Yuko Fukui

A systematic regional study of brain salsolinol levels during and immediately following chronic ethanol ingestion in rats

Regional contents of salsolinol and catecholamines in the brain of normal and ethanol-treated rats were studied. Male Sprague Dawley rats were given ethanol solution as sole drinking fluid for 3, 4, 5 or 6 months. Salsolinol determined by gas chromatography mass spectrometry was found to be present in the hypothalamus and the striatum of control rats. The levels of salsolinol in these regions increased significantly by long-term ethanol drinking and rapidly decreased to control levels following its removal. Salsolinol levels in other regions of rat brain were extremely low or negative and unaltered upon chronic ethanol treatment. In ethanol-treated rats the hypothalamic salsolinol, although generally higher than in the striatum, increased along with the ethanol exposure, whereas the striatal salsolinol was constant during those periods of study. Brain dopamine (DA) and norepinephrine contents remained unaltered during and immediately after chronic ethanol treatments. No correlation of salsolinol levels with DA contents or blood ethanol concentrations was observed. The occurrence of salsolinol in selected areas of rat brain with lack of changes in catecholamine level but as a result of an in vivo formation by long-term ethanol drinking was considered to be due to an alteration of acetaldehyde metabolism in the liver and brain.

Detection of Δ9-THC in saliva by capillary GCECD after marihuana smoking

Abstract A method is described for the determination of Δ 9 -tetrahydrocannabinol ( Δ 9 -THC) in the saliva by the use of a combination of moving-precolumn injector and glass capillary gas chromatograph with electron capture detector (GCECD). There were no interfering peaks due to impurities around the peak of pentafluoropropyl derivative of Δ 9 -THC ( Δ 9 -THC-PFP). This GCECD method was linear over the range of 5–200 ng/ml of Δ 9 -THC-PFP. The lower detection limit was approximately 1 ng/ml. Δ 9 -THC content in the saliva after experimental marihuana smoking was measured by this method. It was demonstrated that for at least 4 h after smoking the level of Δ 9 -THC was sufficient for detection.

Quantitation of cocaine, benzoylecgonine and ecgonine methyl ester by GC-CI-SIM after Extrelut extraction

A method of gas chromatography-chemical ionization selected ion monitoring (GC-CI-SIM) is described for the determination of cocaine, benzoylecgonine and ecgonine methyl ester in biological materials using an Extrelut extraction technique. Recoveries of cocaine, benzoylecgonine and ecgonine methyl ester by this technique were 95, 81 and 97%, respectively. The method uses cocaine-d5, benzoylecgonine-d5 and lidocaine as internal standards, and isobutane as reagent gas for chemical ionization. Sensitivity of the method proved to be 1 ng/ml for cocaine and benzoylecgonine, and 10 ng/ml for ecgonine methyl ester when used in a 10-ml urine sample. With animal experiments, ecgonine methyl ester as well as benzoylecgonine was confirmed as a major metabolite of cocaine.

A new method for detecting diatoms in human organs

A new method for diatom detection is described. It includes an ultrasonic irradiation procedure with the use of a tissue solubilizer. The method is easy to carry out and is less time-consuming than previous techniques.

Gas chromatographic determination for forensic purposes of petroleum fuel inhaled just before fatal burning

The determination of petroleum fuel in the blood of burned bodies was carried out by three different gas chromatographic procedures. Seven components of gasoline (isopentane, n-pentane, 2-methylpentane, benzene, 2-methylhexane, 3-methylhexane and toluene) and five of kerosene (xylene, C9H20, mesitylene, pseudocumene and C11H24) were chosen as indicators with a coefficient of variation of 5-24%. The methods were applied to four autopsy cases with a relatively low carboxyhaemoglobin (HbCO) content. When gasoline exposure had occurred, the blood concentrations determined were almost identical whatever the components selected. Great variations in the components determined were found after kerosene exposure, and hydrocarbons greater than or equal to C14 were hardly inhaled by the victims. A higher content of fuel in the left than in the right ventricular blood observed in the autopsy cases suggests fuel inhalation just before death. The same phenomenon was also observed in the content of blood HbCO. Determinations of petroleum fuel and HbCO in both the right and left ventricular blood would be useful for the forensic diagnosis on burned bodies with a low HbCO content.

