Abstract

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is known to have profound ultrastructural and biochemical effects on hepatic and renal tissues. However, there is little information concerning the effect of TCDD on renal function. Therefore, the steady-state secretion rate of phenolsulfonphthalein (PSP) was measured in vivo in control rats and in rats pretreated with TCDD. Five to 7 days after a single intraperitoneal injection of TCDD (10 microgram/kg) there was: 1) an increase in the apparent affinity of the secretory system for PSP since a significant increase in the tubular secretion rate of PSP occurred at low plasma levels of PSP; 2) no increase in the maximum secretory capacity for PSP (Tm-PSP); 3) a significant decrease in the glomerular filtration rate; from 1.17 +/- 0.10 to 0.90 +/- 0.06 (mean +/- S.E.) ml-min-1 . g-1 wet kidney wt. The decrease in glomerular filtration in the rats treated with TCDD occurred without a change in the mean arterial pressure; this suggests that the glomerular structures may have a high sensitivity to this agent. The effect of TCDD on the tubular secretion of PSP is discussed in relation to the available information concerning the inducing effect of TCDD on renal tissue ligandin content.