Production of interleukin-6 at operative wound sites in surgical patients.

Abstract

Interleukin-6 (IL-6) plays a central role in the acute phase of inflammation after surgical injury. The serum concentration of IL-6 increases during an operation. The mechanisms of this increase in the serum IL-6 level, however, has not yet been fully clarified. To determine the possibility of production of IL-6 at the operative wound site and its regulation by humoral factors in surgical patients, the IL-6 secretion of biopsied skin obtained from an operative wound both before and after the operation were quantitated by using organ culture techniques. When skin explants obtained from the uninjured skin were cultivated and the amounts of IL-6 secreted into the culture medium were measured, IL-6 secretion increased exponentially during culture, which indicated that the stress of the skin incision induced IL-6 production. The skin specimens obtained from the operative wounds postoperatively secreted a significantly larger amount of IL-6 than those obtained from uninjured skin either preoperatively or postoperatively, implying that skin at the site of the operative wound had been more sensitized to produce IL-6 because of the surgical injury. The IL-6 secretion by skin explants was significantly enhanced either by tumor necrosis factor or interleukin-1, while it was inhibited by corticosteroids. Interleukin-6 production at the site of the operative wound is partly responsible for the elevation of the serum IL-6 level during the operation. Organ cultures of the skin explants may provide a feasible system for research on the cytokine networks in surgical patients.