Cardiopulmonary Bypass (CPB) is thought to generate
reactive oxygen species associated with a systemic
inflammation and
neurotrophins seem to be involved in cardiovascular inflammatory reactions. The aim of this study was to determine the impact of CPB on plasma
neurotrophins levels and to appreciate the links existing between
inflammation, oxidative stress and
neurotrophins. Blood samples were taken from 27 patients undergoing cardiac surgery: before CPB, during
ischemia and at reperfusion under CPB. Oxidative stress was evaluated using an Electron Spin Resonance technique by
superoxide detection, and
antioxidant defences by measurement of Endogenous
Peroxidase Activity (EPA). The evolution of two
neurotrophins:
Brain Derived Neurotrophic Factor (
BDNF) and
Nerve Growth Factor (
NGF) was assessed with an ELISA method. An inflammatory index was determined by a multiplex flow cytometry method. The inflammatory index showed that MCP-1,
P-selectin, t-PA and
interleukins 6, 8 and 10 levels increased during CPB (p<0.05).
Superoxide production and EPA were higher during
ischemia and reperfusion than before CPB (p<0.05).
BDNF plasma levels were higher at reperfusion (p<0.05).
NGF levels did not change. Our study shows an increase of
BDNF levels, associated with an inflammatory phenomenon and a redox modification, in the plasma of patients undergoing cardiac surgery under CPB. The role played by this
neurotrophin in this complex situation still needs to be elucidated, in particular its cellular origin. It is also necessary to understand whether
BDNF has a beneficial or deleterious effect during CPB.