Plasma transferrin levels in abnormal endocrine states. I. The changes in hypophysial diseases before and after treatment.

The concentrations of plasma transferrin (Tf), which has been described possessing growth promoting activity in vitro, were determined in patients with hypophysial diseases before and after treatment. Plasma Tf levels in 74 healthy subjects were 269 +/- 3 (mean +/- SE) mg/dl. In 11 patients with active acromegaly, they were elevated to 353 +/- 11 mg/dl (P less than 0.001), while they were reduced to 168 +/- 14 mg/dl in 8 patients with hypopituitarism (P less than 0.001). They were normalized after appropriate treatment. These data indicate that plasma Tf varies according to endocrine status in relation to that of plasma somatomedin-C, and therefore its measurement may be useful clinically for the evaluation of the status of growth factors. However, the values should be assessed carefully in cases with proper Tf abnormalities, such as hematological, hepatic or renal disorders.