Alternative acute inhalation toxicity testing by determination of the concentration-time-mortality relationship: Experimental comparison with standard LC50 testing

A new design for acute inhalation toxicity testing was evaluated and compared with results obtained according to OECD guideline 403. The new design consists of a range-finding test, which is compatible with a conventional limit test, and can be followed by determination of a concentration-time-mortality relationship, enabling calculation of LC50...

Two-compartment model for rabbit skin organ culture

A new method was developed for rabbit skin organ culture. In a two-compartment model, skin discs were cultured on a Millicell-HA insert unit with a microporous membrane which allows transport of culture medium via the dermis into the epidermis, whereas the epidermal side remains free of direct contact with culture medium. In this relatively...

A neurofunctional test battery for evaluating the effects of long-term exposure to chemicals

Induction of hyperplasia in the bladder epithelium of rats by a dietary excess of acid or base: Implications for toxicity/carcinogenicity testing

In previous studies we observed an increased incidence of hyperplasia in the epithelium of the urinary bladder of rats fed cereal-based stock diet supplemented with 6% monosodium glutamate (MSG) for 3 months. Hyperplasia was not enhanced, however, when 6% MSG was fed in a purified casein diet. Further studies have been conducted to identify the...

The long-term study in rodents for identifying carcinogens: Some controversies and suggestions for improvements

Despite increasing standardisation and international harmonisation of the long-term carcinogenicity study in rodents there are still areas of controversy such as high-dose selection, duration of the test period, combining or not combining the chronic toxicity and the carcinogenicity study, the use of historical control data, conditions for...

Significance of the dog as 'second animal species' in toxicity testing for establishing the lowest 'no-toxic-effect level'

The toxicity data of 66 compounds adequately tested in the rat (as 'prime animal species') and in the dog (as 'second animal species') were studied to find out for how many of these compounds the study in dogs led to a lower 'no-toxic-effect level' (NTEL) than that found in the rat. From a quantitative point of view such information would...

Relevance of parameters related to fertility and reproduction in toxicity testing

Toxicity data of 37 compounds tested in both a subchronic study and one or more studies focused on reproduction were evaluated to obtain information on the significance of fertility and reproduction parameters in setting no-effect levels (NEL). It appeared that a) the test system aimed at reproduction and development was more sensitive than the...