An exchange assay for the cytoplasmic glucocorticoid receptor in the liver of the rat

Cytosolic receptor for glucocorticoids can exist in either the free or bound form; assays now in use measure only the free form. In order to assay the total glucocorticoid receptor content of rat liver, free plus bound, we have developed an exchange assay wherein specifically bound [³H]dexamethasone is shown to be a valid measure of receptor in the presence of high concentrations of corticosterone. The exchange between [³H]dexamethasone and corticosterone is able to proceed because, under the conditions of the assay, corticosterone is almost completely metabolized.     

Considering human toxicity as an impact category in life cycle assessment

Characterization of toxic chemicals with relevance to human exposure does normally not belong to Life Cycle Assessments (LCA) and is still a topic of research. The concept of hazard potential classes proposed in this paper is primarily based on threshold limit values that are considered to be a measure of the severity of potential effects. In the absence of threshold limit values the R-phrases of the ordinance of dangerous substances are used. Substances are assigned to five hazard potential classes (A to E). Potentially dangerous chemicals are identified and substances of low toxicological relevance are excluded from further evaluation. The location where a probable exposure might occur (indoor versus outdoor) and inter-media transport of substances is considered. The product comparison is based both on the results of the proposed “semi-quantitative screening method” and on toxicological expert knowledge.