Nineteen patients with Itsenko-Cushing's disease aged 13 to 18 were examined during an active stage of the disease and during a remission after proton exposure of the hypophysis. Nine normal subjects were controls. Adenohypophyseal tropic hormones and hydrocortisone were radioimmunoassayed before and after administration of nakom, a dopaminergic agent. ACTH, hydrocortisone, TTH, parlodel secretion were found decreased and LH increased in patients with Itsenko-Cushing's disease, and no STH increase characteristic of normal subjects was observed. During remission after proton therapy adenohypophyseal tropic hormones and hydrocortisone secretion normalized in response to nakom. Recovery of STH secretion was observed, but not in all patients, this being confirmed by the absence of a normal somatotropin response in nakom test in 26.32% of patients.