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Volume 59 (1992)
- Issue 4 Pages 427-
- Issue 3 Pages 267-
- Issue 2 Pages 137-
- Issue 1 Pages 1-
Volume 59, Issue 4
Displaying 1-12 of 12 articles from this issue
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Akio Namimatsu, Ryohei Okazaki, Koichiro Go, Taeko Hata1992 Volume 59 Issue 4 Pages 427-434
Published: 1992
Released on J-STAGE: June 13, 2006
JOURNAL FREE ACCESSIn guinea pigs actively sensitized with ovalbumin, we have observed that nasal hyper-reactivity and hypersensitivity to methacholine causes nasal secretion accompanied by an increase in the density of muscarinic acetylcholine receptor (m-ACh·R) following the appearance of nasal symptoms induced by the ovalbumin challenge. Therefore in the present investigation, we studied the relationship between the density of m-ACh·R and nasal hypersecretion in actively sensitized guinea pigs. There was no relationship between the quantity of nasal secretion and serum IgG1 or IgE levels. On the other hand, the sensitivity to methacholine and nasal secretion induced by methacholine were significantly related to the density of m-ACh·R located on the nasal mucosa. The quantity of nasal secretion induced by allergen was also correlated significantly to the density of m-ACh·R. These results suggest that the nasal hypersecretion observed in the nasal allergic model may be closely associated with an increase in the density of m-ACh·R located on the nasal mucosa.View full abstractDownload PDF (475K) -
Yuzuru Okamoto, Toshio Suzuki, Satoshi Murayama1992 Volume 59 Issue 4 Pages 435-441
Published: 1992
Released on J-STAGE: June 13, 2006
JOURNAL FREE ACCESSThe spinal reflex potentials elicited by electrical stimulation of the tibial nerve were recorded from the lumbo-sacral ventral root in spinal cats. When the thoracic aorta and the bilateral internal mammary arteries were occluded for 10 min, the potentials were completely depressed. Reappearance of these potentials could be observed at about 10 min after removal of the occlusion and they gradually recovered. Intravenous injection of naloxone (1 or 10 mg/kg) or levallorphan (0.1 mg/kg) together with removal of occlusion significantly promoted the recovery of the polysynaptic reflex potential. Morphine (5 mg/kg) showed no particular effect on the recovery of potentials. Furthermore, pretreatment with morphine (5 mg/kg) did not influence the effects of these opioid antagonists. These results suggest that naloxone and levallorphan may preserve or potentiate the interneuronal activities of the lumbo-sacral spinal cord under the ischemic condition and that the effects may not be mediated through morphine-like opioid receptors.View full abstractDownload PDF (392K) -
Noriko Sato, Masamitsu Sakamori, Keiichiro Haga, Shuzo Takehara, Michi ...1992 Volume 59 Issue 4 Pages 443-448
Published: 1992
Released on J-STAGE: June 13, 2006
JOURNAL FREE ACCESSThis paper describes the 5-hydroxytryptamine3 (5-HT3) receptor antagonism of Y-25130 ((±)-N-(1-azabicyclo[2.2.2]oct-3-yl)-6-chloro-4-methyl-3-oxo-3, 4-dihydro-2H-1, 4-benzoxazine-8-carboxamide monohydrochloride) in the rat cerebral cortex, isolated rabbit heart and isolated guinea pig ileum. In an in vitro binding assay, Y-25130 inhibited the specific binding of [3H]quipazine to 5-HT3 receptors at the synaptic membranes of the rat cerebral cortex with a K; value of 2.9 nM, the same as that of ondansetron. Metoclopramide, 5-HT and 2-methyl-5-HT also showed an inhibitory effect, but their affinities for 5-HT3 receptors were lower than that of Y-25130. Y-25130 showed low affinity for histamine H1 receptors (IC50 = 4.4 μM) but it could not reveal any affinities for the other receptors (5-HT1A, 5-HT2, dopamine D1, dopamine D2, α1-adrenoceptor, α2-adrenoceptor, muscarine and benzodiazepine) even at a 10 μM concentration. In the isolated rabbit heart, Y-25130 antagonized the indirect sympathomimetic responses to 5-HT (pA2 value = 10.06) and this effect was more potent than that of metoclopramide. In the isolated longitudinal smooth muscle of the guinea pig ileum, concentration-contraction effect curves for 5-HT were biphasic in the presence of ketanserin. Y-25130 shifted to the right only in the second phase of concentration-effect curves for 5-HT (pA2 value = 7.04) and its activity was more potent than that of metoclopramide. These results indicate that Y-25130 is a potent and selective 5-HT3 receptor antagonist.View full abstractDownload PDF (438K) -
Masato Okamoto, Taizo Kita, Hirotsugu Okuda, Toshikatsu Nakashima1992 Volume 59 Issue 4 Pages 449-455