Effects of methamphetamine on rat embryos cultured in vitro

Wistar rat embryos were explanted on day 10.5 of gestation and exposed in vitro to methamphetamine (MAMP) at a concentration of 0.1, 0.2, 0.4, 0.6, or 0.8 mM for 24 h, and the direct teratogenic effects of the drug on rat embryos were examined. The viability of cultured embryos was not affected by the MAMP treatment. The yolk sac diameter was reduced at MAMP concentrations of 0.6 and 0.8 mM. The crown-rump length and the somite number of the embryos decreased significantly and dependently on the MAMP concentrations at 0.4-0.8 mM. The protein content was also significantly reduced at 0.4-0.8 mM. The developmental score was decreased in a concentration-dependent manner. The frequency of malformed embryos significantly increased at 0.6 and 0.8 mM. The malformations induced in treated embryos included microcephaly, neural tube defects, incomplete rotation of the body axis, and tortuous spinal cord. Abnormal histological changes such as derangement and necrosis in the neuroepithelial tissue were observed in embryos exposed to high concentration of the drug. Our results revealed the direct embryotoxic and teratogenic effects of MAMP in the rat.

Chromophoric labeling of cannabinoids with 4-dimethylaminoazobenzene-4'-sulfonyl chloride

A simple and sensitive assay for the cannabinoids is presented using a dabsylation procedure. Dabsyl derivatives of delta 9-tetrahydrocannabinol (delta 9-THC) and cannabinol (CBN) were prepared by reacting with 4-dimethylaminoazobenzene-4-sulfonyl chloride (dabsyl chloride) in acetone in the presence of sodium carbonate-sodium bicarbonate buffer (pH 10). Crystalline dabsylcannabinoids gave intense absorption in the visible region. With these derivatives, analysis by thin-layer chromatography (TLC) and high performance liquid chromatography (HPLC) were tested. These techniques gave good separation and nanogram detection of dabsyl-THC and -CBN by using n-hexane-ethyl acetate-diethylamine (20:5:1) for TLC and MeOH--H2O (95:5) at 450 nm for HPLC.

Metabolic interaction between toluene and ethanol in rabbits

The metabolic interaction of toluene and ethanol was studied in male rabbits having received ethanol (26.0 mmol/kg PO), toluene (5.4 mmol/kg PO) or both. Compared with ethanol alone, toluene given 2 h after ethanol caused a significantly higher and more prolonged concentration of blood alcohol. A similar trend of blood alcohol was observed at the later stage with toluene given prior to ethanol. On the other hand, with simultaneous doses of the two substances, the blood toluene concentration was higher for the first 15–30 min than the ethanol control and the urinary excretion of hippuric acid, a main metabolite of toluene, was markedly decreased for the first 2 h. The blood ethanol in this group, on the contrary, was reduced until 1 h after administration. These results indicate that toluene and ethanol act reciprocally as competitive inhibitors in their metabolism after single administrations.

Derivative spectrophotometric studies on cytotoxic effects of carbon monoxide

Characteristics of cytochrome oxidase prepared from hearts of Sprague-Dawley male rats were studied with the use of the fourth derivative spectrophotometry in respect to the cytotoxic effects of carbon monoxide (CO). CO-exposed rats tended to show lower specific activities of cytochrome oxidase than control and recovered rats. Moreover, there was a significant difference in the fourth derivative spectral features of the enzyme: CO-exposed groups indicated peaks at 412 nm in the spectra while controls at 408 nm. This spectral difference seemed to reflect specific effect of CO on cytochrome oxidase, though such trace remained for not more than a day after death.

Acute effects of ethanol and acetaldehyde on plasma phosphate level

Oral administration of ethanol in a dose of 65 mmol kg−1 produced marked change of plasma phosphate level in rabbits. Hypophosphataemia was observed for the first 2 h after administration followed by significant increase of plasma phosphate at 5 h. Hypophosphataemia did not appear when ethanol was given to the rabbits pretreated with pyrazole. When animals were injected with disulfiram in advance, the duration of hyperphosphataemia due to ethanol was prolonged. Administration of acetaldehyde at a dose of 1.5 mmol kg−1 produced hyperphosphataemia. In this study, plasma phosphate was not associated with change in calcium level. These results suggest that the hypophosphataemia observed was related to the metabolic process of ethanol utilizing alcohol dehydrogenase, and that acetaldehyde, a metabolite of ethanol, might induce the hyperphosphataemia in the animals.