Immunoreactive thyroxine levels in the serum of thyroidectomized adult newts, Notophthalmus viridescens

Abstract

The concentration of immunoreactive thyroxine was determined in blood serum samples from thyroidectomized adult newts (Notophthalmus viridescens) relative to levels found in samples of serum from intact and sham-thyroidectomized newts by means of radioimmunoassay. The results show a significant rate and degree of decline in the level of thyroxine from 24 h to 14 days post-thyroidectomy, followed by further reductions of the immunoreactive thyroxine levels between 14 and 35 days, as compared with levels in intact and sham-thyroidectomized controls.