Interaction of hydroxychlorobiphenyls--polychlorinated biphenyl metabolites--with the human erythrocyte membrane.

Effects of hydroxychlorobiphenyls (polychlorinated biphenyl metabolites) and chlorobiphenyls on membranes have been studied with the human erythrocyte membrane as a model. Many of the hydroxychlorobiphenyls are very effective hemolytic agents, whereas the parent chlorobiphenyls are generally quite ineffective at inducing hemolysis. The hemolytic potency of the hydroxychlorobiphenyls varies with the degree of chlorination and, more importantly, with the position of the chloro- and hydroxy- substituents. At lower concentrations, the hydroxychlorobiphenyls protect the erythrocyte against hypotonic hemolysis, while they induce hemolysis at higher concentrations. In the range of concentrations of each hydroxychlorobiphenyl required for maximum protection, the erythrocytes exist in altered morphological forms as opposed to normal discocytes. The chlorobiphenyls at lower concentrations also protect the erythrocytes from hypotonic hemolysis, but they do not induce hemolysis at higher concentrations. These studies suggest that products of the metabolism of chlorobiphenyls may be more biologically active than the parent compounds themselves. Effects on membranes may thus play a role in the mammalian toxicity of the hydroxychloro- and chlorobiphenyls.