Abstract

Following the pioneering work of Roger Ekins in describing the methodology for radioimmunoassay of hormone concentrations in plasma a series of publications followed describing variation in plasma hormone concentrations in a number of diseases. Though fluctuations in hormonal concentrations had been suspected, it was not until Hunter and Rigal documented these for the GH axis that it became apparent that the preferred mode of signalling for many hormone systems and in particular the anterior-pituitary hormones was of a pulsatile nature.