Increased PA-Inhibitor Levels in the Postoperative Period – No Cause-Effect Relation with Increased Cortisol

Abstract

It has been reported that the level of PA-inhibitor increases in postoperative patients and on the other hand that glucocorticoids increase the PA-inhibitor level in cell culture. Because surgery is associated with increased plasma cortisol level, a relation between the postoperative increase in plasma cortisol and PA-inhibitor levels was looked for. Blood samples were collected from 8 patients undergoing extensive abdominal surgery, before operation and postoperatively at 2 hr, 4 hr, 24 hr and daily for 7 days. Plasma cortisol and PA-inhibitor were increased 2 hr after surgery, when there was a significant correlation (p less than 0.05). The maximum increase was at 24 hr and the values fell to normal on day 6. An increase in t-PA related antigen (t-PA R:Ag) and a decrease in euglobulin fibrinolytic activity (EFA) also occurred. In 7 controls 0.25 mg ACTH was given intravenously and blood was collected after 1/2, 1, 2, 4, 6 hr. Although the increase in plasma cortisol level following ACTH was comparable to that observed after surgery the increase was not associated with significant change in PA-inhibitor level, t-PA R:Ag or EFA. A cause-effect relationship between the increased plasma cortisol and PA-inhibitor level could not be shown. The mechanism of the postoperative increase in PA-inhibitor thus remains unknown.