PLASMA-LEVELS OF CORTICOTROPIN-RELEASING HORMONE IN THE INFERIOR PETROSAL SINUSES OF HEALTHY-VOLUNTEERS, PATIENTS WITH CUSHINGS-SYNDROME, AND PATIENTS WITH PSEUDO-CUSHING STATES

The objective of this study was to determine whether measurements of h uman CRH in the inferior petrosal sinuses could distinguish patients w ith Cushing's syndrome from those with pseudo-Cushing states or normal physiology. Twenty-five patients with Cushing's disease, 17 patients with the syndrome of ectopic ACTH, 7 patients with Cushing's syndrome of adrenal origin, 6 patients with pseudo-Cushing states, and 11 volun teers believed to have normal hypothalamic-pituitary-adrenal axes were studied. Basal plasma human CRH and ACTH were measured at two time po ints in the petrosal sinuses and in a peripheral vein. Most subjects w ere studied after the administration of intravenous diazepam or midazo lam and fentanyl, hut because of the known inhibitory effects of such sedation on CRH secretion; 2 normal volunteers and 3 patients with pse udo-Cushing states were studied without sedation. Human CRH levels wer e near or below the detection Limit of the assay in all subjects. Alth ough the normal volunteers and patients with pseudo-Cushing states who were studied without sedation had significantly greater inferior petr osal sinus ACTH levels than those who received sedation, there were no differences in measured human CRH levels for any of the groups. We co nclude that inferior petrosal sinus human CRH levels are not easily me asured in the inferior petrosal sinuses and cannot be used to determin e whether individual patients may have hypersecretion of CRH causing t heir ACTH secretion.