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Volume 96 (1990)
- Issue 6 Pages 289-
- Issue 5 Pages 205-
- Issue 4 Pages 141-
- Issue 3 Pages 85-
- Issue 2 Pages 41-
- Issue 1 Pages 1-
Volume 96, Issue 4
Displaying 1-6 of 6 articles from this issue
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Eishichi MIYAMOTO1990 Volume 96 Issue 4 Pages 141-152
Published: 1990
Released on J-STAGE: February 20, 2007
JOURNAL FREE ACCESSWhen the stimuli by nerve impulses, neurotransmitters, hormones, peptides and growth factors are administered to the neurons, one of the responses of the nerve cells is the enhancement of Ca2+ influx and/or the release of Ca2+ from the intracellular storage site. Ca2+ may be related to several types of neuronal functions such as biosynthesis of neurotransmitters, stimulussecretion coupling of neurotransmitters and hormones, microtubule assembly-disassembly cycle and many metabolic reactions. Although the precise molecular mechanism mediating the actions of Ca2+ in the brain remains to be elucidated, accumulating evidence suggests that the actions of Ca2+ are mediated through Ca2+-binding proteins. The role of troponin C, a Ca2+-binding protein, was extensively studied in the skeletal muscle first. Subsequently calmodulin, a ubiquitous Ca2+-binding protein, was found to be widely distributed in many tissues and to be in involved in a variety of Ca2+-mediated cellular processes. In an attempt to elucidate Ca2+ actions in the central nervous system, we have been studying Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) and calcineurin (Ca2+/ calmodulin-dependent protein phosphatase). These enzymes have many common substrates and, therefore, may be involved in the neuronal functions via phosphorylation and dephosphorylation of specific proteins.View full abstractDownload PDF (10592K) -
Takashi HIGASHIGUCHI, Koichiro GO1990 Volume 96 Issue 4 Pages 153-161
Published: 1990
Released on J-STAGE: February 20, 2007
JOURNAL FREE ACCESSThe effect of Neurotropin on osteoarthritis was investigated in comparison with those of prednisolone and indomethacin. 1) There were remarkable decreases in the staining intensity to safranin-O and in the contents of uronic acid, total hexosamine and hexose in the articular cartilage of rabbits in which experimental osteoarthritis was induced by the injection of papain into the knee joint. In the Neurotropin-treated group, the decrease in the staining intensity to safranin-O and the contents of uronic acid, total hexosamine and hexose were evidently recovered. On the other hand, in the prednisolone or indomethacin-treated group, the degeneration of the cartilage was even more pronounced than in the control group treated with papain alone. 2) Neurotropin had no effect on the autolytic degradation of cartilage, but promoted the incorporation of 14C-acetate into the proteoglycan in the articular cartilage of rabbits. 3) Both prednisolone and indomethacin inhibited the autolytic degradation and the incorporation of 14C-acetate into the proteoglycan. These results suggested that the therapeutic effect of Neurotropin on osteoarthritis may be due to the improvement of decreased proteoglycan content in the matrix of articular cartilage; and in this respect, it is different from anti-inflammatory drugs such as prednisolone and indomethacin.View full abstractDownload PDF (8489K) -
Nobuyuki HARA, Youichi HARA, Yasuhiro NATSUME, Yoshiaki GOTO1990 Volume 96 Issue 4 Pages 163-168
Published: 1990
Released on J-STAGE: February 20, 2007