Published: 1992
Released on J-STAGE: June 13, 2006
JOURNAL FREE ACCESSDevelopment of tolerance to the nicotine-induced convulsions in rats was examined. Acute intraperitoneal (i.p.) administration of nicotine (2.5, 3.75 and 5 mg/kg) produced convulsions in a dose-dependent manner. Mecamylamine (1 mg/kg, i.p.) antagonized the convulsions, but hexamethonium (5 mg/kg, i.p.) did not modify them. Daily nicotine administration (2.5, 3.75 and 5 mg/kg, i.p.) once a day for 6 days developed tolerance to the convulsions induced by nicotine. After the daily administrations of nicotine for 6 days, the effects of a challenge administration of nicotine (2 mg/kg) on the nicotine-induced convulsions were tested on the 7th-day. Further tolerances were also developed by the 7th-day challenge administration. After the 7th-day test, nicotine levels of the brain and blood 15 min after the challenge injection were measured. With nicotine (5 mg/kg once a day)-treatment, nicotine levels of all the brain regions were increased. In contrast, a similar challenge injection had no effect on blood nicotine level. These results indicate that the development of tolerance to the nicotine-induced convulsions is produced relatively earlier and day by day by daily administrations to rats, which is closely related with the increase in brain nicotine level.View full abstractDownload PDF (405K) -
Ikunobu Muramatsu, Shigeru Kigoshi1992 Volume 59 Issue 4 Pages 457-459
Published: 1992
Released on J-STAGE: June 13, 2006
JOURNAL FREE ACCESSThe selectivity of tizanidine to the imidazoline-receptor and α2-adrenoceptor recognized by 3H-p-aminoclonidine was examined in rat kidney membranes and was compared with those of other imidazoline compounds. Tizanidine bound to the imidazoline-receptors with approximately 20 times higher affinity than the α2-adrenoceptors. The order of relative selectivity to imidazoline receptor was tizanidine > oxymetazoline > clonidine > naphazoline, where clonidine showed an equal affinity to both receptors. Tizanidine may act more potently on the imidazoline-receptors than the α2-adrenoceptors.View full abstractDownload PDF (167K) -
Shiro Shirakura, Jun-ichi Sano, Akira Karasawa, Kazuhiro Kubo1992 Volume 59 Issue 4 Pages 461-467
Published: 1992
Released on J-STAGE: June 13, 2006
JOURNAL FREE ACCESSAn experimental focal segmental glomerular sclerosis (FSGS) was induced by the combined administration of puromycin aminonucleoside (PAN) and protamine sulfate (PS). Blood collections were made on days 0, 37, 70 and 94. Urine collections were made on days 0, 24, 80 and 94. Vehicle-treated rats showed severe proteinuria and an increase in serum total cholesterol (sTC). Benidipine (1 or 3 mg/kg, p.o.)-treated rats exhibited less proteinuria and lower sTC than the vehicle-treated rats. On days 70 and 94, both blood urea nitrogen (BUN) and serum creatinine (sCR) values in the vehicle-treated rats were significantly higher than those in normal rats (without treatment with PAN and PS). On the other hand, the treatment with benidipine (1 or 3 mg/kg, p.o.) attenuated the increases in BUN and sCR. On day 94, vehicle-treated rats showed a significant decrease in creatinine clearance as compared with normal rats, but benidipine (1 or 3 mg/kg, p.o.)-treated rats did not. The histology was examined on day 94. Vehicle-treated rats demonstrated a significantly greater percentage of glomeruli with segmental areas of glomerulosclerosis/hyalinosis, mesangial cell proliferation, and mesangial foam cell. Benidipine (3 mg/kg, p.o.) ameliorated the development of renal regeneration as estimated by histological examination. These results suggest that the Ca-channel blocker benidipine is a favorable drug for preventing the progression of glomerular sclerosis.View full abstractDownload PDF (517K) -
Osami Sakamoto, Hiroshi Mori, Kiyoyuki Kitaichi, Akihide Koda, Taketos ...1992 Volume 59 Issue 4 Pages 469-476
Published: 1992
Released on J-STAGE: June 13, 2006
