AJP - Renal Physiology, Vol 233, Issue 2 126-F132, Copyright © 1977 by American Physiological Society
Renal handling of the polar DDT metabolite DDA (2,2-bis[p-chlorophenyl] acetic acid) by marine fish
J. B. Pritchard, K. J. Karnaky Jr, A. M. Guarino and W. B. Kinter
The renal handling of 2,2-bis(p-chlorophenyl) acetic acid (DDA) was
examined in the isolated tubules of the winter flounder (Pseudopleuronectes
americanus) in vitro in conjunction with clearance studies in the flounder
and in the aglomerular goosefish (Lophius americanus). In vitro, both
uptake studies and autoradiography showed extensive energy-dependent
accumulation within the cytoplasm of tubular cells and the tubular lumen.
The uptake was strongly inhibited by p-aminohippurate and chlorophenol red.
A second component of uptake was insensitive to metabolic inhibitors or
organic acids and represented tissue binding. In vivo, both species showed
net secretion which was inhibited by probenecid. Comparison of DDT and DDA
distribution and excretion emphasized the importance of the greater water
solubility of DDA and of its secretory transport, since DDA was excreted at
over 200 times the rate of DDT. Liver, kidney, and bile also showed
elevated DDA tissue-to-plasma ratios. Thus, the organic acid system
mediates the accumulation and excretion of DDA in these fish.
