Kontos H A, Raper A J, Patterson J L
Stroke. 1977 May-Jun;8(3):358-60. doi: 10.1161/01.str.8.3.358.
The mechanism by which the local effect of CO2ON pial arterioles is exerted was examined in anesthetized cats equipped with a cranial window for the direct observation of the microcirculation of the parietal cortex. The dilation of pial arterioles in response to application of artificial cerebrospinal fluid with low pH was the same whether or not the PCO2 of the solution was maintained in the normal range or markedly increased. The constriction of pial arterioles in response to application of artificial cerebrospinal fluid with high pH was the same whether or not the PCO2 of the solution was maintained in the normal range or markedly decreased. Finally, pial arterioles did not change their caliber in response to application of cerebrospinal fluid with unchanged pH but markedly increased or decreased Pco, or bicarbonate ion concentration. These results show that the action of CO2 on cerebral vessels is exerted via changes in extracellular fluid pH and that molecular CO2 and bicarbonate ions do not have independent vasoactivity on these vessels.
在配备有用于直接观察顶叶皮质微循环的颅窗的麻醉猫中，研究了二氧化碳对软脑膜小动脉产生局部作用的机制。无论溶液的PCO₂维持在正常范围内还是显著升高，用低pH值的人工脑脊液处理时软脑膜小动脉的扩张情况都是相同的。无论溶液的PCO₂维持在正常范围内还是显著降低，用高pH值的人工脑脊液处理时软脑膜小动脉的收缩情况都是相同的。最后，用pH值不变但Pco₂或碳酸氢根离子浓度显著升高或降低的脑脊液处理时，软脑膜小动脉的口径没有变化。这些结果表明，二氧化碳对脑血管的作用是通过细胞外液pH值的变化来实现的，分子态二氧化碳和碳酸氢根离子对这些血管没有独立的血管活性。
