The influence of temperature on extracellular and intracellular pH in the American eel, Anguilla Rostrata (Le Sueur).

The effects of ambient temperature (5-20 degrees C) on the pH of the extracellular and intracellular compartments of the Americal eel (Anguilla rostrata) were measured. Venous blood pH was sampled from an indwelling catheter in the caudal vein, and intracellular pH of liver, heart, white muscle, and red muscle was estimated by the distribution ratio of 14C-5,5 dimethyloxazolidine-2,4-dione (DMO). The absolute value of pH varies in a manner blood greater than liver greater than red muscle greater than heart and white muscle. The values for the change in pH with temperature (delta pH/delta T degrees C) are: blood, -0.0076; liver, -0.0177; heart, -0.0203; white muscle, -0.0090; red muscle, -0.0033. Delta pH/delta T degrees C values for blood, white muscle and red muscle are not statistically different, and are far from the -0.018 value predicted by the alphastat hypothesis. In contrast, delta pH/delta T degrees C values for liver and heart are statistically different from blood and match those expected for alphastat regulation. The results are discussed in the context of the alphastat hypothesis and metabolic 'torpor' in the American eel.