We studied the effects of dehydroabietic acid (DHAA), a major toxic resin acid in wood industry effluents, on cellular energetics in rainbow trout (Oncorhynchus mykiss) hepatocytes. In addition, the role of DHAA-induced change in intracellular Ca(2+) in the energetic responses of the cells was evaluated. At sublytic concentrations, DHAA caused a reduction in cellular ATP content and a concomitant enhancement of glycolytic activity of the cells in a dose-dependent manner. No further decrease of cellular ATP content occurred after 60 min of DHAA-treatment indicating establishment of new energetic steady state in cells. DHAA also caused a rapid dose-dependent increase in oxygen consumption and in cellular heat production of the hepatocytes. The effect of DHAA on ATP content and glycolytic activity was independent from Ca(2+), whereas, changes in oxygen consumption and heat production were Ca(2+)- dependent. These results show that DHAA induces energetic imbalance in rainbow trout hepatocytes, which is apparently not due to direct interference of DHAA with ATP production nor does it seem to be caused by an indirect effect of elevated intracellular Ca(2+) concentration on mitochondrial energetics. Therefore, the ATP depletion is likely due to increased cellular ATP consumption caused by amphiphilic action of DHAA on the cell membrane. (C) 2003 Elsevier Science B.V. All rights reserved.