The Japanese Journal of Pharmacology
Online ISSN : 1347-3506
Print ISSN : 0021-5198
ISSN-L : 0021-5198
Volume 32 , Issue 1
Showing 1-27 articles out of 27 articles from the selected issue
  • Ken-ichi SAITO, Masayoshi GOTO, Hideomi FUKUDA
    1982 Volume 32 Issue 1 Pages 1-7
    Published: 1982
    Released: November 07, 2006
    JOURNALS FREE ACCESS
    To assess the postnatal development of the GABA system in the rat spinal cord, GABA levels and GAD activity, as well as specific [3H]-muscimol binding, were determined in the dorsal and ventral areas. GABA levels and GAD activities did not vary in parallel from 1 to 8 postnatal days since the former decreased and the latter increased. After 8 days, however, increases in GABA levels and GAD activities were observed in tissues from the dorsal area and decreases were observed in tissues from the ventral area. Specific [3H]muscimol binding was unexpectedly high in both areas at 1 and 8 days but decreased linearly up to 22 days. Our findings show that there are distinct differences in the development of the GABA system in the rat spinal cord and brain.
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  • Takashi MATSUBARA, Emiko YOSHIHARA, Tsuyoshi IWATA, Yoshihiro TOCHINO, ...
    1982 Volume 32 Issue 1 Pages 9-21
    Published: 1982
    Released: November 07, 2006
    JOURNALS FREE ACCESS
    The in vitro metabolic fate of 7-alkoxycoumarin was studied using liver microsomes. Microsomal enzyme catalyzed dealkylation of 7-alkoxycoumarin to 7-hydroxycoumarin in the presence of NADPH and molecular oxygen as cofactors was found to be one of the metabolic pathways. The metabolite 7-hydroxycoumarin was further metabolized to unidentified metabolite(s) in the presence of NADPH and O2 at a very slow rate, while the formation of the conjugate of 7-hydroxycoumarin with glucuronic acid was observed in the presence of UDPGA. Microsomal 7-alkoxycoumarin O-dealkylase activity was altered by the substitution of the alkyl group of the substrate, and the substitutions to either an O-propyl or an O-butyl group resulted in a decrease of the enzyme activity. Species differences were observed in the substrate specificity of microsomal O-dealkylation. The O-dealkylase activities in rat liver microsomes were stimulated by pretreatment of the animals with phenobarbital, regardless of the O-alkyl substituent at the 7 position of the coumarin ring. On the other hand, pretreatment with 3-methylcholanthrene or β-naphthoflavone resulted in marked increase of O-deethylation, O-depropylation and O-debutylation activities, but not of O-demethylation activity. Pretreatment of animals with β-naphthoflavone also resulted in remarkable stimulation of 7-hydroxycoumarin-glucuronide formation by the microsomal enzyme, while the conversion of 7-hydroxycoumarin to unidentified metabolite(s) was activated by the pretreatment of rats with only phenobarbital. The O-dealkylation activities in liver microsomes from intact and phenobarbital pretreated rats were inhibited markedly by the addition of hexobarbital to the incubation mixture, but no inhibition was observed with α-naphthoflavone. On the other hand, the O-dealkylation activities in microsomes from β-naphthoflavone-pretreated rats were inhibited remarkably by α-naphtho-flavone. These results confirmed that several microsomal enzymes, including the cytochrome P-450's and UDP-glucuronyltransferase, participate in the biotransformation of 7-alkoxycoumarin, and these enzymes are regulated differently by inducers.
