Associations between serum and plasma brain-derived neurotrophic factor and influence of storage time and centrifugation strategy

Abstract

The aims of the study were to clarify the impact of storage time and centrifugation strategy on brain-derived neurotrophic factor (BDNF) levels in human serum and plasma samples. In addition, we analyzed associations between BDNF levels, cardiorespiratory ftness and waist circumference. Seventeen healthy males (25.2 (4.1) years) were included in the study. Blood samples were drawn after an overnight fast and treated to diferent protocols, varying in time before centrifugation and centrifugation strategy. BDNF was analyzed in serum, normal plasma (NP) and platelet-poor plasma (PPP). Also, waist circumference and cardiorespiratory ftness were measured. A large increase was observed in serum BDNF levels during the frst hour of clotting. BDNF in NP correlated with PPP, whereas no correlations were found between BDNF in serum and plasma. Though not statistical signifcant, correlations between ftness and BDNF in serum changed from positive at 30min. to negative when clotting time was ≥60min. In conclusion, BDNF levels in serum were afected by clotting time, whereas BDNF levels in plasma were infuenced by centrifugation strategy. Importantly, BDNF in serum and plasma appears to refect two diferent pools of BDNF. The biological relevance of the velocity of BDNF release during clotting and its dependence upon ftness must be investigated further.