Stress also causes the release of ACTH and other pituitary hormones (such as growth hormone and prolactin). Chronic stress (anxiety or trauma) produces prolonged elevation of ACTH levels and thus an increase in cortisol secretion. In the investigation of patients with suspected hypopituitarism, it is clinically advantageous to be able to provoke ACTH release by producing controlled hypoglycaemia. The integrity of the hypothalamic-pituitary-adrenal axis may thus be examined by measuring the plasma concentration of cortisol (Fig. 7.11 ) and, if necessary, of other pituitary hormones that are released by stress, e.g. prolactin and growth hormone.
