EFFECT OF SURGICAL TRAUMA ON SPLENOCYTE AND PERITONEAL MACROPHAGE IMMUNE FUNCTION

Although previous studies have shown that simple laparotomy produces a depression in peritoneal macrophage (M phi) antigen presentation capa city, it remains unknown whether the adverse effects of laparotomy are limited to peritoneal M phi or whether such an insult also affects sp lenocyte immune function. To study this, mice were anesthetized and a 1-inch midline abdominal incision was made, followed by abdominal clos ure. At 2 and 24 hours after the surgical procedure, the animals were killed, splenocyte cultures established and stimulated for 48 hours wi th concanavalin A (2.5 mu g/mL), while peritoneal macrophage cultures were stimulated with LPS (10 mu g/mL). The proliferative capacity of t he splenocytes, as well as their ability to release interleukin-2 and interleukin-3, was markedly decreased at 2 as well as 24 hours after l aparotomy. Furthermore, the release of interleukin-6 by splenic and pe ritoneal macrophages from animals that underwent laparotomy were also significantly depressed at both 2 and 24 hours. These results support the concept that surgical stress in the form of midline laparotomy per se is sufficient to produce a significant impairment in cell-mediated immunity, thus setting the stage for increased incidence of postopera tive complications.