JOURNAL FREE ACCESSWe have previously reported that 2'', 3'', 5''-tris-O-[N-(2-n-propyl-n-pentanoyl)glycyl]-5-fluorouridine (UK-21), a derivative of 5-fluorouridine (5-FUR), and 1-{6-[N-(2-n-propyl-n-pentanoyl)-glycyl]amino-n-hexylcarbamoyl}-5-fluorouracil (UK-25), a derivative of 5-fluorouracil (5-FU), exert their antitumor activity in mice bearing Meth A or EL4 tumor, while their immunosuppressive effects are mild. In the present study, we examined the effects of these compounds on Sarcoma-180 (S-180), P388, L1210, and Lewis lung carcinoma (LLC) in mice by p.o. administration and on Meth A tumor by i.p.-administration. UK-21 given p.o. showed an antitumor effect against S-180, but it showed virtually no antitumor effects against P388, L1210 and LLC. UK-21 given i.p., on the other hand, strongly inhibited the growth of Meth A tumor at a far lower dose than that for oral administration. The bioavailability of UK-21 given p.o. was suspected to be poor. UK-25 given p.o., in contrast, showed the antitumor effect on all of the tumors employed. The bioavailability of UK-25 given p.o. seemed to be comparable to those of other drugs. These results suggest that UK-21 has the potential for development as a parenterally applicable anticancer drug, and UK-25 has the potential as an oral one.View full abstractDownload PDF (552K) -
Michihisa Tohda, Hisashi Urushihara, Yasuyuki Nomura1992 Volume 59 Issue 4 Pages 477-479
Published: 1992
Released on J-STAGE: June 13, 2006
JOURNAL FREE ACCESSWe characterized the glutamate (Glu) uptake in Xenopus oocytes injected with rat brain mRNA. The Glu uptake into oocytes was higher in mRNA-injected oocytes than in vehicle-injected ones. Na+ omission or addition of tryptophan inhibited the uptake in mRNA-injected oocytes, although it did not affect that in vehicle-injected oocytes. These results suggest that Glu transporters with a tryptophan sensitivity different from that of Glu transporters in native oocytes are expressed after injection of rat brain mRNA.View full abstractDownload PDF (191K) -
Nobuo Nagano, Mikio Yagi, Koji Nishikori1992 Volume 59 Issue 4 Pages 481-483
Published: 1992
Released on J-STAGE: June 13, 2006
JOURNAL FREE ACCESSThe protective effects of antioxidants against elevated blood urea nitrogen (BUN) were studied in newly developed acute renal failure in mice induced by paraquat. The administration of paraquat caused marked azotemia accompanied by a decreased glomerular filtration rate. In contrast, elevated BUN was significantly reduced by the preadministration of either dimethylthiourea, deferoxamine or α-tocopherol. These data suggest that acute renal failure induced by paraquat is mainly related to the hydroxyl radicals produced via the iron-catalyzed Haber-Weiss reaction.View full abstractDownload PDF (209K) -
Mariko Harada, Katsuo Koike, Issei Takayanagi1992 Volume 59 Issue 4 Pages 485-487
Published: 1992
Released on J-STAGE: June 13, 2006
JOURNAL FREE ACCESSThe subtype of propylbenzilylcholine mustard (PrBCM)-sensitive and -resistant muscarinic cholinoceptors in guinea pig ileal muscle was examined using four selective muscarinic antagonists, pirenzepine, AF-DX 116, himbacine and 4-DAMP. The pA2 values of the four antagonists against pilocarpine were not different from their values against carbachol after the treatment with PrBCM and was identified with the values for the m3 subtype. These results suggest that the subtype of PrBCM-sensitive and -resistant muscarinic cholinoceptors in guinea pig ileal muscle is the m3 subtype only and not other subtypes.View full abstractDownload PDF (209K) -
Kazuo Aisaka, Tomoko Miyazaki, Toshinori Hidaka, Tomochika Ohno, Takaf ...1992 Volume 59 Issue 4 Pages 489-492
Published: 1992
Released on J-STAGE: June 13, 2006
JOURNAL FREE ACCESSSodium nitroprusside, nitroglycerin and carperitide (α-human ANP) all reduced mean blood pressure, but only carperitide increased the hematocrit in rats with bilateral renal artery- and ureter-ligation. NG-Monomethyl L-arginine, a selective inhibitor of nitric oxide synthesis, elevated the mean blood pressure but did not change the hematocrit significantly. These findings suggest that ANP has a physiological role in regulating circulatory blood volume distinct from that of NO, although both increase intracellular cyclic GMP in the vasculature.View full abstractDownload PDF (259K) -
Minoru Sasano, Katsuhiko Nakata, Shiro Mita1992 Volume 59 Issue 4 Pages 493-496
Published: 1992
Released on J-STAGE: June 13, 2006
JOURNAL FREE ACCESSThe effect of (4R)-hexahydro-7, 7-dimethyl-6-oxo-1, 2, 5-dithiazocine-4-carboxylic acid (SA3443), a novel cyclic disulfide, on tumor necrosis factor (TNF)-like factor production from Propionibacterium acnes (P. acnes)-primed rat liver macrophages/Kupffer cells was investigated. A remarkable increase in TNF-like activity was detected in the culture supernatants of the liver macrophages/Kupffer cells from P. acnes-treated rats. At concentrations of 1 × 10-6 to 1 × 10-4 M, SA3443 significantly inhibited the production/release of TNF-like factor from these P. acnes-primed/activated liver macrophages/Kupffer cells.View full abstractDownload PDF (224K)
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