Effect of acupuncture on expression of endoplasmic reticulum Ca2+ and Caspase-12 protein in hippocampal neurons of rats with convulsive brain injury

Abstract

To observe the effect of acupuncture on endoplasmic reticulum calcium, apoptosis number and Caspase-12 protein expression in hippocampal neurons of convulsive rats, so as to explore its mechanisms underlying improvement of convulsion. SD rats were randomly divided into normal control, model and acupuncture groups, with 36 rats in each group. Rats in the normal control group received intraperitoneal injection (i.p.) of normal saline (2 mL), and those of the other 2 groups received i.p. of pentylenetetrazole (50 mg/kg) for establishing convulsion model. Manual acupuncture stimulation was applied to "Baihui"(GV20) and "Dazhui"(GV14) for 30 min after modeling. The hippocampal tissues were taken at 2, 12 and 48 h after modeling. The endoplasmic reticulum Ca2+ concentration (optical density, OD) was detected by using fluorescence probe technique and laser confocal microscopy, and the number of apoptosis of hippocampal neurons at the 3 time points detected by using terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) stain. The expression of Caspase-12 protein in hippocampus at 3 time points was observed by immunohistochemistry. In comparison with the normal group, the number of apoptotic cells of hippocampal neurons and the expression levels of Caspase-12 protein in hippocampus at 2, 12 and 48 h after seizures were obviously increased (P<0.01), and the OD value of Ca2+ at 3 time points significantly decreased (P<0.01) in the model group.Following acupuncture intervention, the increased levels of the number of apoptotic cells of hippocampal neurons and the expression of Caspase-12 protein in hippocampus at 3 time points and the decreased levels of OD value of Ca2+ at 3 time points were reversed in the acupuncture group (P<0.05, P<0.01). Acupuncture intervention is effective in reducing the apoptosis of hippocampal neurons in convulsion rats, which may be related to its functions in down-regulating Caspase-12 expression and promoting influx of Ca2+ in the hippocampal neurons.