Effect of dexmedetomidine on plasma brain-derived neurotrophic factor: A double-blind, randomized and placebo-controlled study

BACKGROUND. Dexmedetomidine (DEX) has neuro-protective effects, but the clinical mechanism remains unclear. METHOD. Forty patients were randomly divided into two groups: group A (control) and group B (treated with DEX). Plasma concentrations of brain-derived neurotrophic factor (BDNF) were determined in blood samples using enzyme-linked immunosorbent assays at five time points: T1 (baseline), T2 (15 minutes after intubation and before the surgery was started), T3 (the end of surgery), T4 (10 minutes after extubation in the post-anesthesia care unit), and T5 (24 hours after the surgery). Changes in bispect (BIS) index, heart rates, and doses of anesthetics used for induction were also recorded. RESULTS. Baseline plasma concentrations of BDNF did not differ between group A and group B; 15 minutes after induction, concentrations of plasma BDNF were significantly reduced in group A. Twenty-four hours after surgery, the concentration was still higher in group B than in group A. In contrast, plasma concentrations of BDNF at other time points tested did not differ between the two groups. CONCLUSION. It appears that DEX could reverse the reduced plasma concentrations of BDNF caused by anesthetics, and this effect lasted for 24 hours after surgery.