An increase of liver uptake of thyroxine, an initial step of an increased fecal loss of thyroxine in response to propylthiouracil in rats.
Propylthiouracil augmented fecal loss of thyroxine (T4), but methimazole was without effect in this respect in rats. In vitro uptake of labeled T4 by the liver was significantly enhanced by a small amount of propylthiouracil in the presence of dilute rat plasma. Methimazole was without effect under comparable conditions. In contrast, propylthiouracil and methimazole failed to affect in vitro uptake of labeled T4 by the kidney and diaphragm in the presence of dilute rat plasma. Since deiodination of T4 does not occur in the presence of dilute rat plasma, it is suggested that propylthiouracil specifically stimulates liver uptake of T4 as an initial step of an increase of biliary-fecal excretion of T4 in rats.
D000818:Animals; D005243:Feces / Q000032:analysis; D066298:In Vitro Techniques; D007455:Iodine / Q000378:metabolism; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism*; D008297:Male; D008713:Methimazole / Q000494:pharmacology; D009132:Muscles / Q000378:metabolism; D011441:Propylthiouracil / Q000494:pharmacology*; D051381:Rats; D013974:Thyroxine / Q000378:metabolism*; D013997:Time Factors
D008713:Methimazole; D011441:Propylthiouracil; D007455:Iodine; D013974:Thyroxine