The effect of bis(p-chlorophenyl) acetic acid on the renal function of the rat.

Abstract

The principle water-soluble metabolite of DDT in mammals has been shown to be DDA (bis(p-chlorophenyl)acetic acid). Previous studies suggested that DDA was secreted by the renal proximal tubule and was reabsorbed at an unspecified site in the nephron. Since DDA has been known to produce alterations in cellular functions, the present study examined the possibility that the renal transport of DDA was capable of causing acute nephrotoxicity. When 100 mg/kg of DDA was infused iv into the rat during a 90 min period, there was a significant decrease (congruent to 20%) in the glomerular filtration rate (GFR) after 110 min from the start of administration. During these experiments, there was no change in the mean arterial blood pressure (MABP), urine flow rate (V), renal clearance of tetraethylammonium (CTEA) or fractional reabsorption of Na (FRNa). After 200 mg/kg of DDA was infused iv into the rat during a 90 min period, there was a 60% decrease in the GFR, CTEA and V. However, the decrease in renal function was accompanied by a dramatic reduction in MABP (125 to 60 mmHg). To determine whether DDA could have produced acute renal failure when the perfusion pressure was kept constant, isolated kidney experiments were performed. In these experiments, DDA (1.0 mM) was present in a dextran perfusate and the perfusion pressure was kept constant at 90 mmHg. During these experiments, the GFR, V and FRNa were decreased significantly. The results indicated that a high perfusate concentration of DDA caused acute renal failure in the isolated kidney which was produced even when the perfusion pressure was kept constant. In conclusion, DDA produced renal failure in vivo which was associated with a reduction in renal perfusion pressure; however, perfused kidney experiments indicated that DDA could have caused a direct effect on nephron function.