Thyroid function and peripheral thyroxine metabolism after hemorrhage in the rat

¹ Surgical Section of the Research Institute, The Jewish Hospital of Saint Louis; and Department of Physiology, Washington University School of Medicine, Saint Louis, Missouri

Various parameters of thyroid gland function and of thyroid hormone level regulation in the serum have been investigated in the rat after acute, massive hemorrhage. There was a slight but significant depression of the protein-bound serum iodine. This depression was not associated with a release of additional TSH as inferred from the fact that thyroidal iodine release was inhibited. Other changes observed after hemorrhage were an increase in T:S iodide concentration ratio and a marked inhibition of biliary content of iodide which rapidly returned toward control values. There was no apparent change in the rate of thyroxine disappearance from the circulation after hemorrhage, but the only plausible interpretation of this observation is peripheral inhibition of thyroxine utilization.