Fig. 1.

Effect of restraint stress on corticosterone and Hcy concentrations in rat plasma. a Corticosterone concentration in rat plasma was increased significantly after restraint stress. Compared to control, the peak was observed in the group of acute stress for 6 h (379.1 ± 81.3 vs. 36.2 ± 9.8 ng/ml), and higher levels were maintained during chronic stress for 3 weeks (255 ± 53.3 ng/ml for 1-week stress, 310.9 ± 59.7 ng/ml for 2-week stress and 327.7 ± 75.1 ng/ml for 3-week stress, respectively). b The plasma Hcy levels in rats exposed to stress were markedly increased. The peak concentration of Hcy occurred in the acute stress group, and increased by 3.3-fold compared with the control (8.57 ± 2.37 vs. 2.64 ± 0.91 μmol/l). In the chronic stress groups, Hcy levels gradually increased with stress time prolongation, resulting in an approximately 2.7-fold increase (7.11 ± 2.14 μmol/l) after psychological stress 3 weeks. (n = 8, **p < 0.01 compared with control)