Metabolic response ofLumbriculus variegatusto respiratory uncoupler in cold and anoxic water

Abstract

AbstractA direct calorimetry approach was applied to compare physiological interaction of pentachlorophenol (PCP) with the energy metabolism under anoxia and normoxia in the aquatic oligochaete wormLumbriculus variegatus.In normoxia, heat dissipation begins to accelerate 10 h after the onset of PCP exposure until it settles at a new plateau level, and shows a twofold increase from the nonimpact rate. In anoxia, heat output was suppressed down to a level of ∼18% (7°C) of normoxia. An anoxic PCP exposure did not produce any notable changes in the heat output, and the amount of chemical accumulated in tissues was only a fraction (18%) of that accumulated in normoxia. Whether the inhibition of the physiological response during anoxia was due to a shift to anaerobic metabolism or to reduced accumulation in tissues, or combination of both factors, was unclear.