Soavi Cecilia, Marušič Uroš, Sanz Juana Maria, Morieri Mario Luca, Dalla Nora Edoardo, Šimunič Bostjan, Pišot Rado, Zuliani Giovanni, Passaro Angelina
Medical Science Department, University of Ferrara, Ferrara, Italy; and.
Science and Research Centre, University of Primorska, Capodistria, Slovenia.
J Appl Physiol (1985). 2016 May 15;120(10):1118-23. doi: 10.1152/japplphysiol.01111.2015. Epub 2016 Mar 3.
Brain-derived neurotrophic factor (BDNF) is a member of the family of neurotrophins and has been implicated in brain resistance to insults. Murine studies have demonstrated increased hippocampal concentration after acute immobilization and decreased concentration after chronic immobilization. In humans, chronic stress and sedentary lifestyle result in decreased plasma BDNF levels, but there no data exist regarding acute immobilization. The aim of our study was to evaluate age-related responses [comparing 7 younger subjects (age 23 ± 3 yr) and 8 older subjects (age 60 ± 4 yr)] of plasma BDNF before (baseline data collection, BDC) and after 14 days (BR14) of horizontal bed rest (BR). At BDC, BDNF levels were not different between the two groups (P = 0.101), although at BR14, BDNF levels were higher in older subjects (62.02 ± 18.31) than in younger subjects (34.36 ± 15.24 pg/ml) (P = 0.002). A general linear model for repeated measures showed a significant effect of BR on BDNF (P = 0.002). The BDC BDNF levels correlated with fat-free mass in both populations (ALL) (R = 0.628, P = 0.012), (older, R = 0.753, P = 0.031; younger, R = 0.772, P = 0.042), and with total cholesterol in ALL (R = 0.647, P = 0.009) and older study subjects (R = 0.805, P = 0.016). At BR14, BDNF correlated with total cholesterol (R = 0.579, P = 0.024) and age (R = 0.647, P = 0.009) in ALL. With an increase in age, the brain could become naturally less resistant to acute stressors, including the detrimental effects of prolonged bed rest, and thus the increase in BDNF in the older study group might reflect a protective overshooting of the brain to counteract the negative effects in such conditions.
脑源性神经营养因子（BDNF）是神经营养因子家族的成员之一，与大脑对损伤的抵抗力有关。小鼠研究表明，急性固定后海马浓度增加，慢性固定后浓度降低。在人类中，慢性应激和久坐的生活方式会导致血浆BDNF水平降低，但尚无关于急性固定的数据。我们研究的目的是评估水平卧床休息（BR）14天之前（基线数据收集，BDC）和之后（BR14）血浆BDNF的年龄相关反应[比较7名年轻受试者（23±3岁）和8名老年受试者（60±4岁）]。在BDC时，两组之间的BDNF水平无差异（P = 0.101），尽管在BR14时，老年受试者（62.02±18.31）的BDNF水平高于年轻受试者（34.36±15.24 pg/ml）（P = 0.002）。重复测量的一般线性模型显示BR对BDNF有显著影响（P = 0.002）。在所有人群中，BDC时的BDNF水平与去脂体重相关（ALL）（R = 0.628，P = 0.012），（老年组，R = 0.753，P = 0.031；年轻组，R = 0.772，P = 0.042），并且与所有人群（R = 0.647，P = 0.009）和老年研究对象（R = 0.805，P = 0.016）的总胆固醇相关。在BR14时，BDNF与所有人群的总胆固醇（R = 0.579，P = 0.024）和年龄（R = 0.647，P = 0.009）相关。随着年龄的增长，大脑可能自然地对急性应激源（包括长期卧床休息的有害影响）的抵抗力降低，因此老年研究组中BDNF的增加可能反映了大脑的一种保护性过度反应，以抵消此类情况下的负面影响。
