Increased Metabolic Clearance of Cortisol by Stress-Susceptible Swine

The metabolic clearance rate (MCR) and turnover rate of cortisol was estimated in each of three normal and three stress-susceptible swine. Tritium-labeled cortisol was infused continuously until the level of labeled cortisol in plasma was stable. Labeled cortisol was removed from the blood of stress-susceptible pigs at approximately five times the rate of normal pigs (P<.001). Similarly, the turnover rate of cortisol was significantly elevated in stress-susceptible swine (P<.001). The results indicate that stress-susceptible swine have an increased rate of cortisol utilization and production instead of an adrenal insufficiency as has been suggested in the past.