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G Zbinden

Publications and source records attributed to G Zbinden.

150 records · Page 9Linked to original sources
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[Alternative methods, the present and future].

Alternative methods are already widely used in fundamental biological research. Among 6,649 papers given at the FASEB 1989 meeting, nearly 60 p. 100 deal with experimental data obtained without the use of live animals. Alternative methods are less frequently utilized in industrial Toxicology. The reason of this discrepancy is discussed as well as the efforts made to reduce the numbers of animals for acute toxicity studies (LD 50) and cutaneous and eye tolerance. Present scientific developments as well as the possible agreement by regulatory agencies of the newly developed tests are presented. In spite of the increasing acceptance of alternative methods, large numbers of animals are still used. The reasons for this state of affairs are analysed, as well as the efforts which are made to encourage research for the replacement of animals in programs traditionally based on animal experimentation.

Animal Testing Alternatives↗
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[Neurobehavioral toxicology].

The various experimental approaches to detect and characterize neurotoxic chemicals, i.e. pathomorphology, electrophysiology, neurobiochemistry and ethology, are discussed. In recent years neurobehavioral techniques have been used widely in toxicology because of their non-invasiveness and considerable discriminative power. Advantages and disadvantages of neurobehavioral techniques are discussed. Two approaches, namely development of animal models that imitate human neurobehavioral disorders and diseases, and measurement of basic elements of behavior are presented. Examples are given to demonstrate how modern computerized behavioral techniques are able to assess various basic elements of behavior. Through microanalysis of the data detailed information on behavioral effects of various neurotoxins can be obtained. These concepts are demonstrated with experiments using ethanol, caffeine and methylmercury as reference substances. Many more chemical substances must be tested with these techniques to obtain the necessary information for predictive conclusions for humans.

Animals↗
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Correlation of telemetered heart rate and locomotor behavior in cyclazocine treated rats.

Two experiments were performed to verify the validity of a biotelemetry system for 24 hour recording of heart rate (HR) of rats in behavioral toxicology. As test substance the hallucinogenic drug cyclazocine was used at various dose levels (0.1, 0.75, 1.5 and 3.0 mg/kg SC). In a first experiment, female rats were tested in their home cage. It was found that HR was altered by cyclazocine during the four hours following drug injection. This alteration was biphasic: immediately after injection, when control HR was high, cyclazocine lowered HR. In contrast, one hour after the injection, when control HR was low, cyclazocine increased HR. The duration of this increase of HR was dose-dependent, while the magnitude was not. In a second experiment male rats were tested in a residential maze: simultaneously to the rat's HR, locomotor activity was recorded. The results of the first experiment were confirmed and extended to males as well as to a different environmental situation. The additional behavioral data showed a different aspect of cyclazocine action: 0.75 mg/kg initially decreased and later increased activity while 3.0 mg/kg first did not alter activity and later increased it, leading to a dissociation between HR and activity. The findings demonstrate that recording of HR adds a new dimension to the data obtained in conventional behavioral tests. The results are discussed with regard to behavioral and neurochemical effects of the drug.

Animals↗