Observations on the relationship between the maximal thyroxine binding capacities of thyroxine-binding interalpha globulin and thyroxine-binding prealbumin, the serum protein bound iodine concentration and sexual maturity in adolescents.

Abstract

ABSTRACT The serum PBI concentration and the maximal thyroxine binding capacity for TBG and TBPA were determined in 100 adolescents. The subjects were classified according to sex and degree of sexual maturity. PBI was determined by an autoanalyzer method: Maximal thyroxine binding capacity for TBG fell with increasing maturation in males while TBPA capacity rose in both sexes. The slight changes in serum PBI noted with increasing sexual maturity correlated directly with the slight changes in TBG binding capacity; no correlation between PBI and TBPA binding capacity was observed as maturity progressed.