Self-organization and anomalous diffusion at the early onset of dissipative electromagnetic drift-wave advection in a gravitational field.
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Journal Article↗
Biomedical subjects
A Hirose
Publications and source records attributed to A Hirose.
Characterization of the putative anxiolytic SM-3997 recognition sites in rat brain.
In order to clarify the mechanism of action of the putative nonbenzodiazepine anxiolytic SM-3997 [3a alpha,4 beta,7 beta,7a alpha)-Hexahydro-2-(4-(4-(2-pyrimidinyl)-1- piperazinyl)-butyl)-4,7-methano-1H-isoindole-1,3 (2H)-dione dihydrogen citrate), in vitro binding studies with radiolabeled compound were performed. 3H-SM-3997 bound rapidly, reversibly and in a saturable manner with high affinity to rat brain hippocampal membranes (Kd = 9.4 nM, Bmax = 213 fmol/mg protein). This specific binding was displaced by 5-hydroxytryptamine (5-HT) and related compounds. Especially, 8-OH-DPAT, a 5-HT-1A selective agonist, bound with the highest affinity to these binding sites. 3H-SM-3997 binding, however, was not displaced by a variety of other neurotransmitters, neuropeptides and some other drugs. EDTA and physiological concentration of Na+ inhibited this specific binding, but several divalent cations, Mn2+, Ca2+ and Mg2+, enhanced this binding. GTP decreased the affinity of these binding sites for 3H-SM-3997 without changing the number of binding sites, but GMP and ATP did not influence 3H-SM-3997 binding. Furthermore, 3H-SM-3997 bound with marked regional selectivity to hippocampal membranes. These characteristics and the regional distribution of 3H-SM-3997 binding sites were very similar to those of 3H-8-OH-DPAT binding sites (5-HT-1A receptors). Therefore, these results indicate that SM-3997 binds selectively and with high affinity to 5-HT-1A receptors in rat brain and may be an agonist.
8-Hydroxy-2-(di-n-propylamino)tetralin↗
Interaction of SM-3997 with serotonin receptors in rat brain.
The propensity of SM-3997 to displace 3H-ligands was tested in vitro in a number of receptor-binding assays. SM-3997 possessed a high affinity towards 5-HT1A receptors, low affinity towards dopamine (D2) and 5-HT2 receptors, and no affinity towards benzodiazepine (BZ), GABA, 5-HT1B and adrenergic receptors. Moreover, SM-3997 facilitated neither 3H-flunitrazepam binding nor 3H-muscimol binding. These results suggest that the action of SM-3997 may be mediated via central 5-HT1A receptors but not the BZ-GABA receptor complex.
Animals↗
Inhibitory effects of L-threo-DOPS, an L-noradrenaline precursor, on locus coeruleus-originating neurons in the caudate nucleus.
Electrophysiological studies using reserpine-treated cats were carried out to elucidate the effects of L-threo-3,4-dihydroxyphenylserine (L-threo-DOPS) on the noradrenergic pathway from the locus coeruleus (LC) to the caudate nucleus (CN) neurons, which were activated by iontophoretically applied bromocriptine, a dopamine D-2 receptor agonist. In the CN neurons, glutamate-induced firing was inhibited by iontophoretic application of noradrenaline, but not by repetitive stimulation of the LC or iontophoretically applied L-threo-DOPS. After intraventricular administration of L-threo-DOPS, however, LC stimulation inhibited the glutamate-induced firing. These results suggest that L-noradrenaline that was produced from the conversion of L-threo-DOPS inhibited the CN neurons which possess dopamine D-2 receptors.
Animals↗
[Dye coupling between the choroidal melanocytes].
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Animals↗
Multiple detection system for the high-resolution microcolumn size-exclusion chromatographic separation of proteins with a slurry-packed capillary column.
A multiple (triple) detection system with one detector and recorder each was developed for the high-resolution size-exclusion chromatographic separation of proteins with a slurry packed capillary column. Fused-silica capillary columns of length 1, 2.5 and 6 m and I.D. 0.26 mm were connected in this order by joining each end of the shorter column to the top of the longer column through flow-through cells installed side-by-side on a cell block in the detector. By this means it was possible to record the chromatograms three times with one injection. This system is convenient for comparing the chromatograms obtained with different plate numbers and for effecting very high-resolution separations.