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  • Yasuo ISHII, Yuichi FUJII
    1982 Volume 32 Issue 1 Pages 23-27
    Published: 1982
    Released: November 07, 2006
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    The effects of FM100, a fraction of licorice root with antiulcer activity, on serum gastrin concentration were investigated in rats and dogs. The basal serum gastrin concentration in conscious rats was not affected by 400 mg/kg, p.o. of FM100, but was increased by 800 mg/kg, p.o. of FM100. The serum gastrin concentration of rats in which the antrum had been separated from the fundus was decreased by intraduodenal administration of FM100 in a dose-dependent manner. In conscious beagles, the increase in serum gastrin concentration induced by feeding was not affected by pretreatment with 400 mg/kg p.o. of FM100. However, in anesthetized dogs in which the antrum had been separated from the fundus, the increase in acid output and serum gastrin concentration after administration of peptone solution was prevented by the intraduodenal administration of 200 mg/kg of FM100. These results suggest that the gastric anti-secretory action of FM100 may be due to the inhibition of endogenous gastrin release.
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  • Saizo YANAURA, Hiroshi TAKEDA, Tomoo NISHIMURA, Miwa MISAWA
    1982 Volume 32 Issue 1 Pages 29-35
    Published: 1982
    Released: November 07, 2006
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    Behavior of mucus glycoproteins in tracheal secretory cells after treatment with pilocarpine was investigated histologically and histochemically using the isolated canine trachea. Following pilocarpine treatment, the number of total and neutral glycoprotein-containing goblet cells was reduced concentration-dependently. The number of acid glycoprotein (AGP)-containing goblet cells was not altered with 10-7 and 10-6 M pilocarpine, but significantly decreased with 10-5 and 10-4 M pilocarpine. The thickness of the acini of submucosal glands significantly decreased, and the ratio of acinar inner diameter to tracheal wall thickness increased in 10-5 and 10-4 pilocarpine. AGP content in glandular cells increased in 10-7 and 10-6 M pilocarpine, but markedly decreased at concentrations of 10-5 and 10-4 M. Pilocarpine treatment caused an increase in N-acetylhexosamine concentration in the incubation fluid. Total saccharide concentration in the incubation fluid decreased in 10-7 and 10-6 M pilocarpine, but was not apparently altered at concentrations of 10-5 and 10-4 M. These findings suggest that lower concentrations of pilocarpine stimulate synthesis of AGP in goblet and glandular cells much more preferentially than it stimulates discharge of AGP from the cells, while at higher concentrations, the AGP-discharge effect overcomes the stimulation in synthesis.
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  • Hironaka AIHARA, Hiroaki ARAKI, Masahiro OHZEKI
    1982 Volume 32 Issue 1 Pages 37-45
    Published: 1982
    Released: November 07, 2006
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    The kindling effect of the hippocampus was investigated in rats. The development of behavioral manifestations in hippocampal kindling was similar to that seen in the case of amygdaloid kindling, but many more stimulations were required to evoke behavioral convulsions in the former. The transfer phenomenon from amygdala to hippocampus was evident. There were no differences in effects of drugs on the seizure-discharge and the behavioral convulsions between the amygdaloid and the hippocampal kindled rats. The present results suggest that the amygdala plays an important role in the formation of hippocampal kindling, especially in the manifestation of behavioral changes. The hippocampal kindled rat, as well as amygdaloid kindled rat, is useful animal model for evaluating the antiepileptic effect of various drugs.
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  • Shigehiro HAYASHI, Noboru TODA
    1982 Volume 32 Issue 1 Pages 47-54
    Published: 1982
    Released: November 07, 2006
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    In isolated dog coronary arteries contracted with prostaglandin F, tyramine in concentrations of 10-6 and 5×10-6 M caused relaxations, but it produced contractions at 2×10-5 M or higher. The relaxant response to tyramine was attenuated, but the contractile response was enhanced at the second trial as compared with the responses at the first. Relaxations induced by low concentrations of tyramine were reversed to contractions by treatment with propranolol (10-6 M) or sotalol (10-5 M), and were abolished by cocaine (3×10-6 M) or bretylium (2×10-5 M). In coronary arteries isolated from reserpine (0.5 mg/kg)-pretreated dogs, tyramine produced only a contraction. Under resting conditions, contractions induced by tyramine (5×10-6 to 2×10-3 M) were potentiated by cocaine and propranolol, and were inhibited by phentolamine. Norepinephrine produced a dose-dependent relaxation in the arteries contracted with prostaglandin F. In the presence of propranolol, the arteries under resting conditions were contracted by norepinephrine, the contraction being suppressed by treatment with phentolamine. It may be concluded that relaxations of dog coronary arteries induced by tyramine are mediated by liberation of norepinephrine from adrenergic nerves which stimulates beta-adrenoceptors in the smooth muscle. It seems likely that the tyramine (2×10-5 M or higher) -induced contraction is not mediated by norepinephrine released, but it is partly due to a direct action on alpha-adrenoceptors.
