Apoptosis in dab (Limanda limanda) as possible new biomarker for anthropogenic stress

Apoptosis, also known as programmed cell death, is a physiological and irre versible process in tissue homeostasis that leads to DNA fragmentation of m ultiples of 180-200 bp. Because apoptosis can be initiated not only by phys iological stimuli but also by various chemical substances, the present pape r investigates the suitability of apoptosis as a biomarker for biological e ffect monitoring in the marine environment. Aquarium experiments with dab ( Limanda limanda) were carried out to examine the effects of exposure to cad mium, PCB 118, and PCB 77 (each 1 mg/kg fish wt) on apoptosis in dab liver. Determination of apoptosis was carried out by DNA gel electrophoresis and quantification of DIVA fragments smaller than 1500 bp. In addition, accumul ated amounts of cadmium, PCB 118, and PCB 77 in dab liver were analyzed. Qu antification of the three xenobiotics resulted in an accumulation of about factor 10(2)-10(4). Exposure to PCB 118 and cadmium resulted in an increase in apoptotic DNA fragmentation. Exposure to PCB 77 led mainly to cell deat h by necrosis. (C) 1999 Academic Press.