The effects of 2,3,7,8-tetrachloro-dibenzo-p-dioxin on human polymorphonuclear leucocytes

Suspensions of human polymorphonuclear leucocytes were treated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) at concentrations 10(-8), 10(-7), 10(-6) and 10(-5) M. The TCDD provoked a progressive extracellular release of the lysosomal enzyme beta-N-acetylglucosaminidase and the cytoplasmic enzyme lactate dehydrogenase in a dose-dependent fashion. At all concentrations TCDD was much more effective in releasing beta-N-acetylglucosaminidase than lactate dehydrogenase. Different responses of the two enzymes to TCDD might be explained by differential structural affinities of beta-N-acetylglucosaminidase for the lysosomal membrane and of lactate dehydrogenase for the cytoplasm. It is likely that TCDD affected the solubility of beta-N-acetylglucosaminidase to a higher extent than that of lactate dehydrogenase, which is probably firmly attached to the cytoplasm.