2,3,7,8 TCDD, a

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.

Present communication reports in vivo dose and duration dependent effects of a dioxin (2,3,7,8 TCDD) on few membrane bound ion dependent ATPases of mice hepatocytes. Two hypotheses were tested in this study. Separate groups of mice were exposed to two very low sublethal doses (0.004 mg/kg bw, 0.04 mg/kg bw) of TCDD by daily oral administration for 2, 4 and 6 days. Separate control groups were also maintained which received only corn oil, the vehicle. The results indicated a significant exposure duration dependent alterations in the membrane ATPases. No clear dose dependent effects were observed. The results suggested that the observed alteration in the enzyme activity was possibly due to the oxidative stress generated by TCDD on the membrane-bound ion-dependent ATPases. The results also indicated that the membrane bound hydrophilic ATPases were indeed influenced by the hydrophobic TCDD. However, the effects were possibly indirect through complex chain of reactions exhibited by the cells under in vivo conditions. ROS was suspected to have played an important role in the alterations of membrane transport systems and permeability which caused cellular injury, and thereby exhibiting exposure duration dependent effects.

Polychlorinated biphenyls (PCBs) are industrial POPs which have been released into the environment resulting in widespread and persistent contamination. The aim of the present investigation was to determine the alterations in the activities of few lysosomal enzymes (acid phosphatase, α-galactosidase, βgalactosidase and β-glucuronidase) in lysosomal cellular sub-fractions of kidney and intestine of mice after the exposure to different concentrations of Aroclor 1254 (25 µg/ml, 50 µg/ml and 100 µg/ml) for two different time intervals (15 and 30 minutes). The study was aimed to answer a couple of hypothesis set in null form, that (a) Aroclor 1254 does not have any direct effect on the selected lysosomal enzymes under in vitro condition, and (b) Aroclor 1254 does not exhibit any organ-specific toxic effects on the activities of selected lysosomal enzymes in kidney and intestine of mice under in vitro condition. The overall results of the present study revealed that the even very low concentration of Aroclor 1254 has direct and organ-specific toxic effects on the activities of selected lysosomal enzymes in kidney and intestine of mice, cancelling both the hypotheses. Therefore, the results of present study were suggested that Aroclor 1254 have the ability to induce the lysosomal destabilization by altering the activities of different lysosomal enzymes which may lead to apoptosis or necrosis in different tissues of mice.

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