Cytokine Production by the Spleen Under Surgical Stress

In order to examine cytokine production by the spleen under surgical stress in humans, we investigated changes of plasma cytokine levels in the arterial blood and the splenic vein blood in eight patients who underwent subtotal gastrectomy. Arterial blood was sampled 5 times: before induction, 1 and 2 hours after skin incision, and 1 and 5 days after the operation. IL-1, IL-6, endothelin, and nitrate were measured each time. Splenic vein blood was sampled twice: 1 and 2 hours after skin incision. IL-1 was not detected in any samples. Arterial IL-6 levels increased at 2 hours and returned to control levels in 5 days. Levels of IL-6 in splenic vein blood were significantly higher than in arterial blood. Arterial endothelin levels increased at 2 hours and returned to control levels in 1 day. There was no significant difference between levels of endothelin in splenic and arterial blood. No change was detected in nitrate after skin incisions and no significant difference between levels of nitrate in splenic and arterial blood was seen. These data suggest that the spleen produces IL-6 intensively under surgical stress.