Chromatography, Gel↗
Effects of long-term administration of clofibric acid on stearoyl-CoA desaturase, 1-acylglycerophosphorylcholine acyltransferase and fatty acyl composition of microsomal phosphatidylcholine in rat liver.
Long-term effects of p-chlorophenoxyisobutyric acid (clofibric acid) on inductions of stearoyl-CoA desaturase and 1-acylglycerophosphorylcholine (1-acyl-GPC) acyltransferase, and on changes in fatty acyl composition of microsomal lipid in rat liver were studied. Male rats were fed clofibric acid at a dietary concentration of 0.25% for 2 or 22 weeks. Inductions of stearoyl-CoA desaturase and 1-acyl-GPC acyltransferase lasted throughout the long-term treatment and were the same as those of either young or aged rats which were treated with clofibric acid for 2 weeks. The long-term treatment of rats with clofibric acid scarcely affected components of stearoyl-CoA desaturation system other than terminal desaturase. In accordance with the induction of stearoyl-CoA desaturase, the increase in the proportion of octadecenoic acid in hepatic lipid lasted throughout the 22-week treatment. In the case of both of the long-term treatment and the short-term treatment of rats, the increase in the proportion of octadecenoic acid in microsomal phosphatidylcholine was due to the marked increase in the proportion of octadecenoic acid in position 2, but not position 1, of phosphatidylcholine. These changes in fatty acyl composition of phosphatidylcholine were not due to the alteration of the content of phosphatidylcholine in liver.
1-Acylglycerophosphocholine O-Acyltransferase↗
Pharmacological properties of SM-3997: a new anxioselective anxiolytic candidate.
Pharmacological properties of SM-3997 (3a alpha,4 beta,7 beta,7a alpha-hexahydro-2-(4-(4-(2-pyrimidinyl)-1- piperazinyl)-butyl)-4,7-methano-1H-isoindole-1,3(2H)-dione dihydrogen citrate) have been examined in rats and mice. SM-3997 showed a dose-related anticonflict activity in rats in a water lick conflict paradigm, and it had no effect on water consumption in a spontaneous water drinking test. The potency of SM-3997 appeared to be equal to that of buspirone and about one-half that of diazepam. No tolerance to the anticonflict activity of SM-3997 was observed following 5 and 10 consecutive days of treatment. Unlike diazepam, SM-3997 had no anticonvulsant effect and had very weak muscle relaxant and hypnotic effects. On the other hand, SM-3997 and buspirone exhibited dopamine antagonistic action, although the potency of SM-3997 was less than one fourth that of buspirone. These results show that SM-3997 is a new anxioselective anxiolytic agent which is weaker than buspirone in the dopaminergic neuron system.
Anesthesia↗
[Quantitative study of diffuse increased 99mTc-methylene diphosphonate accumulation of both kidneys].
Patients with diffuse increased accumulation in both kidneys on 99mTc-MDP bone scintigram were evaluated quantitatively. Among 1,100 cases, 7 (0.63%) showed this finding. The accumulation density ratios of kidneys/lumbal vertebra in A/D exchanged images of these patients were compared with control group, so that these ratios of patient group were higher than control group statistically. In conclusion, the accumulation density ratio was made the index of diffuse increase accumulation in both kidneys on 99mTc-MDP bone scintigram.
Adult↗
[Prevalence of oral diseases in dental students].
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Cross-Sectional Studies↗
[Comparative study on the pre-and postoperative myelogram in anterior lumbar surgery].
In order to investigate the change of the dural tube and radicular sheath after anterior surgery, metrizamide myelography was performed in 32 cases of lumbar disc herniation, 12 of spondylolytic spondylolisthesis, and 9 of degenerative spondylolisthesis. Postoperative myelography was performed 3 to 8 weeks after surgery. The improved postoperatively in radicular sheath was 67% of the cases of disc herniation, 60% of spondylolytic spondylolisthesis, and 36% of degenerative spondylolisthesis. Postoperatively, no abnormal findings of dural tube were observed in the lateral view in 80% of the cases of disc herniation, and 78% of those of spondylolytic spondylolisthesis. Improvement of myelographic findings of the dural tube seemed to be related to the clinical results of surgery for disc herniation and degenerative spondylolisthesis. These facts indicated that anterior surgery is a reliable procedure to obtain surgical decompression and favorable clinical results.
