Expression of cytochrome P450 4A mRNA in mouse lung: effect of clofibrate and interleukin-1beta.

Cytochromes P450 4A (CYP4A) metabolize arachidonic acid into hydroxyeicosatetraenoic acids (HETEs) that exhibit potent actions on airway smooth muscle tone. In the lung, modifications in CYP4A expression and HETEs production could thus contribute to alterations in airway reactivity. We characterized expression of CYP4A in the lung of BALB/c mice, and studied its regulation by the CYP4A inducer, clofibrate and by the pro-inflammatory and asthma-associated cytokine, interleukin-1beta (IL-1beta).

Increased expression and decreased activity of cytochrome P450 1A1 in a murine model of toluene diisocyanate-induced asthma.

In the lung, cytochromes P450 (CYP) may be affected by inhaled pollutants. In a previous study, we showed that acute inhalation of toluene diisocyanate (TDI), a low molecular weight chemical known to cause occupational asthma, decreased CYP2B1 expression in rat lung. In the present work, we investigated the effect of TDI in a murine model of TDI-induced asthma.

Inhalation of toluene diisocyanate affects cytochrome P450 2B1 expression in rat lung.

In the lung the expression of xenobiotic-metabolizing enzymes such as cytochromes P450 (CYP) and glutathione S-transferases (GST) may be affected by inhaled pollutants. Toluene diisocyanate (TDI) is a highly volatile chemical compound known to induce a wide array of diseases in workers exposed to vapors or sprays, including respiratory allergy and asthma. We investigated the effect of inhaled TDI on expression of CYP 1A1, 2B1, 2E1, and 3A1 and of alpha-, mu-, and pi-GST in rat lung.

Effect of toluene diisocyanate and its corresponding amines on viability and growth of human lung fibroblasts in culture.

Toluene diisocyanate (TDI) is a highly volatile chemical known to cause occupational asthma in exposed workers. TDI-induced asthma is associated with airway epithelium injury and repair, and subepithelial fibrosis. We investigated the effect of TDI and its hydrolysis products, the 2,4- and 2,6-toluenediamines (TDA), on viability and growth of human lung fibroblasts (HLFs) in culture, using a tetrazolium-based cell viability assay.

Determination of total mercury in estuary, lake and river sediments.

In order to improve the quality of the results in sediment analysis, the Community Bureau of Reference (BCR) of the European Communities has developed 3 sediment reference materials (CRM) from estuarine, lake and river origins. Certification of mercury content in these materials was achieved by 3 methods (cold vapor atomic absorption spectrometry, plasma emission spectrometry, neutron activation analysis with radiochemical separation). The values finally certified in the CRM estuarine, lake and river sediments are 1.