Tissue distribution of the receptor for 2,3,7,8-tetrachlorodibenzo-p-dioxin in the rat.

sive animals (21 , 24). With the help of isoelectnic focusing in polyacrylamide gel, a single binding species for TCDD could be demonstrated in liver cytosol (3). Scatchard plots for the binding of TCDD measured by using this method gave a Kd of 0.6 [email protected] of TCDD to the peak focusing at p15.2 was competed for by 3-methylcholanthrene, ,8-naphthoflavone, and TCDBF, all inducers of AHH, but not by phenobarbital or pregnenobone-16a-carbonitrile, inducens of other forms of cy tochrome P-450. TCDD has been shown to induce AHH in lung, prostate, and testis (9, 10). Treatment with TCDD results in thymus involution (5, 12) and an immunodepression (5). Morphological changes have been seen in the kidney following treatment with TCDD (6). Thus, TCDD has a widespread effect in various tissues, and therefore the distribution of the TCDD receptor has been studied by quantitation by isoelectric focusing in polyacryl amide gel.