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Biomedical subjects

Y Kudo

Publications and source records attributed to Y Kudo.

At least 379 records · Page 21Linked to original sources
PubMed1981

Clinical features and biochemical aspects of red blood cells in Hb Hirosaki.

Hb Hirosaki is a new unstable variant in which CE 1 phenylalanine of alpha-chain is substituted by leucine. Seven patients with hemolytic anemia were found in one family and Hb Hirosaki was detected in four of them. In clinical feature some differences of severity were observed between child and adult patients. The child cases showed relatively severe symptoms with repeated hemolytic crises and drug sensitivity. Otherwise most of adult cases had only mild hemolytic process throughout their past life. The variety of clinical severity suggests that the expression of abnormal gene may be various in this disorder. The mode of inheritance seemed to be autosomal dominant and all the cases in this report were heterozygous state. Macrocytic and hypochromic anemia was characteristic in most cases and red blood cells containing Heinz bodies were dominant in peripheral blood from the splenectomized patients. Accelerated glycolysis and enhanced ATPase activity were outstanding features in the metabolism of erythrocyte in this disorder. The instability of reduced glutathione was also found in three of five cases.

Adenine Nucleotides↗
PubMed1981

[General pharmacology of 6-amino-2-fluoromethyl-3-(o-tolyl)-4(3H)-quinazolinone (afloqualone), a new centrally acting muscle relaxant. I. Effects on the central nervous system (author's transl)].

The general pharmacology of afloqualone, a new centrally acting muscle relaxant, in the CNS was examined in mice and rats and findings compared with those of other central muscle relaxants. Afloqualone showed relatively strong hexobarbital and barbital anesthesia potentiating action. Taking into account the dose ratio of anesthesia potentiating action to the muscle relaxing action, however, the potency of anesthesia potentiating action of afloqualone is lower than that of chlormezanone. At doses producing muscle relaxing action, afloqualone inhibited spontaneous motor activity, methamphetamine-induced hypermotility, pentylenetetrazol-, nicotine-, and maximum electroshock-convulsions, fighting episodes in foot-shocked mice, conditioned avoidance response in rat pole-climbing test, and acetic acid-induced writhing syndrome and lowered normal body temperature. The dose ratios of these pharmacological actions to muscle relaxing action of afloqualone, however, were larger than those of chlormezanone and mephenesin. This suggests that the central depressant activity of afloqualone is less potent and the specificity of muscle relaxing action of afloqualone is higher than those of climbing behaviour, physostigmine-induced death, serotonin-induced heat twitch, and reserpine-induced hypothermia, even at 50 mg/kg. Tolperisone showed neither muscle relaxing action nor other central actions when administered orally.

Agonistic Behavior↗
PubMed1981

[General pharmacology of 6-amino-2-fluoromethyl-3-(o-tolyl)-4(3H)-quinazolinone (afloqualone), a new centrally acting muscle relaxant. II. Effects on the peripheral system (author's transl)].

The general pharmacology of afloqualone, a new centrally acting muscle relaxant, in the peripheral system, was examined in laboratory animals and findings compared with those of some other central muscle relaxants. Afloqualone dose dependently inhibited respiration, lowered arterial blood pressure, decreased heart rate, and slightly increased femoral and renal arterial blood flow in parallel with hypotension, at doses of 1 or 2 to 20 mg/kg iv. in anesthetized cats. Afloqualone also inhibited cardiac movement in situ in anesthetized rabbits and decreased internal pressure in the urinary bladder in anesthetized cats. In in vitro experiments, afloqualone inhibited spontaneous movements of isolated rabbit atrium and ileum and isolated rat uterus at considerably high concentrations of 10(-6) g/ml or more. Oral administration of afloqualone, however, had no significant influence on respiration, the cardiovascular, digestive, and autonomic nervous systems, and urogenital organs, at doses up to 50 mg/kg except for a comparatively potent inhibitory effect on carrageenin-induced paw edema in rats. Afloqualone induced neither surface nor infiltration anesthesia.

Animals↗
PubMed1980

The potent depolarizing action of palytoxin isolated from Palythoa tubercurosa on the isolated spinal cord of the frog.

