Department of Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
Pediatr Crit Care Med. 2011 Mar;12(2):e79-86. doi: 10.1097/PCC.0b013e3181e89e91.
To compare the effects of pH-stat and α-stat management before deep hypothermic circulatory arrest followed by a period of low-flow (two rates) cardiopulmonary bypass on cortical oxygenation and selected regulatory proteins: Bax, Bcl-2, Caspase-3, and phospho-Akt.
Piglets were placed on cardiopulmonary bypass, cooled with pH-stat or α-stat management to 18 °C over 30 mins, subjected to 30-min deep hypothermic circulatory arrest and 1-hr low flow at 20 mL/kg/min (LF-20) or 50 mL/kg/min (LF-50), rewarmed to 37 °C, separated from cardiopulmonary bypass, and recovered for 6 hrs.
Newborn piglets, 2-5 days old, assigned randomly to experimental groups.
None.
Cortical oxygen was measured by oxygen-dependent quenching of phosphorescence; proteins were measured by Western blots. The means from six experiments ± sem are presented as % of α-stat. Significance was determined by Student's t test. For LF-20, cortical oxygenation was similar for α-stat and pH-stat, whereas for LF-50, it was significantly better using pH-stat. For LF-20, the measured proteins were not different except for Bax in the cortex (214 ± 24%, p = .006) and hippocampus (118 ± 6%, p = .024) and Caspase 3 in striatum (126% ± 7%, p = .019). For LF-50, in pH-stat group: In cortex, Bax and Caspase-3 were lower (72 ± 8%, p = .001 and 72 ± 10%, p = .004, respectively) and pAkt was higher (138 ± 12%, p = .049). In hippocampus, Bcl-2 and Bax were not different but pAkt was higher (212 ± 37%, p = .005) and Caspase 3 was lower (84 ± 4%, p = .018). In striatum, Bax and pAkt did not differ, but Bcl-2 increased (146 ± 11%, p = .001) and Caspase-3 decreased (81 ± 11%, p = .042).
In this deep hypothermic circulatory arrest-LF model, when flow was 20 mL/kg/min, there was little difference between α-stat and pH-stat management. However, for LF-50, pH-stat management resulted in better cortical oxygenation during recovery and Bax, Bcl-2, pAk, and Caspase-3 changes were consistent with lesser activation of proapoptotic signaling with pH-stat than with α-stat.
比较深低温停循环前 pH -stat 和 α-stat 管理与低流量（两种流速）心肺转流后皮质氧合和选定的调节蛋白的影响：Bax、Bcl-2、Caspase-3 和磷酸化 Akt。
小猪置于心肺转流上，用 pH-stat 或 α-stat 管理冷却至 18°C 30 分钟，深低温停循环 30 分钟，低流量 20 毫升/公斤/分钟（LF-20）或 50 毫升/公斤/分钟（LF-50）1 小时，复温至 37°C，与心肺转流分离并恢复 6 小时。
新生小猪，2-5 天大，随机分配到实验组。
无。
皮质氧通过磷光的氧依赖性猝灭来测量；蛋白质通过 Western blot 测量。结果以六次实验的平均值±sem 表示为 α-stat 的%。通过学生 t 检验确定显著性。对于 LF-20，α-stat 和 pH-stat 的皮质氧合相似，而对于 LF-50，使用 pH-stat 则明显更好。对于 LF-20，除皮质（214±24%，p=0.006）和海马（118±6%，p=0.024）中的 Bax 和纹状体中的 Caspase 3 外，其他测量的蛋白质没有差异（126%±7%，p=0.019）。对于 LF-50，在 pH-stat 组中：皮质中，Bax 和 Caspase-3 降低（72±8%，p=0.001 和 72±10%，p=0.004），pAkt 升高（138±12%，p=0.049）。海马中，Bcl-2 和 Bax 没有差异，但 pAkt 升高（212±37%，p=0.005），Caspase 3 降低（84±4%，p=0.018）。纹状体中，Bax 和 pAkt 没有差异，但 Bcl-2 增加（146±11%，p=0.001），Caspase 3 减少（81±11%，p=0.042）。
在这种深低温停循环-LF 模型中，当流量为 20 毫升/公斤/分钟时，α-stat 和 pH-stat 管理之间几乎没有差异。然而，对于 LF-50，pH-stat 管理在恢复期间导致皮质氧合更好，Bax、Bcl-2、pAk 和 Caspase-3 的变化与 pH-stat 比 α-stat 更能减少促凋亡信号的激活一致。
