[Measurements of serum pituitary hormones and dynamic tests to evaluate the pituitary functions]

Hormones produced by the anterior pituitary have conventionally been measured in the serum by radioimmunoassays (RIA), whereas more sensitive immunoradiometric assays (IRMA) have now been developed and are replacing RIA. Dynamic tests (stimulatory tests and suppression tests) rather than single and random determinations are often important tools in the study of pituitary functions. Stimulatory tests (such as glucagon plus propranolol test for growth hormone and water deprivation test for arginine-vasopressin) are used to evaluate hypofunction and suppression tests (such as dexamethasone suppression test for adrenocorticotrophic hormone) are used to investigate hyperfunction. This chapter, mainly dealing with representative dynamic tests, describes test protocols and how to interpret test results.