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  • Shinjiro NAKAJYO, Kazumasa SHIMIZU, Atsuko KOMETANI, Kohji KATO, Junji ...
    1982 Volume 32 Issue 1 Pages 55-64
    Published: 1982
    Released: November 07, 2006
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    Bassianol1de (BASS) is a cyclodepsipeptide isolated from cultured mycelia of Beauveria bassiana and is pathogenic to insects. In a longitudinal muscle preparation from guinea pig ileum, 10-6 M BASS almost irreversibly inhibited an isotonic contraction induced by acetylcholine (ACH) and made the dose-response curve shift in parallel to the right (pA2: 7.6). It also inhibited the contractions induced by carbachol, pilocarpine, histamine, 5-hydroxytriptamine (5-HT) and prostaglandin E2, but did not inhibit the contraction induced by barium or a high concentration (40-60 mM) of potassium (high K). When applied to the guinea pig vas deferens, 10-8-10-7 M BASS inhibited an isometric contraction induced by norepinephrine (NE) (3×10-6-10-5 M), phenylephrine (3×10-6-10-5 M) or ACH (10-6-10--5M). When the contractions of the three agonists exceeded the concentrations mentioned above, BASS failed to exert an inhibitory effect upon any of these agonists. It also inhibited the contraction caused by carbachol and histamine, but did not inhibit that induced by barium or high K. BASS itself failed to cause the contraction or relaxation of both muscle preparations. From these results, it is suggested that BASS inhibits the contraction induced by an agonist which acts upon selective sites of smooth muscle cells, but which does not inhibit a contraction induced by an agonist that has an effect on non-selective sites of cells.
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  • Tetsuyuki NASU, Kazumi YUI, Hideyuki NAKAGAWA, Yukio ISHIDA
    1982 Volume 32 Issue 1 Pages 65-71
    Published: 1982
    Released: November 07, 2006
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    The role of glycolysis in the tension development under anoxic conditions in a high-K medium was studied in the intestinal smooth muscle of guinea pig taenia coll. After exposure to the high-K medium (isotonic, 60 mM) under normal oxygen for 30 min, the muscles were exposed to a high-K medium bubbled with N2 gas. The tonic contraction decreased gradually to about 10% of the original level. Glucose was then cumulatively added to the high-K medium under anoxia. The maximum tension was observed following the addition of the higher concentrations of glucose. The muscle tension which developed in the high-K medium with a high concentration of glucose under anoxia was dependent on the external Ca2+ and was inhibited by iodoacetic acid (IAA). The addition of glucose to a high-K medium under anoxia also increased lactate release from the muscle. Pretreatment with 1 mM IAA decreased the lactate release from the muscle. In a Ca2+ -free medium under anoxia, the addition of glucose did not increase the muscle tension although there was a significant increase in the lactate release. In summary, it is considered that the smooth muscle of taenia coli develops tension utilizing energy produced by the glycolytic pathway under anoxia in a high-K medium.
