Specific triiodothyronine binding sites in the anterior pituitary of the rat.
Studies with L-[(125)l] triiodothyronine and L-[(125)l] thyroxine, and with equilibrium dialysis of plasma proteins indicate that rat pituitary binds L-triiodothyronine 9.8 times as strongly as it does L-thyroxine. Injection of even small doses of nonradioactive L-triiodothyronine reduces the pituitary/ plasma ratio of radioactive L-triiodothyronine, an indication of the existence of pituitary binding sites with a limited capacity for L-triiodothyronine. Limited capacity binding sites for L-thyroxine could not be demonstrated.
D000818:Animals; D001345:Autoradiography; D001665:Binding Sites; D001798:Blood Proteins / Q000378:metabolism; D007275:Injections, Intravenous; D007456:Iodine Isotopes; D007700:Kinetics; D008297:Male; D010902:Pituitary Gland / Q000378:metabolism*; D011485:Protein Binding; D051381:Rats; D013974:Thyroxine / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism; D014284:Triiodothyronine / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism*
D001798:Blood Proteins; D007456:Iodine Isotopes; D014284:Triiodothyronine; D013974:Thyroxine