Differential regional hemodynamic effects of corticotropin in conscious sheep

Abstract

The regional hemodynamic effects of 5 days of intravenous infusion of corticotropin (ACTH) (5 μg/kg per day) were examined in conscious sheep (n=8). Mean arterial pressure increased from 81±2 to 93±3 mm Hg (P<.001) on day 2 of ACTH and remained at this level during the infusion. Cardiac output increased from 5.13±0.19 to 0.06±0.33 L/min (P<.01) because of an increase in stroke volume from 65±4 to 79±8 mL per beat (P<.01); heart rate remained unchanged. ACTH did not alter total peripheral conductance but had differential effects on regional conductances. Mesenteric conductance fell from 5.8±0.2 to a minimum of 4.9±0.3 (mL/min)/mm Hg (P<.05), and renal conductance increased from 3.5±0.3 to 4.6..