[Study of corticotropic function: respective values of short tests using metropirone and exogenous ACTH regardless of...

Basal plasma cortisol levels and adrenal responses to stimulation by endogenous and exogenous ACTH were compared between a group of controls and a group of patients with corticotrophic insufficiency. In addition, the adrenal response to the administration of exogenous ACTH was compared in each of these groups in relation to the timing of the test. There was a clear parallel between respective adrenal responses to exogenous ACTH and endogenous ACTH. Adrenal stimulation by exogenous ACTH may be used to investigate the residual secretion of endogenous ACTH and in the diagnosis or corticotrophic insufficiency, when a lesion interrupting functional hypothalamo-pituitary connections has been excluded. In the opposing case, use of a short test with metopirone is essential in order to confirm corticotrophic insufficiency. This test is better tolerated than the classical test and is not subject to sources of error due to urine collections.