Effects of pH and Temperature on the Uptake of Oxolinic Acid by Goldfish

Abstract

Effects of pH and temperature of the bath water on the uptake of oxolinic acid by goldfish Carassius auratus were examined.
The one-compartment model having two pharmacokinetic parameters, the volume of dis-tribution and clearance constant, was used to analyze the data. The model fitted the accumulation data except for a few places. The equilibrium concentration in goldfish at pH 6.0, 6.9 and 7.7 were 74.7, 23.4 and 11.5μg/g, respectively. Thus, the degree of accumulation was greater at pH below the pKa (=6.9) of oxolinic acid. The clearance constant was in the range of 0.39-0.56ml/h/g, and the volume of distribution was in the range of 1.65-2.19 ml/g at various water tem-neratures under the constant pH of 6.9, and both values increased with water temperature.