Glycolytic function in goldfish hepatocytes at various temperatures: effects on Na+-pump and protein synthesis

KRUMSCHNABEL G, MALLE S, SCHWARZBAUM PJ, WIESER W

JOURNAL OF EXPERIMENTAL BIOLOGY

COMPANY OF BIOLOGISTS LTD

Año: 1994 p. 285 - 290

0022-0949

Cellular metabolism of ectotherms may respond to temperature changes with a shift inthe choice of substrate preferentially catabolized for ATP production (Johnston andDunn, 1987). This has been shown in acclimated fish, in which a temperature-dependentswitch from carbohydrates as the main fuel for energy metabolism to other fuels, or viceversa, can occur. Such shifts help to indicate the relative importance of aerobic glycolysisas an ATP-supplying process. The preferred energy source at a given temperaturedepends upon the temperature range investigated, as well as on the species, on the tissueand upon nutritional factors. The adaptive significance of shifts between energy sources isnot always clear. While in some cases ecological arguments may provide plausibleexplanations (e.g. seasonal adaptation to migration and reproductive requirements; Stoneand Sidell, 1981; Moerland and Sidell, 1981), evidence is accumulating that structural orfunctional features inherent in the metabolic organisation of the cell may also play a rolein determining the nature of such responses (Sidell, 1983; Sidell and Hazel, 1987). Ofparticular relevance in this respect is the interaction between diffusional flux and the rateof enzymatic activity in shaping specific temperature effects on cellular metabolism.