The effect of oral iodide on serum butanol-insoluble protein-bound iodine in various species.

It is possible that there is an association between the butanol-insoluble protein-bound iodine developed in plasma when potassium iodide is fed and the reduction of serum and hepatic cholesterol. This fraction constitutes most of the protein-bound iodine increase observed in iodide-fed rabbits, dogs, rats and hypertensive human beings. It appears a few days after iodide feeding is begun and disappears four to eight weeks after discontinuing iodide. The dose required to produce minimum and maximum concentrations has been determined in all of these animals and in men. Further, it was found that hypothyroidism reduced the iodide requirement to one-tenth that necessary to produce comparable amounts of butanol-insoluble protein-bound iodine in normal animals.