory function of the vascular tone.View full abstractDownload PDF (7414K)
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