Adolescent↗
Alterations by peroxisome proliferators of acyl composition of hepatic phosphatidylcholine in rats, mice and guinea-pigs. Role of stearoyl-CoA desaturase.
Rats, mice and guinea-pigs were administered p-chlorophenoxyisobutyric acid (clofibric acid) or 2,2'-(decamethylenedithio)diethanol (tiadenol). The treatments of rats and mice with either clofibric acid or tiadenol increased markedly the activities of stearoyl-CoA desaturase, palmitoyl-CoA chain elongation, 1-acylglycerophosphate (1-acyl-GP) acyltransferase and 1-acylglycerophosphocholine (1-acyl-GPC) acyltransferase, but not 2-acylglycerophosphocholine (2-acyl-GPC) acyltransferase in liver microsomes. The treatment of guinea-pigs with clofibric acid did not cause any change in the activities of these enzymes. The treatment of guinea-pigs with tiadenol caused a slight, but significant, increase in the activities of 1-acyl-GP acyltransferase and 1-acyl-GPC acyltransferase. The treatment of rats and mice with either clofibric acid or tiadenol increased markedly the proportion of 18:1 and decreased greatly the proportion of 18:0 in liver microsomal phosphatidylcholine. However, there is a considerable difference in the effects of the two peroxisome proliferators on the composition of polyunsaturated fatty acids in phosphatidylcholine between rats and mice. The treatment of guinea-pigs with either of the two peroxisome proliferators caused no change in acyl composition of phosphatidylcholine. The possible role of stearoyl-CoA desaturation in the regulation of acyl composition of phosphatidylcholine was discussed.
Acyl Coenzyme A↗
Inducing effects of clofibric acid on 1-acylglycerophosphorylcholine acyltransferase in kidney and intestinal mucosa of rats.
Administration of p-chlorophenoxyisobutyric acid (clofibric acid) markedly increased the activity of microsomal 1-acylglycerophosphorylcholine (1-acyl-GPC) acyltransferase in kidney, intestinal mucosa and liver, but not in brain, heart, lung, spleen, testis or skeletal muscle. In both kidney and liver, a marked dose-dependent increase in the activities of both microsomal 1-acyl-GPC acyltransferase and peroxisomal beta-oxidation was observed. In the rats treated with clofibric acid at a relatively low dose, the increase in the activity of 1-acyl-GPC acyltransferase in kidney was more marked than that in liver. The extent of the relative increase in the activity of 1-acyl-GPC acyltransferase to the activity of peroxisomal beta-oxidation in kidney was more marked than that in liver. The increased activity of 1-acyl-GPC acyltransferase in both kidney and liver lasted throughout the 8-week treatment period of rat with clofibric acid.
1-Acylglycerophosphocholine O-Acyltransferase↗
Reversal of the reserpine-induced ptosis by L-threo-3,4-dihydroxy-phenylserine (L-threo-DOPS), a (-)-norepinephrine precursor, and its potentiation by imipramine or nialamide.
The effect of L-threo-DOPS on the reserpine-induced ptosis in mice and its modification by imipramine, a norepinephrine (NE) uptake inhibitor, or nialamide, a monoamineoxidase inhibitor, were studied. Intraperitoneal (i.p.) injection of L-threo-DOPS (800 mg/kg) significantly reduced the severity of the ptosis. This reversal of the ptosis by L-threo-DOPS was markedly potentiated by i.p. injection of either imipramine (2.5 mg/kg) or nialamide (30 mg/kg). Response to L-threo-DOPS was also significantly potentiated by intracerebroventricular (i.c.v.) injection of imipramine (10 micrograms). On the other hand, this treatment with imipramine (10 micrograms, i.c.v.) also significantly potentiated the reversal of the ptosis by NE (20 micrograms, i.c.v.), but the reversal by the subcutaneous (s.c.) injection of NE (1 and 3 mg/kg) was not affected. Reserpine (5 mg/kg, i.p.) markedly decreased the brain content of NE in mice, whereas L-threo-DOPS (400 mg/kg, i.p.) slightly restored it. Moreover, by the pretreatment with nialamide (30 mg/kg, i.p.), L-threo-DOPS produced a significant increase in the brain content of NE in reserpine-treated mice. These results suggested that L-threo-DOPS was capable of reversing the reserpine-induced ptosis due to the formation, at least in part of (-)-NE at the synaptic sites of central noradrenergic neurons.