JOURNAL FREE ACCESSThe ulcerogenic action of baclofen, a lipophilic derivative of GABA, was studied in the urethane anesthetized rat in relation to body temperature. Baclofen at the doses of 2, 4 and 8 mg/kg, s.c. induced gastric ulceration in a dose-dependent manner in the hypothermic (body temperature : 28 ?? 30°C) rat. Duodenal ulcers were also observed in about 80% of the hypothermic animals treated with the highest dose of baclofen. Baclofen, even at 8 mg/kg, s.c., however, failed to induce gastric ulceration in the normothermic (body temperature: 37 ?? 38°C) rat. Histamine, at the secretagogue dose causing acid secretion as potently as 8 mg/kg of baclofen, induced gastric ulcers in both the hypothermic and the normothermic rats. These results indicate that the ulcerogenic effect of baclofen is closely related to the thermoregulation mechanism and may provide important clues for clarifying the pathophysiology of gastroduodenal ulcers induced by hypothermic treatments such as water-immersion stress ulcers or cold exposure ulcers.View full abstractDownload PDF (5631K) -
Masanori KASHIMATA, Masahiko HIRAMATSU, Naomi MINAMI1990 Volume 96 Issue 4 Pages 169-183
Published: 1990
Released on J-STAGE: February 20, 2007
JOURNAL FREE ACCESSThe number of epidermal growth factor (EGF) receptor in rat hepatic membranes was about 2-hold higher in adult male than in adult female rats. Castration of adult males slightly decreased the EGF receptor number. Castration of neonatal males decreased the number of EGF receptors when they reached sexual maturity. This decrease was restored by the combination of neonatal and pubertal treatments with testosterone. Hypophysectomy caused a marked decrease in the number of EGF receptors in the male animals, and this decrease was not restored by either testosterone or triiodothyronine administration. Continuous administration of human growth hormone (hGH) with an osmotic minipump to normal males reduced the EGF receptor number. In contrast, intermittent administration of hGH twice a day (every 12 hr) to hypophysectomized males and/or normal females significantly increased the EGF receptor number. These results indicate that the number of EGF receptors in rat hepatic membranes is regulated by the secretory rhythm of GH in the pituitary, which may be “imprinted” by neonatal androgen.View full abstractDownload PDF (12384K) -
Shuichi WAKABAYASHI, Hitomi SEKIGUCHI, Kazuhiro KOSAKAI, Seiichiro MOC ...1990 Volume 96 Issue 4 Pages 185-204
Published: 1990
Released on J-STAGE: February 20, 2007
JOURNAL FREE ACCESSAzuletil sodium (AZE, 100 mg/kg, p.o.) did not affect the general behaviors, spontaneous motor activity, pentobarbital-induced hypnosis and body temperature. Furthermore, it did not elicit anticonvulsant and muscle relaxant actions. However, AZE (300 mg/kg, p.o.) elicited a stiff gate and slightly inhibited the spontaneous motor activity and electroshockinduced convulsions. It had no influence on spontaneous EEG activities, even at 30 mg/kg, i.v. AZE inhibited acetic acid-induced writhing moderately at doses above 100 mg/kg. AZE at concentrations up to 10-5 g/ml did not affect agonist-induced contractions of the isolated ileum, trachea, vas deference and uterus, but inhibited serotonin and oxytocin-induced contraction at concentrations above 3 × 10-4 and 10-5 g/ml, respectively; and it also depressed spontaneous movements of the ileum and uterus at concentrations above 3 × 10-4 g/ml. AZE caused no changes in blood pressure (BP), heart rate (HR), left ventricular pressure, ECG, tracheal pressure (TP), femoral blood flow (FBF) and coronary blood flow (CBF) at doses up to 10 mg/kg, i.v. in anesthetized dogs, but it caused an increase or a decrease in BP, an increase in TP and an increase in CBF at 30 mg/kg, i.v. However, even at 300 mg/kg, p.o., it caused no changes in BP and HR in conscious rats. AZE moderately promoted the charcoal transport. AZE at doses up to 300 mg/kg, p.o. did not affect urine volume, urinary electrolyte excretion, blood glucose and prothrombin time. These results suggest that AZE at antiulcer doses of 10 ?? 100 mg/kg, p.o. does not have noticeable effects on general pharmacological properties, and there is no marked differences as compared with those of GAS.View full abstractDownload PDF (14266K) -
[in Japanese], [in Japanese]1990 Volume 96 Issue 4 Pages 205-207
Published: 1990
Released on J-STAGE: February 20, 2007
JOURNAL FREE ACCESSDownload PDF (2053K)
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