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  • Kazuaki NAITO, Minezo OTSUKA, Shoichi HARIGAYA
    1982 Volume 32 Issue 1 Pages 73-80
    Published: 1982
    Released: November 07, 2006
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    Effects of timepidium bromide (TB; anticholinergic agent), acetylcholine (ACh) and neostigmine (Neost) on gastric and duodenal blood flow distribution were studied by the use of 131I-labeled macro-aggregated human serum albumin (MAA) in rabbits. In normal rabbits, gastric blood flow was found to be uneven in various regions of the stomach: anterior corpus (50% of total gastric blood flow)>posterior corpus (40%)> pyloric antrum (7%). Intravenous administration of TB (200 μg/kg) to normal rabbits produced a slight increase in total gastric blood flow, but the increase in the mucosal layer of the pyloric antrum was considerable. On the other hand, ACh (10 μg/kg, i.v.) and Neost (50 μg/kg, i.v.) significantly reduced the total gastric blood flow, in particular, the mucosal blood flow in the anterior and posterior corpus. This reduction in blood flow was virtually abolished by TB and was restored to the normal level. These results suggest that these cholinergic or anticholinergic drugs affect the gastric blood flow and that these effects may be mediated through muscarinic receptors. Blood flow in the duodenum was only slightly changed by these drugs.
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  • Ryuichiro ANDOH, Shinobu SAKURADA, Takumi SATO, Norio TAKAHASHI, Kensu ...
    1982 Volume 32 Issue 1 Pages 81-89
    Published: 1982
    Released: November 07, 2006
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    Potentiating effects of prostaglandin E2 (PGE2) on bradykinin and capsaicin responses were studied in 34 gallamine triethiodide immobilized cats. Single neurons were recorded from the medial thalamus by using stainless steel microelectrodes. The animals were given agents into the femoral artery through a retrogradely inserted cannula. Of the 22 neurons responding to bradykinin, 13 were potentiated by the injection of PGE2, and the remaining 9 neurons were ineffective. Nine of the 17 neurons responding to capsaicin were also potentiated by PGE2. PGE2 significantly shortened the mean latency of bradykinin to fire the neuronal activity without changing the duration, but with the injection of capsaicin, there was no change in latency and duration in the presence of PGE2. Aspirin suppressed the increased activity of the medial thalamic neurons produced by bradykinin, and this suppression was antagonized by arterial infusion of PGE2. However, the activity of medial thalamic neurons with capsaicin was scarecely affected by aspirin. These results suggest that the bradykinin-induced activity of medial thalamic neurons may be mediated by PGE2 and that the mechanism of activation of nociceptive neurons produced by capsaicin is different from that of bradykinin.
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  • Michio KOJIMA, Takashi BAN, Hideaki SADA
    1982 Volume 32 Issue 1 Pages 91-102
    Published: 1982
    Released: November 07, 2006
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    The correlation between the steady state and non-steady state depression of Vmax by 50 μM disopyramide was investigated in 2.7, 5.4 and 8.1 mM [K+]o using isolated guinea-pig papillary muscles. An elevation of [K+]0 from 2.7 to 8.1 mM strengthened the depressant action of the drug on Vmax (steady state) at 1 to 5 Hz, but attenuated this action at 0.05 and 0.1 Hz. The Vmax-membrane potential (Vm) relationship (steady state) was examined at stimulation rates of 0.1 and 1 Hz by increasing [K+]o from 2.7 to 19 mM. The drug shifted the normalized Vmax- Vm curve at 1 Hz in a hyperpolarizing direction, but shifted the curve at 0.1 Hz upward at Vm between -90 and -65 mV without a shift along the Vm axis. The recovery process of Vmax (non-steady state) was examined by introducing premature stimuli or by interrupting the basic stimulus of 1 Hz for a certain period. The control recovery processes in three [K+]o were approximated by a triple exponential function (the earliest, intermediate and latest components). The drug slowed the intermediate component, but accelerated the latest one (the earliest component was situated within the refractory period) when [K+]o was elevated from 2.7 to 8.1 mM. The finding that the elevation of [K+]o attenuated the depressant action of disopyramide on the Vmax at 0.05 and 0.1 Hz and accelerated the recovery process of Vmax at long diastolic intervals of more than 10 sec was quite unique.
