Work of Digital Vasoconstriction Produced by Infused Norepinephrine in Cushing's Syndrome

Measurements of sensitivity of the digital blood vessels to infused norepinephrine were made in 4 patients with Cushing's syndrome due to adrenal cortical tumor or hyperplasia and 13 patients treated with ACS or ACTH. These were compared with similar measurements made in 15 untreated normotensive subjects. Norepinephrine sensitivity was increased in Cushing's syndrome and in patients treated with ACS and ACTH despite the absence of significant hypertension in the latter group. The evidence suggests that ACTH indirectly and ACS directly may inhibit those chemical substances present in the walls of blood vessels which are responsible for inactivating norepinephrine.