Role of metabolism in dimethylnitrosamine-induced immunosuppression: a review.

Dimethylnitrosamine (DMN) has been characterized as a potent hepatotoxin, carcinogen and mutagen. As described below, immunotoxicity should be added to its profile of activity. Although a broad spectrum of immune parameters is affected by DMN, humoral immunity is particularly sensitive. In order for DMN to produce its traditional profile of toxicity it requires metabolic activation to reactive intermediates which alkylate macromolecules. Similarly, DMN also must be metabolized to produce its immunological effects. However, as this review suggests, the metabolism of DMN to an intermediate capable of suppressing the humoral immune response may be qualitatively and/or quantitatively different from that which mediates hepatotoxicity and genotoxicity.