1. The effects of palytoxin (PTX) isolated from Palythoa tubercurosa were tested on the isolated intra-arterially perfused spinal cord of the frog. The resting and evoked potentials were recorded by means of a sucrose-gap technique. 2. PTX caused a marked depolarization of both ventral and dorsal roots. The minimum effective concentration was extremely low, approximately 10(-11) M. During the depolarization the evoked ventral and dorsal root potentials were markedly reduced in amplitude. The ventral root reflex was first augmented and then decreased. 3. The depolarization caused by PTX was markedly reduced when the preparation was perfused with NaCl-deficient medium. However, tetrodotoxin (10(-7) M) only slightly inhibited the depolarization. 4. In a high Ca2+ medium (3.6 mM), the time required to reach the maximum depolarization evoked by PTX was significantly prolonged. In contrast, in a low Ca2+ medium (0.9 mM), PTX caused a marked depolarization soon after application. In a Ca2+-free, Mg2+ (9.0 mM) medium, PTX caused rhythmic oscillatory potentials in both ventral and dorsal roots. 5. The potency of N-acetyl PTX was one hundredth that of the parent compound. 6. It is suggested that PTX may interfere with the stabilizing action of Ca2+ on the neuronal membrane, consequently facilitating Na+ permeability. The primary amine in the PTX molecule may be important for its pharmacological action.

Acrylamides↗
PubMed1979

[Effects of benzodiazepine derivatives on gamma-motor system in rats (author's transl)].

Effects of four benzodiazepine derivatives on gamma-activity were examined in the anesthetized rat. Diazepam and 5-(o-chlorophenyl)-1-methyl-7-nitro-1, 3-dihydro-2H-1, 4-benzodiazepin-2-one(ID-690) in a dose of 2.5 mg/kg (i.p.) showed depressant effects on gamma-activity. The depressant effects of 5.0 mg/kg (i.p.) lasted for more than 60 min. Nitrazepam had a slightly weaker effect than the above two drugs and the effect was evident after an administration of 5.0 mg/kg; the effect of 10 mg/kg(i.p.) lasted for more than 90 min. The effect of clonazepam was much weaker than effects of the other three drugs. A dose of 20 mg/kg(i.p.) was required to produce an obvious depressant action, and the effect appeared after a longer latency of about 20 min. ID 690 (5.0 mg/kg, i.p.) depressed the augmented response of the gamma-activity in response to pinna stimulation. The effect of diazepam on the augmented responses was observed with the same dose. In contrast, much higher doses of nitrazepam and clonazepam were required to induce an obvious depressant effect on the augmented gamma-activity. It is suggested that the difference in potency in depressing gamma-activity of these derivatives is one of the factors characterizing their pharmacological properties.

Animals↗
PubMed1978

Clinical evaluation of 5-hydroxy-L-tryptophan as an antidepressant drug.

Effectiveness of 5-hydroxy-L-trytophan as an antidepressant drug was studied with 59 patients with depressive symptoms using Rating Scale for Depression made by Clinico-Psychopharmacology Research Group in Japan for a preparatory step of a double blind clinical study of 5-hydroxy-L-tryptophan treatment of depression. A daily dose of 150--300 mg of 5-hydroxyl-L-tryptophan was administered for three weeks. Favorable responses were observed in 40 patients (67.8%), of whom 13 patients were markedly improved. These effects were noticed in 32 patients (80% of the improved patients) within a week of the treatment. Analysis of General Improvement Rating in the various subtypes of depressive symptoms indicated that endogenous depression and involutional or senile depression were the preferable indication of 5-hydroxy-L-tryptophan loading. The main side effects of 5-hydroxy-L-tryptophan were gastrointestinal disturbances which were minimized by the simultaneous administration of metoclopromide or trihexyphenidyl.

5-Hydroxytryptophan↗
PubMed1978

Alterations in spontaneous activity of the isolated frog spinal cord in Calcium-free environment.

Spontaneous electrical activity of the isolated frog spinal cord was examined in Ca2+-free environment. Spontaneous discharges from the ventral root altered in four distinguishable steps. The first step was an immediate increase in the rate of spontaneous discharges and the second was a gradual decrease. The third was the occurrence of rhythmical bursts, and the last, the appearance of continuous firing. The rhythmical bursts could be depressed by the addition of metabolic inhibitors (ouabain or dinitrophenol in a concentration of 5 x 10(-5) M) as well as of Ca2+-chelating agents (EDTA or EGTA in a concentration of 10(-3) M). Our results suggest that the occurrence of the rhythmical bursts requires a metabolic pumping process to redistribute Na+ and K+ across the membrane and a small amount of Ca2+ for transmitter secretion.

Animals↗