Fig. 1.

The changes of the serum S100B level in the treated and saline groups during the different time-points (6, 24, and 48 h) after methadone overdose (15 mg/kg; i.p.). In the M/N-Apnea group, a single dose of naloxone (2 mg/kg; i.p.) was administered following methadone overdose immediately after the occurrence of apnea. In the M/N-Sedate group, a single dose of naloxone (2 mg/kg; i.p.) was administered immediately in the initiation of sedation state following methadone overdose (10 min after methadone administration). In each saline, methadone and naloxone groups, saline, methadone, or naloxone were administered alone, respectively. Data presented as mean ± SEM from 3 rats per group. * P < 0.05; *** P < 0.001 as compared with the 6 h group in the same animals. ^†P < 0.05; ^†††P < 0.001 as compared with the saline group. ^‡P < 0.05; ^‡‡P < 0.01 as compared with the methadone group