【摘要】 目的 探讨慢性缺氧对大鼠岩神经节神经元酸敏感离子通道（acid-sensing ion channels，ASICs）亚型3（ASIC3）和亚型2a（ASIC2a）表达的影响。 方法 将12只健康成年SD大鼠随机分为正常组和缺氧组。用免疫组织化学法（PV）观察正常和慢性缺氧大鼠岩神经节神经元ASIC3和ASIC2a的表达。 结果 给予慢性缺氧刺激后，岩神经节ASIC3阳性表达神经元数目增多（Plt;0.05），灰度值降低（Plt;0.05）；而ASIC2a阳性表达神经元数目和灰度值无明显变化（Pgt;0.05）。 结论 慢性缺氧可上调大鼠岩神经节神经元ASIC3的表达，而对ASIC2a的表达无明显影响，提示ASIC3和ASIC2a可能在岩神经节对缺氧的反应中起着不同的作用。【Abstract】 Objective To investigate the effects of chronic hypoxia on expression of acid-sensing ion channels (ASIC) 3 and ASIC2a in neurons of petrosal ganglions of rats. Methods A total of 12 SD rats were randomly assigned to control group and hypoxia group. The expressions of ASIC3 and ASIC2a of the neurons in the petrosal ganglions in the two groups were investigated with the immunohistochemical technique. Results The level of positive ASIC3 expression in the petrosal ganglions was higher in the hypoxia group than that in the control group (Plt;0.05); the difference of positive ASIC2a expression levels between the control group and the hypoxia group was not statistically significant (Pgt;0.05). Conclusion Chronic hypoxia can significantly increase the expression of ASIC3, but not that of ASIC2a, of the neurons in the petrosal ganglions, suggesting their different roles in mediating a cellular response to chronic hypoxia.
Objective To study the impact of chronic hypoxia on white matter (WM) injury and brain development delay using a neonatal rat model, and to explore its value in simulating chronic hypoxic brain damage in cyanotic congenital heart disease (CHD). Methods Three-day-old Sprague-Dawley (SD) rats were randomly distributed to an experiment group (n=36, FiO2 10.5%±1.0%) and a control group (n=36, FiO2 21.0%±0.0%) and were raised for 12 days. (1) Body weight of SD rats was recorded every day and fresh brain weight was measured on P14. (2) H&E staining was performed on sections of brain tissue to observe pathological changes and ventricular size. (3) Immunohistochemistry (IHC) was applied to reveal alterations of oligodendroglial progenitor cells (OPC), preoligodendrocytes (PreOL) and myelin basic protein (MBP) in brain WM area. (4) Protein was extracted from 50 mg of brain tissue in WM area and expression of MBP was determined using Western blotting. (5) Motor function and coordination of rats (P30) were assessed via rotation experiment. Results (1) Body weight and brain weight were significantly less in the experiment group compared with the control group on P14 (body weight 14.92±1.26 gvs. 30.26±1.81 g, t=7.51, P<0.01; brain weight 0.68± 0.05 gvs.0.97±0.04 g, t=13.26, P<0.01); (2) HE staining: Sections of brain tissue from the experiment group showed ventricular size enlargement with a statistical difference (P<0.01), disordered cell organization, local neuronal death and leukomalacia. (3) The number of OPC and PreOL in the experiment group were significantly less than those in the control group (64.8±6.3vs. 126.2±8.4, t=11.19, P<0.01; 19.1±7.6vs. 46.7±9.5, t=7.28, P<0.01, respectively). MBP distribution was sparse and disorganized in the experiment group. (4) Western blotting: Expression of MBP was less in the experiment group (P<0.01). (5) Behavioral test: Time on rotarod was less in the experiment group with a statistical difference (P<0.01). Conclusion Chronic hypoxia can result in WM injury and brain development delay in neonatal rats, with features comparable to those seen in infants with cyanotic CHD.