Setsuo Komura

Reexamination of the relationship between alcohol preference and brain monoamines in inbred strains of mice including senescence-accelerated mice.

The relationship between voluntary alcohol consumption and brain monoamine levels was studied in the inbred strains of C57BL/6N, C57BL/6J, A/J, BALB/cA, CBA/N, C3H/He and DBA/2cr mice; the congeneric mouse strain, B10.Br/Sg, and the senescence accelerated mouse (SAM P1, SAM P2). The C57BL strains exhibited a high alcohol preference whereas the other strains exhibited a low alcohol preference. A clear positive relationship was found between alcohol intake (g/kg/day) and brain norepinephrine level (r = 0.683, p less than 0.05), and a clear negative relationship between alcohol intake and brain serotonin level (r = -0.628, p less than 0.05). The content of brain dopamine was not clearly correlated with alcohol intake (r = -0.206, p greater than 0.05). These findings suggest that in mice voluntary alcohol preference is influenced by brain norepinephrine and serotonin levels genetically.

Conjugation of acetaldehyde with cysteinylglycine, the first metabolite in glutathione breakdown byγ-glutamyltranspeptidase

Glutathione and its metabolites were examined for reactivity to acetaldehyde. When acetaldehyde was incubated with glutathione alone, there was only a slight decrease of acetaldehyde, while an apparently equimolar reaction between acetaldehyde and free sulfhydryl was observed with the addition of γ-glutamyltranspeptidase. Cysteinylglycine, the first metabolite in the glutathione breakdown by γ-glutamyltranspeptidase, showed a rapid and equimolar reactivity to acetaldehyde and such was comparable to the reaction seen withl-cysteine ord-penicillamine. In light of the chemical structure, cysteinylglycine probably conjugates with acetaldehyde to form thiazolidinecarboxylic acid derivatives, 2-methyl-thiazolidine-4-carbonyl-glycine, and if so, the alteration of glutathione metabolism by acetaldehyde during ethanol intoxication warrants further attention.

Immunohistochemical investigation of pulmonary surfactant-associated protein A in fatal poisoning

To evaluate the immunohistochemical distribution of pulmonary surfactant-associated protein A (SP-A) in fatal poisoning in relation to the effects of drugs and poisons on respiratory function, 42 forensic autopsy cases were examined by scoring the staining intensity. The highest scores of SP-A staining, with dense granular deposits (aggregates) in the intra-alveolar space, were observed in fatalities from pancuronium bromide (muscle relaxant) injection and petroleum (butane) gas inhalation. Poisoning with organophosphate pesticides and arsenic (ingestion) showed a second grade SP-A score. However, The SP-A scores were relatively low in ethanol and sedative-hypnotic intoxication. Carbon monoxide intoxication showed a varied degree of SP-A score, and the aggregated SP-A score tended to be higher in cases of lower blood carboxyhemoglobin concentration. A varied SP-A score was also observed in methamphetamine fatalities, in which the score was relatively low in cases with a higher serum drug level. Increase of SP-A was not always associated with the intra-alveolar effusion or hemorrhages. The above-described observations suggested that the immunohistochemical score of SP-A may be a possible indication for intensity and duration of drug/poison-dependent respiratory distress.

Death caused by triazolam and ethanol intoxication.

Gas chromatography-mass spectrometry was used for the quantification of the hypnotic drug triazolam in human samples. In our case, death was attributed to triazolam and ethanol intoxication. The whole blood concentration of triazolam was 7.0 ng/ml and that of ethanol was 230 mg/dl. Based on the literature, this is the lowest triazolam concentration that has been associated with death.

Rapid postmortem changes of rat striatum dopamine, serotonin, and their metabolites as monitored by brain microdialysis

Brain microdialysis was used to monitor changes in extracellular dopamine (DA), serotonin (5-HT), and their metabolite levels in the rat striatum at death by cervical dislocation. Maximum respective 450-fold and 150-fold increases in the extracellular output of DA and 5-HT were observed within the first 30 min of death. DA and 5-HT outputs remained elevated over the following 2 h at levels about 100-fold and 50-fold above pre-death values, respectively. In contrast with monoamine outputs, the outputs of the DA metabolite, 3,4-dihydroxyphenylacetic acid (DOPAC), and the 5-HT metabolite, 5-hydroxyindoleacetic acid (5-HIAA), rapidly decreased by 10% and 20%, respectively 1 h after death. 5-Hydroxytryptophol (5-HTOL) gradually decreased after death. Before death both the extracellular DOPAC/DA and 5-HIAA/5-HT ratios were about 400; after death these ratios dropped to 0.56 and 4.0, respectively at 30 min. These observations suggested that regulation of neurotransmitter releases through the neuronal membrane and metabolisms in the rat striatum were seriously disrupted at death. This finding may be helpful in the determination of death in the field of forensic medicine.

