Peripheral Metabolism of Thyroid Hormones in Guinea Pigs Immunized Against Bovine Thyroglobulin. ∗

Abstract

Summary

The time required for the disappearance from the blood of one-half the radioactivity (ty_1/2) of thyroxine (T₄ ¹³¹) and triiodothyronine (T₃ ¹³¹) has been studied in normal, adjuvant treated and thyroglobulin-adjuvant immunized guinea pigs. The antibody titer in immunized animals has been estimated by the tanned red cell hemagglutination technic. The titer at 8-9 weeks was greater than at 4-5 weeks after immunization. The t_1/2 of T₄ ¹³¹ and of T₃ ¹³¹ of experimental animals was not significantly different from that of untreated and adjuvant treated controls at 5 weeks after immunization. However, at 12 weeks after immunization the t_1/2 of both radioactive hormones was markedly increased; the increase was by 201% in the case of T₄ ¹³¹ and by 86.4% in the case of T₃ ¹³¹. There was a gross inverse relationship between the t_1/2 of these radioactive hormones and the magnitude of the antibody titer. The implications of this inverse relationship have been briefly discussed.