Weiskopf R B, Gabel R A, Fencl V
J Appl Physiol. 1976 Jul;41(1):93-7. doi: 10.1152/jappl.1976.41.1.93.
In six healthy male volunteers at sea level (PB 747-759 Torr), we measured pH and PCO2 in cerebrospinal fluid (CSF), and in arterial and jugular bulb blood; from these data we estimated PCO2 (12) and pH for the intracranial portion of CSF. The measurements were repeated after 5 days in a hypobaric chamber (PB 447 Torr). Both lumbar and intracranial CSF were significantly more alkaline at simulated altitude than at sea level. Decrease in [HCO3-] IN lumbar CSF at altitude was similar to that in blood plasma. Both at sea level and at high altitude, PCO2 measured in the lumbar CSF was higher than that estimated for the intracranial CSF. At altitude, hyperoxia, in comparison with breathing room air, resulted in an increase in intracranial PCO2, and a decrease in the estimated pH in intracranial CSF. With hyperoxia at altitude, alveolar ventilation was significantly higher than during sea-level hyperoxia or normoxia, confirming that a degree of acclimatization had occurred. Changes in cerebral arteriovenous differences in CO2, measured in three subjects, suggest that cerebral blood flow may have been elevated after 5 days at altitude.
在6名海平面（气压747 - 759托）的健康男性志愿者中，我们测量了脑脊液（CSF）、动脉血和颈静脉球血中的pH值和PCO₂；根据这些数据，我们估算了CSF颅内部分的PCO₂和pH值。在低压舱（气压447托）中5天后重复进行测量。模拟海拔高度时，腰椎和颅内CSF均比海平面时明显更偏碱性。海拔高度时腰椎CSF中[HCO₃⁻]的降低与血浆中的相似。在海平面和高海拔时，腰椎CSF中测量的PCO₂均高于颅内CSF估算值。在高海拔时，与呼吸室内空气相比，高氧导致颅内PCO₂升高，颅内CSF估算pH值降低。在高海拔时进行高氧处理，肺泡通气显著高于海平面高氧或常氧时，证实已发生一定程度的适应。在3名受试者中测量的脑动静脉CO₂差值变化表明，在海拔高度5天后脑血流量可能升高了。