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  • Fumitoshi ASAI, Eiki SATOH, Masakazu NISHIMURA, Norimoto URAKAWA
    1982 Volume 32 Issue 1 Pages 103-108
    Published: 1982
    Released: November 07, 2006
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    Organic calcium antagonists (l- and d-verapamil, D600, and diltiazem) were examined for their effects on muscle twitches of isolated phrenic nerve-diaphragm muscle preparations of mice. The calcium antagonists (1×10-6 to 7.5×10-5 M) increased the amplitude of muscle twitches induced by nerve stimuli with short durations (0.04 to 0.4 msec) of rectangular pulses. However, these agents were poorly effective on twitches induced by nerve stimuli with longer durations over 0.6 msec or by direct shocks. The potentiative effect was reversible, reproducible and dependent on their concentrations. Diltiazem was the most effective among the four agents tested. The twitch increase produced by all of the agents was demonstrated at concentrations of external Ca++ above 0.6 mM. At Ca++ concentrations below 0.5 mM, the tension of the indirectly induced muscle twitch was partially inhibited in the presence of these agents. Caffeine, theophylline, isoproterenol or hypertonic potassium ions increased the tension of indirectly induced muscle twitches. The potentiative effect of the organic calcium antagonists, however, was discriminated from those induced by the other agents under some conditions. From these results, it is suggested that the organic calcium antagonists alter the reactivity of the preparation to nerve shock. The potentiative effect of the agents on indirectly induced muscle twitch may include an increase in the number of fibers contracting per nerve impulse through increasing transmitter release from the nerve terminal, but not an increase in contractility of an individual muscle fiber.
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  • Kayoko MOROI, Tetsuro KUGA
    1982 Volume 32 Issue 1 Pages 109-120
    Published: 1982
    Released: November 07, 2006
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    The effect of tetrachlorvinphos (TCVP) on liver procainesterase (PROCase) and procaine toxicity was studied in rats. TCVP is an organophosphate with an inducible effect on drug metabolizing enzymes. A single oral dose of 500 mg/kg of TCVP caused a remarkable decrease in PROCase (40% of control) 24 hr later and increased the motality after injection of procaine (250 mg/kg, i.p.) from 54% to 87%. Conversely, it was observed that PROCase elevated to 140% of the control and mortality decreased from 54% to 25% on day 3. With repeated administration of TCVP (500 mg/kg/day) for 5 days, the PROCase activity that was inhibited on day 1 was gradually restored to normal levels by 5 days and the mortality alterd to 25%. The inducible effect on PROCase was examined using desmethyl-TCVP, a metabolite of TCVP without inhibitory effect on the enzyme; PROCase activity was enhanced to 1.6-fold of the control and procaine concentration in the brain was reduced to 30% of the control, accompanied with no death of rats after procaine injection. Electrophoresis of the solubilized liver microsomal fraction confirmed the inducible effect of TCVP on PROCase; microsomal protein from the TCVP-treated rat was more deeply stained than that from the control, and the PROCase activity of two anodic bands increased in the TCVP-treated microsomes. These results indicate that TCVP has a dual action on PROCase, inducible and inhibitory, and that the direct inhibitory effect of TCVP might mask the increased amount of the enzyme induced by repeated administration of TCVP. The dual effect of TCVP on PROCase would cause the change in procaine toxicity.
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  • Hajime SHIMADA, Hitoshi ENDOU, Fuminori SAKAI
    1982 Volume 32 Issue 1 Pages 121-129
    Published: 1982
    Released: November 07, 2006
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    “Phosphate-independent maleate-stimulated glutaminase” was investigated as a function of gamma-glutamyl transpeptidase (gamma-GTP). The activity of gamma-GTP in brush border membranes was found to be four times higher than that in the microsomal fraction of the renal cortex. This gamma-GTP activity was exclusively located in the proximal tubule of isolated single nephrons. Specific activity of gamma-GTP was 105 U/g protein (19.8 μU/mm length) in the first 2 mm portion of the proximal tubule and 1352 U/g protein (209 μU/mm) in the last 2 mm portion of the proximal straight tubule. Activity of phosphate independent glutaminase (PIG) was distributed in the same patterns as those of gamma-GTP, not only in the subcellular fractions, but also in the isolated nephron segments. On the other hand, phosphate dependent glutaminase (PDG) was distributed highly in the papillary mitochondrial fraction and in the distal tubule. Observations on the effect of pH on the enzyme activities of gamma-GTP and PDG showed that these enzyme activities were decreased significantly when the pH of the assay mixture was lowered. In the case of PIG, however, the effect of pH was just reversed. From these findings, it may he possible to interpret that gamma-GTP may play an important role in ammonia production in the brush border membrane of the proximal tubule as a function of glutaminase.
