Xenon has no effect on cytokine balance and adhesion molecule expression within an isolated cardiopulmonary bypass...

Although almost inert chemically, xenon is not unreactive biologically. It interacts with receptors involved in the expression of cytokines and adhesion molecules. The effect of xenon on the immune function in whole blood has not been studied.

We examined the effects of 70% xenon in oxygen on cytokine balance and expression of adhesion molecules in an isolated cardiopulmonary bypass (CPB) system, which simulates an evolving inflammatory response. Whole blood from 10 healthy male volunteers was circulated in a CBP system supplied with either 70% xenon in oxygen, or oxygen-enriched air - FO(2)=0.3 (control). We took samples of blood after 30, 60 and 90 min of simulated CBP. We measured interleukin (IL)-1beta, tumour necrosis factor (TNF)alpha, IL-8, IL-10, IL-1ra and TNF-sr-2 levels, and the expression of HLA-DR and the adhesion molecules L-selectin, CD18 and CD11b on monocytes, granulocytes and lymphocytes.

IL-8 concentrations were increased significantly, TNF-sr-2 concentrations decreased significantly and IL-10 levels decreased during bypass. There were no significant differences between the groups for any measured variable.

In an isolated CPB system, xenon and oxygen-enriched air had similar effects on cytokine production and expression of adhesion molecules.