Effects of propofol on the expression of B-cell lymphoma-2 assaciated protein and B-cell lymphoma-2 in the hippocampus of neonatal rats

Objective To investigate the effects of propofol on the expression of B-cell lymphoma-2 assaciated protein (Bax) and B-cell lymphoma-2(Bcl-2) in the hippocampus of neonatal rats. Methods A total of 112 male newborn Sprague Dawley (SD) rats aging 7 d were randomly divided into 8 groups (n=14): control group (Con1 group, intraperitoneally given normal saline for 5 d), and P50, P100 and P150 groups which received 50, 100 mg/kg and 150 mg/kg propofol once per day for 5 d, respectively; and control 2 group (Con2 group, intraperitoneallyl receiving normal saline for 5 d, and appendectomy was performed under propofol anesthesia for the last day) and SP50, SP100 and SP150 groups which received 50, 100 mg/kg and 150 mg/kg propofol for 5 d respectively, and appendectomy was performed under propofol anesthesia for the last day). Two months after the experiments, the level of Bcl-2 (inhibitor of apoptosis proteins) and Bax (the proapoptotic protein) were detected using immunohistochemical methods. Results Compared with the Con1 group, the levels of Bax in the P50, P100 and P150 groups increased, while the amounts of Bcl-2 gradually decreased in the P100 and P150 groups(P<0.05). Compared with the P50 group, the levels of Bax increased (P<0.05), while the amounts of Bcl-2 decreased in the P100 and P150 groups. Compared with the Con2 group, the level of Bax in the SP50, SP100 and SP150 groups gradually increased (P<0.05), while the amount of Bcl-2 in the SP50 and SP150 groups gradually decreased (P<0.05). Compared with the SP50 group, the level of Bax in the SP100 and SP150 groups increased (P<0.05), while the amounts of Bcl-2 was decreased in the SP150 group (P<0.05). Conclusions Repeated administration of propofol can inhibit the activation of Bcl-2 and enhance the expression of Bax. It can promote the apoptosis of hippocampal neurons of newborn rats in a dose-dependent manor. Key words: Propofol; Neonatal rat; Hippocampus; Apoptosis