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  • Koji KIMURA, Jun-ichi SUDO, Tomoko YAZAWA, Chizuko KOSEKI, Hitoshi END ...
    1982 Volume 32 Issue 1 Pages 131-137
    Published: 1982
    Released: November 07, 2006
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    Cyclic AMP-dependent protein kinase activity and endogenous protein phosphorylating activity are reported for 6 cortical segments of the rabbit nephron which were microdissected and collected according to their morphology. The 6 cortical nephron segments, namely the glomerulus (GIm), proximal convoluted tubule (PCT), proximal straight tubule (PST), cortical ascending limb of Henle's loop (CAL), distal convoluted tubule (DCT), and cortical collecting tubule (CCT), showed protein kinase activities which were increased 1.8-4.9 fold by 10-6 M cyclic AMP in the presence of histone IIA, histone f2b or histone f3 as a protein substrate. However, all these segments showed little or no cyclic AMP dependent increase of activity with either protamine or a-casein as a protein substrate. Cyclic AMP increased the endogenous protein phosphorylation of GIm (10-6 M cyclic AMP), of CAL (10-7 and 10-8 M cyclic AMP), of DCT (10-6 M cyclic AMP) and of CCT (10-8, 10-7 and 10-6 M cyclic AMP). In contrast, PCT showed decreased endogenous protein phosphorylation in the presence of 10-7, 10-5 and 10-4 M cyclic AMP.
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  • Hiroko SAITO, Toshiharu ISHIGURO, Ken'ichi IMANISHI, Ikuo SUZUKI
    1982 Volume 32 Issue 1 Pages 139-142
    Published: 1982
    Released: November 07, 2006
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    A glycoprotein, Aloctin A, which was isolated from Aloe arborescens Mill, markedly inhibits adjuvant arthritis in rats and carrageenininduced edema in rats.
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  • Mizuo MIYAZAKI, Hideki OKUNISHI, Noboru TODA
    1982 Volume 32 Issue 1 Pages 143-148
    Published: 1982
    Released: November 07, 2006
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    The effects of elcatonin (ECT) on the renal hemodynamics and electrolyte levels in plasma and urine were investigated in anesthetized infant beagles (3 months old) and adult beagles (9-10 months old). Intravenous injections of 50 MRC U/kg ECT did not alter the systemic blood pressure, renal blood flow, glomerular filtration rate, and urine flow in intact puppies as well as in puppies and adult dogs subjected to extirpation of the thyroid and parathyroid glands (TPTX). One hundred and twenty min after ECT injection, the plasma calcium concentration decreased by 1.06±0.15 mEq/l in intact puppies and 0.94±0.10 mEq/l in TPTX puppies, but decreased only by 0.38±0.22 mEq/l in adult TPTX dogs. The urinary calcium excretion decreased in all the puppies. The plasma phosphorus concentration decreased by 1.02±0.10 mg/dl, and the phosphorus excretion rate increased 63.6±26.4% in intact puppies; whereas the plasma phosphorus and phosphorus excretion were not altered in TPTX puppies. Diuresis and natriuresis were not obtained. These data suggest that the acute hypocalcemic effect of ECT is dependent on age and is not associated with its action on kidneys.
