Effects of Low Dose Dioxin on Membrane Bound Ion Dependent ATPases in Mice Kidney

Abstract

The present communication reports the dose and exposure dependent effects of a dioxin on few ion dependent membrane bound ATPases of mice kidney. Effects of TCDD on the specific activity of few membrane bound ATPases viz., Total ATPase, Na + K + ATPase, Ca ++ ATPase, Mg ++ ATPase, Ca ++ , HCO3 - ATPase, Mg ++ , HCO3 - ATPase were observed. Two basic hypotheses were tested viz., (a) the sublethal in vivo exposure of TCDD evokes a dose and duration dependent effects on the membrane bound ATPases of the renal cells of mice and (b) TCDD possibly has a direct effect on the membrane bound ATPase system. Two groups were exposed to two sublethal doses (0.004 mg/kg bw/d, 0.04 mg/kg bw/d) of TCDD by a daily oral administration for 2, 4 and 6 days. A separate control group received corn oil for same exposure duration. The results indicated predominant exposure duration dependent alterations in membrane bound ATPases. In conclusion, the results suggested that the membrane bound ATPases were indeed influenced by the TCDD exposure. However, the effects were possibly indirect, by complex chains of reactions exhibited by the cells when subjected to the toxic stress. Keywords: ATPases, Dose & Duration dependent toxicity, Kidney, mice, TCDD