Central monoamines and the death process time (antemortem time) during asphyxia

SummaryThe changes of the brain monoamines, norepinephrine (NE), dopamine (DA), and serotonin (5-HT), during acute asphyxia, caused by strangulation, anoxia, and drowning, were studied in the mouse.In several asphyxiated animal groups significant linear correlation was found between the level of monoamines, NE, DA, and 5-HT, and the death process times or antemortem times were r=0.50, 0.98 (P<0.05), and 0.57, respectively.It is concluded that the level of brain NE and DA increased in the mouse that died of asphyxia, and the level of 5-HT showed only an apparent decrease in anoxia groups as compared with the control group and showed a twice as high increase in drowning groups. Especially, there was a tendency that the longer the death process times or antemortem times, the higher was the level of DA.ZusammenfassungDie Konzentrationsänderung der Monoamine Norepinephrin (NE), Dopamin (DA) und Serotonin (5-HT) im Gehirn wurde während der akuten Asphyxie (Strangulation, Anoxie und Ertrinken) experimentell an Mäusen untersucht. In verschiedenen Versuchsgruppen wurde eine signifikante, lineare Abhängigkeit der Monoamin-Werte NE, DA, und 5-HT zur Länge des agonalen Stadiums beobachtet, wobei folgende Korrelationskoeffizienten errechnet wurden: r=0,50, 0,98, (P<0,05) und 0,57.Hieraus wird geschlossen, daß die Konzentration des NE und 5-HT im Gehirn bei den asphyktischen Tieren zunimmt, die das 5-HT bei den Tieren unter Anoxie abfällt, hingegen einen etwa zweifachen Anstieg bei den Tieren aufweist, die ertranken. Darüber hinaus ließ sich eine Tendenz zu höheren DA-Werten feststellen, die in Abhängigkeit zur Länge der agonalen Phase steht.

Phenotypic variation of human antithrombin III in normal plasma: Detection by isoelectric focusing

SummaryPlasma AT-III exhibits a microheterogeneous form with pIs distributed over a narrow pH range by analytical agarose gel isoelectric focusing followed by immunofixation. Three new variants, each of which was the heterozygous state between the common and each variant components, were observed in a total 370 samples from unrelated healthy donors. These variants have at least normal activities of the thrombin inactivation in the presence of heparin, and their immunological antigen concentrations in plasma are in the normal range.

Effects of ion channel blockers on rapid postmortem changes in extracellular dopamine and serotonin levels in the rat nucleus accumbens

In the present study, we used in vivo brain microdialysis to examine the effects of ion channel blockers tetrodotoxin (TTX), EGTA-free Ca2+ and verapamil on rapid postmortem changes in extracellular levels of dopamine (DA), serotonin (5-HT) and their metabolites dihydroxyphenylacetic acid (DOPAC) and 5-hydroxyindoleacetic acid (5-HIAA) in the ACC of freely moving rats. Extracellular ACC DA levels decreased following the perfusion of the three ion channel blockers in freely moving rats, and then, at death by cervical dislocation, maximum respective 220-, 60- and 90-fold increases were observed in the extracellular output of DA in animals treated with EGTA, verapamil and TTX, respectively. Also, ACC 5-HT decreased following perfusion with the three blockers in the freely moving rats, and then maximum increases of 80-, 30- and 45-fold in the extracellular output of 5-HT were observed at death in animals treated with EGTA, verapamil and TTX, respectively, compared to the baseline. Cervical dislocation-induced rapid postmortem changes were inhibited markedly by perfusion with CSF containing the CA2+ entry blocker verapamil. These observations suggested that rapid postmortem changes in ACC DA and 5-HT release were associated with the action of calcium ion channels and/or voltage gated channels in the CNS.

Fundamental studies on alcohol dependence and disposition

This article reviews some recent studies on alcohol preference, dependence, metabolism and pharmacokinetics which were mainly carried out in our department. The inbred strains of mice with genetically different alcohol drinking behavior and alcohol animal model treated with the neurotoxins, 6-hydroxydopamine and 5,7-dihydroxytryptamine, are useful for a behavioral and pharmacological approach to evaluate the contribution of specific neural systems to alcohol, drug dependence mechanism and alcohol drinking behavior. The relations between alcohol preference and some physiological conditions are reviewed. On the drug-alcohol interaction, some drugs containing the chemical group = CHONO2, antimony and methamphetamine are addressed. This article also deals with recent topics in the pharmacokinetics and pharmacodynamics of alcohol. The dose-dependency of the alcohol elimination rate, the first-pass metabolism during alcohol drinking, and the pharmacodynamic model for describing pulse rate reaction to plasma acetaldehyde are discussed.

Genetic polymorphism of white blood cell glucose dehydrogenase in Japanese

SummaryGenetic polymorphism of the glucose dehydrogenase in white cells extracts from random adult Japanese was investigated using polyacrylamide gel isoelectric focusing or agarose gel isoelectric focusing, followed by a specific zymogram technique. Three common phenotypes, which might correspond to GDH 1, GDH 2 and GDH 2-1 reported by King and Cook (1981), were observed at the p Is between pH 6.56–6.76 on the gel. No phenotypes with GDH 3 component were detected so far. The allele frequency of GDH3 may be very low among Japanese. The results of family study suggest that these phenotypes are inherited in the autosomal codominant trait. The allele frequencies were GDH1=0.522 and GDH2=0.478.