2015•Zhonghua mazuixue zazhiRequires access
Role of mitochondrial apoptotic pathway in intrathecal doxepin-induced apoptosis in rat neurons
Kechang Huang, Dandan Ma, Zheng Sun, Lina Sun, Zhifei Xu
Open publisher page 0 citations
Abstract
Objective
To investigate the role of mitochondrial apoptotic pathway in intrathecal doxepin-induced apoptosis in rat neurons.
Methods
Twenty-four adult male Wistar rats, weighing 250-300 g, in which intrathecal catheters were successfully implanted without complications, were randomly divided into 4 groups(n=6 each)using a random number table: control group(group C)and different concentrations of doxepin groups(D5, D10 and D20 groups). In D5, D10 and D20 groups, 5, 10, and 20 mmol/L doxepin 0.2 μl/g were injected intrathecally, respectively.In group C, the equal volume of normal saline was given instead.At 6 h after intrathecal administration, the animals were sacrificed, and the lumbar segments of the spinal cords were obtained for detection of the cell apoptosis(by TUNEL assay), expression of Bax and Bcl-2(by immunohistochemistry), release of cytochrome c(Cyt c), and expression of caspase-3, caspase-8 and caspase-9 mRNA(using real-time reverse transcriptase polymerase chain reaction). Apoptosis rate and Bcl-2/Bax ratio were calculated.
Results
Compared with group C, the expression of Bax was significantly up-regulated, the expression of Bcl-2 was down-regulated, Bcl-2/Bax ratio was decreased, the release of Cyt c and apoptosis rate were increased, and the expression of caspase-3 and caspase-9 mRNA was up-regulated in D10 and D20 groups, the expression of Bcl-2 was down-regulated in group D20(P 0.05). The expression of Bax was significantly up-regulated, Bcl-2/Bax ratio was decreased, the release of Cyt c and apoptosis rate were increased, and the expression of caspase-3 and caspase-9 mRNA was up-regulated in D10 and D20 groups, and the expression of Bcl-2 was down-regulated in group D20 as compared with group D5(P 0.05).
Conclusion
Mitochondrial apoptotic pathways, but not death receptor pathway, is involved in intrathecal doxepin-induced apoptosis in rat neurons.
Key words:
Doxepin; Injection, spinal; Spinal cord; Apoptosis; Mitochondria