Animals↗
Effect of clofibric acid on the molecular species composition of diacyl glycerophosphocholine of rat liver microsomes.
The effect of administering p-chlorophenoxyisobutyric (clofibric) acid to rats on the molecular species composition of diacyl-glycerophosphocholine (GPC) of rat liver microsomes was studied. Microsomal choline glycerophospholipids were converted to 1,2-diradyl-3-acetylglycerol and were separated into molecular species by reverse-phase high performance liquid chromatography. Diacyl-GPC consisted of 17 different molecular species. The predominant species were arachidonoyl derivatives, such as 18:0-20:4 (22.2% of the total) and 16:0-20:4 (22.0%). Administration of clofibric acid to rats caused a marked increase in 16:0-18:1 species of diacyl-GPC from 8% to 30%, making these the predominant species of diacyl-GPC in clofibric acid-fed rats. Also, a significant decrease (50% of controls) in 18:0-18:2 and 18:0-20:4 species was observed, whereas the decrease in molecular species containing 16:0 at the 1-position such as 16:0-18:2 and 16:0-20:4 was small (approximately 85% of control). The results show that clofibric acid caused marked changes in the molecular species composition of diacyl-GPC. The participation of 1-acyl-GPC acyltransferase and stearoyl-CoA desaturase in the regulation of the molecular species composition of diacyl-GPC is discussed.
Acyltransferases↗
Role of stearoyl-CoA desaturase and 1-acylglycerophosphorylcholine acyltransferase in the regulation of the acyl composition of phosphatidylcholine in rat liver.
The role of stearoyl-CoA desaturase and 1-acylglycerophosphorylcholine (1-acylGPC) acyltransferase in regulating acyl composition of microsomal phosphatidylcholine was investigated in rat liver, using rats in five different kinds of physiological state: clofibric acid-fed rats, diabetic rats, insulin-treated diabetic rats, starved rats and starved-refed rats. There was a reverse linear correlation between 18:1 and 18:2 in the C-2 position, and a similar correlation was found between 18:1 and 18:2 in microsomal free fatty acids. The proportion of 18:1 or 18:2 in the C-2 position of phosphatidylcholine correlated with the proportion of the respective fatty acids in microsomal free unsaturated fatty acids which could be incorporated effectively, except for the group of clofibric acid-fed rats. In this group alone, 1-acylGPC acyltransferase was induced markedly. The proportion of 18:1 in microsomal free fatty acids correlated well with the activity of stearoyl-CoA desaturase. The physiological significance of stearoyl-CoA desaturase and 1-acylGPC acyltransferase was discussed in relation to the regulation of the acyl composition of phosphatidylcholine.
1-Acylglycerophosphocholine O-Acyltransferase↗
Effects of finite ion Larmor radius on high-n ballooning instability in tokamaks.
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Journal Article↗
Benzodiazepines and their metabolites: relationship between binding affinity to the benzodiazepine receptor and pharmacological activity.
Experiments were carried out to study the relationship between binding affinity to the benzodiazepine receptor and pharmacological activity, especially anti-anxiety activity, of clinically useful benzodiazepines. In the in vitro experiments, fludiazepam showed the highest affinity to the benzodiazepine receptor with 4 times more potency than that of diazepam, which paralleled the in vivo activity. Diazepam and nimetazepam also bound with high affinities as expected from their in vivo activities. On the contrary, medazepam and cloxazolam showed extremely low affinities and oxazolam showed no affinity, although they showed moderate in vivo activity. However, their metabolites were found to have both high affinity and in vivo activities. These results strongly suggest that in the case of medazepam, cloxazolam and oxazolam, their metabolites may bind to receptor sites in the brain and then elicit pharmacological action. This conclusion was supported by the fact that a good correlation between the binding affinity and the anti-anxiety activity of the tested compounds was observed.
Animals↗