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  • Fukiko UEDA, Tadashi KISHIMOTO, Hiroshi OZAKI, Norimoto URAKAWA
    1982 Volume 32 Issue 1 Pages 149-157
    Published: 1982
    Released: November 07, 2006
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    Effects of vanadate (NH4VO3: VAN) on tension development, membrane potential and cellular Na content were investigated in guineapig taenia coli depolarized by 62.7 mM KCI solution. VAN (10-4-10-3 M) caused a transient increase in the K developed tension followed by a relaxation. The VAN-induced contraction was observed even in a low Ca (0.13 mM) solution but was inhibited by the removal of external Ca. After the addition of verapamil (5×10-8, 10-7 M), VAN still produced a contraction. Further, the VAN-induced contraction was observed in 142.2 mM KCl (Na 11.9 mM) solution containing ouabain (10-4 M). On the other hand, the effect of VAN to relax the K-induced contraction was dependent on the concentration of VAN. In low Na (choline-substituted) solution, the VAN-induced relaxation was decreased. VAN increased cellular Na content of the depolarized muscle, and a correlation was obtained between the cellular Na accumulation and the relaxation. These results suggest that the relaxation is mainly attributable to the accumulation of Na following the inhibition of the Na pump, while the contraction is independent of the inhibition of the Na pump and less sensitive to the external Ca than the K-induced process.
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  • Eijiro TAGASHIRA, Tameo HIRAMORI, Tomoko URANO, Kenzo NAKAO, Saizo YAN ...
    1982 Volume 32 Issue 1 Pages 159-167
    Published: 1982
    Released: November 07, 2006
    JOURNALS FREE ACCESS
    The correlation between the development of barbital (B)-withdrawal signs and alterations in the metabolism of brain 5-hydroxy-tryptamine (5-HT) was studied. Barbital (B)-dependent rats were prepared by the B-Admixed Food method (DAF method). The B-dependent rats were grouped according to the following 5 states: G-I, B-dependent state; G-II, B-withdrawan state; G-III, cross-administration of nitrazepam (NZP) following B-withdrawal; G-IV, cross-administration of chlorpromazine (CPZ) following B-withdrawal; and G-V, cross-administration of phenytoin following B-withdrawal. The controls were comprised of naive rats (G-VI) and naive rats dosed in the same manner as the dependent rats. The brain 5-HT synthesis rate and the brain 5-hydraxyindole acetic acid (5-HIAA) elimination were measured at 44 to 48 hr after B-withdrawal in all groups (when withdrawal convulsion was still persisting in the B-withdrawn rats of the G-II group). The brain 5-HT synthesis rate was elevated significantly (P<0.001 ) in the rats with persistent B-withdrawal convulsion (G-II) as compared with that in the B-dependent rats (G-I). Cross-administration of nitrazepam caused the elevation of 5-HT synthesis rate with B-withdrawal to be inhibited to the dependent level in parallel with the inhibition of B-withdrawal signs. On the other hand, CPZ and phenytoin, which inhibit B-withdrawal convulsion slightly, failed to recover completely the 5-HT turnover rate during B-withdrawal. From these results, it is obvious that the elevation of the brain 5-HT synthesis rate with B-withdrawal plays an important role in eliciting B-withdrawal convulsion.
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  • Akira SAITO, Yutaka KASUYA, Katsutoshi GOTO
    1982 Volume 32 Issue 1 Pages 169-179
    Published: 1982
    Released: November 07, 2006
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    The relationship between morphological and functional changes in adrenergic nerves and the development of supersensitivity in the rat vas deferens was comparatively investigated after surgical denervation, chemical sympathectomy by 6-hydroxydopamine, daily treatment of animals with reserpine, or local application of colchicine to the hypogastric plexus. The order of ability to produce supersensitivity, as judged by the extent of the increase in the pD2 value of norepinephrine and the maximum response to norepinephrine, was as follows: denervation=colchicine> 6-hydroxydopamine>reserpine. These procedures produced alterations in morphological characteristics of the nerve ending with severeness of degeneration in the following order: denervation>6-hydroxydopamine>colchicine>reserpine. Twitch contractions induced by transmural nerve stimulation were slightly reduced after colchicine or 6-hydroxydopamine treatment, markedly reduced by reserpine, and abolished by denervation. Therefore, the development of supersensitivity in the rat vas deferens is not necessarily in proportion to the morphological or functional changes in adrenergic nerves. The results suggest that some neurofactor, e.g. trophic factor, is involved in the control of the drug sensitivity of smooth muscle in addition to the neurotransmitter itself.
