Growth Hormone Secretion in Acromegaly

Abstract

Although striking clinical features of acromegaly had been noticed for a long time, their association with hypersecretion of growth hormone (GH) was first suggested by Cushing. Since then, many attempts have been made to demonstrate an increase of GH in plasma from acromegalic patients. Early studies using the tibia epiphyseal bioassay method revealed the presence of growth-promoting factors in lyophilized plasma from acro-megalic patients (1). It was difficult, however, to quantify plasma GH levels using this bioassay method. The hemoagglutination inhibition assay offered greater sensitivity but this procedure was still not satisfactory for measuring the small amounts of GH present in plasma (2). More recently the sensitive and reliable measurement of plasma GH was made possible by the introduction of a radioimmunoassay (RIA) for GH (3,4). Since then, RIAs for GH have been extensively used for studying GH secretion in patients with acromegaly. In this article, we discuss GH secretion in acromegalic patients based on results obtained from studies conducted in our laboratory as well as findings reported in the literature.