Department of Neurology, The Fourth Affiliated Hospital of Harbin Medical University, 37 Yiyuan Street, Harbin 150001, P,R, China.
BMC Neurol. 2013 Dec 5;13:192. doi: 10.1186/1471-2377-13-192.
Acid-base imbalance in various metabolic disturbances leads to human brain dysfunction. Compared with acidosis, the patients suffered from alkalosis demonstrate more severe neurological signs that are difficultly corrected. We hypothesize a causative process that the nerve cells in the brain are more vulnerable to alkalosis than acidosis.
The vulnerability of GABAergic neurons to alkalosis versus acidosis was compared by analyzing their functional changes in response to the extracellular high pH and low pH. The neuronal and synaptic functions were recorded by whole-cell recordings in the cortical slices.
The elevation or attenuation of extracellular pH impaired these GABAergic neurons in terms of their capability to produce spikes, their responsiveness to excitatory synaptic inputs and their outputs via inhibitory synapses. Importantly, the dysfunction of these active properties appeared severer in alkalosis than acidosis.
The severer impairment of cortical GABAergic neurons in alkalosis patients leads to more critical neural excitotoxicity, so that alkalosis-induced brain dysfunction is difficultly corrected, compared to acidosis. The vulnerability of cortical GABAergic neurons to high pH is likely a basis of severe clinical outcomes in alkalosis versus acidosis.
各种代谢紊乱导致的酸碱失衡会引起人脑功能障碍。与酸中毒相比，碱中毒患者表现出更严重的神经体征，且难以纠正。我们假设存在这样一个因果过程，即脑细胞对碱中毒比酸中毒更为敏感。
通过分析细胞外高 pH 值和低 pH 值对 GABA 能神经元功能变化的影响，比较了它们对碱中毒和酸中毒的敏感性。在皮质切片中通过全细胞膜片钳记录神经元和突触功能。
细胞外 pH 值的升高或降低都会损害这些 GABA 能神经元产生尖峰的能力、对兴奋性突触输入的反应能力以及通过抑制性突触的输出能力。重要的是，与酸中毒相比，这些活性特性的功能障碍在碱中毒中更为严重。
与酸中毒相比，碱中毒患者大脑皮质 GABA 能神经元的严重损伤导致更严重的神经兴奋毒性，因此碱中毒引起的脑功能障碍更难纠正。皮质 GABA 能神经元对高 pH 值的敏感性可能是碱中毒与酸中毒相比临床结局严重的基础。
