Effects of hypoxia on energy metabolism in goldfish hepatocytes

DORIGATTI M, KRUMSCHNABEL G, SCHWARZBAUM PJ, WIESER W

COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. PART B, BIOCHEMISTRY & MOLECULAR BIOLOGY.

ELSEVIER SCIENCE INC

Año: 1997 p. 151 - 158

1096-4959

The present study addresses the question whether long-term acclimation to hypoxia of the wholeanimal is accompanied by a chronic re-organization of cellular function and metabolism. To this end, long- andshort-term effects of hypoxia on energy metabolism were studied in hepatocytes isolated from goldfish acclimatedto normoxia or hypoxia (10% air saturation). Aerobic (oxygen consumption) and anaerobic (lactate productionunder chemical anoxia) ATP turnover was not affected by acclimation to hypoxia. The initial ATP content,a crude measure of energy status, was elevated in hypoxia-acclimated cells compared with normoxic controlsbut returned to control levels within 3 hr of normoxic exposure. Na1 pump activity and the rate of proteinsynthesis were estimated from inhibitor sensitive rates of oxygen consumption. Neither of these two major ATPconsumers of the cell was significantly altered by hypoxia acclimation, although Na1 pump activity showed atendency to be elevated in the acclimated cells. During exposure to chemical anoxia, a pronounced decreaseof lactate production was observed in hepatocytes that may have been related to metabolic acidosis. The decreaseof anaerobic energy output was not accompanied by a decrease of cellular [ATP] and is therefore believed toreflect metabolic depression. The anaerobic energy metabolism of goldfish hepatocytes relies on ample glycogenreserves and does not involve ethanol formation as a way to minimize acidotic load. comp biochem physiol117B;1:151–158, 1997. Ó 1997 Elsevier Science Inc.