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  • Fumiaki HATA, Etsuo KONDO, Shigeru KONDO, Kimiya KAGAWA, Hajime ISHIDA
    1982 Volume 32 Issue 1 Pages 181-187
    Published: 1982
    Released: November 07, 2006
    JOURNALS FREE ACCESS
    Radiolabeled E-643, a newly developed antihypertensive compound, bound specifically to a preparation obtained from rat brain with a maximum of 85 f moles of binding sites per mg protein and a dissociation constant of 0.59 nM. Prazosin markedly inhibited the binding, while yohimbine and clonidine were only weak inhibitors. Other characteristics of the binding of [3H] E-643 to the brain and its specific binding to preparations of peripheral rat organs were also studied. The present findings suggest that [3H]E-643 is useful for labeling α1-adrenoceptors.
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  • Yoshiyuki OGAWA, Seizaburo KANOH
    1982 Volume 32 Issue 1 Pages 189-194
    Published: 1982
    Released: November 07, 2006
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    We undertook comparative studies on the binding of cerebral proteolipids to LPS using rabbits, rats and chickens in order to clarify the differences in inactivating effects of proteolipids from these three sources on the pyrogenicity of LPS. The Sephadex LH-20 column elution profiles of lipid phosphorus and cerebrosides were not significantly different for the three sources of proteolipid, but a larger amount of proteolipid-protein possessing LPS pyrogenicity inactivating potency was eluted with chloroform(C)/methanol(M) (4:1) in rats and chickens than in rabbits. A complex of proteolipid-protein with LPS was obtained in C effluent from incubation mixtures of rat and chicken proteolipids with LPS, corresponding to our previous observation with rabbit proteolipid. The increasing order of binding capacity of the proteolipids derived from the three species was as follows: chicken, rat and rabbit, which was in parallel with pyrogenic inactivating potency. From these data, we suggest that the difference in pyrogenic inactivating potency among the proteolipids of some species depnds on the difference in binding capacity of the proteolipids to LPS or probably lipid A.
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  • Kazuo NUNOKI, Toshihiko IIJIMA
    1982 Volume 32 Issue 1 Pages 195-197
    Published: 1982
    Released: November 07, 2006
    JOURNALS FREE ACCESS
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  • Masahiko HIRAMATSU, Keiko HATAKEYAMA, Naomi MINAMI, Masayoshi KUMEGAWA
    1982 Volume 32 Issue 1 Pages 198-201
    Published: 1982
    Released: November 07, 2006
    JOURNALS FREE ACCESS
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  • Takashi HAGIWARA, Kazunari KIMURA, Toshio OBATA, Sadayuki SHO, Kazuya ...
    1982 Volume 32 Issue 1 Pages 202-204
    Published: 1982
    Released: November 07, 2006
    JOURNALS FREE ACCESS
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  • Kazumasa EHARA, Satoshi MATSUMOTO, Nobuyoshi YOSHIDA, Takayoshi KUNO, ...
    1982 Volume 32 Issue 1 Pages 205-208
    Published: 1982
    Released: November 07, 2006
    JOURNALS FREE ACCESS
    Download PDF (205K)
  • Eiichi SAKURAI, Yoshiko KIN, Gen FUKUSE, Noboru HIKICHI, Hiroshi NIWA
    1982 Volume 32 Issue 1 Pages 209-212
    Published: 1982
    Released: November 07, 2006
    JOURNALS FREE ACCESS
    Download PDF (202K)
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