Search results for "trains"

Interaction of uridine with GABA binding sites in cerebellar membranes of the rat

1983

The effect of uridine, a postulated anticonvulsant agent, on GABA receptors has been investigated. Uridine inhibits [3H]GABA binding to rat cerebellar buffer-washed membranes. Pretreatment of the membranes with Triton X-100 increases the effect of uridine on GABA-binding. The Scatchard analysis reveals that both high and low affinities of GABA for its receptors are affected by 1 mM uridine, while the apparent number of binding sites remains unchanged. The ability of uridine to interact competitively with GABA binding sites, also examined by the Lineweaver-Burk analysis, suggests a possible mechanism of action of this anticonvulsant agent, so including it among those compounds characterized …

Lateral differences in GABA binding sites in rat brain.

1988

An asymmetric distribution of GABA binding sites was found in the cerebral cortex, hippocampus, cerebellar hemispheres, striatum, and thalamus. Higher levels of [3H]GABA binding were observed in the left-side of most brain areas and in a greater percentage of adult rats, but the opposite asymmetry was found in the thalamus. A similar left-right difference in cerebral hemispheres was also found in five day-old rats, suggesting the genetic predetermination of asymmetry.

Dynamics of the localization of drug metabolizing enzymes in tissues and cells.

1984

Increased acetone exhalation induced by metabolites of halogenated C1 and C2 compounds.

1982

Rats were exposed, in a closed desiccator jar chamber, to concentrations of various halogenated C1 and C2 compounds at which the metabolizing capacities were saturated (Vmax conditions). Within the exposure period of 50 h concentrations of the xenobiotic and of exhaled acetone were monitored in the gas phase of the system. The quantitative extent of acetone exhalation was dependent on the individual compound examined. Acetone exhalation was stimulated in presence of vinyl chloride, vinyl bromide, vinyl fluoride, vinylidene fluoride, cis- and trans-1,2-dichloroethylene, trichloroethylene, perchloroethylene, methylene chloride, chloroform, carbon tetrachloride and 1,1,2-trichloroethane. No st…

Inhalation pharmacokinetics based on gas uptake studies. IV. The endogenous production of volatile compounds.

1983

A pharmacokinetic description of production, distribution and metabolism of endogenous volatile compounds is presented. This description uses the "gas uptake model" of a closed recirculated atmosphere in which experimental animals are exposed. As an example, the production rates of acetone, under different conditions of stimulation by xenobiotics, are calculated from published experimental data. The theoretical descriptions may serve as a basis for treating the problem of hydrocarbon exhalation in toxicological experiments with compounds eliciting lipid peroxidation.

Covalent DNA adducts formed in mouse epidermis by benzo(g)chrysene

1996

The metabolic activation in mouse skin of benzo[g]chrysene (B[g]C), a moderately carcinogenic polycyclic aromatic hydrocarbon (PAH) present in coal tar, was investigated. Male Parkes mice were treated topically with 0.5 micromol B[g]C and DNA was isolated from the treated areas of skin at various times after treatment and analysed by 32P-post-labelling. Seven major adduct spots were detected, at a maximum level of 6.55 fmol adducts/microg DNA. Mouse skin treated with the PAH benzo[c]phenanthrene (B[c]Ph) gave a total of 0.24 fmol adducts/microg DNA. B[g]C-DNA adducts persisted in skin for at least 3 weeks. Treatment of mice with 0.5 micromol of the optically pure putative proximate carcinog…

Comparative tumorigenicity of picene and dibenz[a,h]anthracene in the mouse

1990

The carcinogenic activity of the two polycyclic aromatic hydrocarbons (PAHs), picene (benzo[a]chrysene) and dibenz[a,h]anthracene (DBA), was determined in NMRI mice by five different experimental protocols in order to find out if picene is a carcinogen as predicted by recent quantum mechanical calculations in contrast to earlier observations which could not confirm any carcinogenic activity of picene. Single s.c. treatment of adult mice with picene or DBA (308 nmol/animal, each) led to the formation of fibrosarcomas in 63.3% of treated animals regardless of the PAH used. Chronic epicutaneous application of both PAHs (total dose 1.36 mumol) to the back of mice resulted in the development of …

Metabolism of 3-hydroxychrysene by rat liver microsomal preparations

1990

3-Hydroxychrysene, a metabolite of the polycyclic aromatic hydrocarbon (PAH) chrysene, was metabolised by rat liver microsomal preparations obtained from Arochlor 1254-pretreated rats. Eight major metabolites were isolated by high performance liquid chromatography and characterised by u.v. spectroscopy and a variety of mass spectrometric techniques. The metabolites were unambiguously identified as 9-hydroxy-trans-1,2-dihydroxy-1,2-dihydrochrysene and 9-hydroxy-r-1,t-2,t-3,c-4-tetrahydroxy-1,2,3,4-tetrahydrochrysene and tentatively identified as 3-hydroxy-trans-5,6-dihydroxy-5,6-dihydrochrysene (since chrysene is a symmetrical molecule the 3- and 9-positions are equivalent), 9-hydroxy-trans-…

Interaction of morphine and haloperidol on agonistic and motor behaviors of male mice.

1997

To further clarify the interaction between opioid and dopaminergic systems, the effects of simultaneous administration of morphine hydrochloride (1.25 or 2.5 mg/kg) and haloperidol (0.1 mg/kg) on aggressive behavior of male mice were explored. Isolated male mice (experimental animals) were confronted in a neutral area with anosmic, group-housed consepecifics (standard opponents) 30 min after injection of both compounds, and aggression was evaluated by estimation of times allocated to 11 different behavioral categories. In the first experiment (which functioned as a pilot study), the two doses of morphine were explored. In the second one, incorporating a more complete experimental design, on…

Gender differences in escape-avoidance behavior of mice after haloperidol administration.

1993

Gender differences in the disruptive effects of haloperidol on some reinforced behaviors have been observed in different species. However, the inhibitory action of haloperidol on the acquisition and performance of escape-avoidance behavior has only been investigated in male subjects. The present experiment was designed to investigate possible gender differences in the effects of haloperidol on the initial phase of an escape-avoidance learning task. Male and female mice of the OF1 strain were given a single training session in a shuttle-box. Thirty minutes prior to the behavioral test, mice were injected IP with haloperidol (0.25 mg/kg) or physiological saline (10 ml/kg). Latencies of escape…