Roberts E L, Chih C P
Geriatric Research, Education, and Clinical Center, Miami VA Medical Center, Florida, USA.
J Cereb Blood Flow Metab. 1997 May;17(5):560-6. doi: 10.1097/00004647-199705000-00010.
Changes in intracellular and extracellular pH may influence the vulnerability of brain tissue to anoxic or ischemic damage. In the present study, we investigated whether the increased vulnerability of aged brain tissue to anoxic damage is associated with age-related alterations in pH regulation. We obtained evidence for altered pH regulation by measuring concurrent changes in intracellular and extracellular pH before, during, and after anoxia in hippocampal slices from young adult (6-8 months old) and aged (24-27 months old) rats. We found indications of impaired pH regulation in aged hippocampal slices (a) before anoxia, as seen in a lower resting intracellular pH, (b) during anoxia, as seen in a slower decline in extracellular pH, and (c) during recovery after anoxia, as seen in a slower rate of recovery of intracellular pH. Age-related changes in pH regulation may contribute to the faster onset of anoxic depolarization in aged brain tissue during anoxia.
细胞内和细胞外pH值的变化可能会影响脑组织对缺氧或缺血损伤的易损性。在本研究中，我们调查了老年脑组织对缺氧损伤易感性增加是否与pH调节的年龄相关变化有关。通过测量年轻成年（6 - 8个月大）和老年（24 - 27个月大）大鼠海马切片在缺氧前、缺氧期间和缺氧后的细胞内和细胞外pH值的同时变化，我们获得了pH调节改变的证据。我们发现老年海马切片在（a）缺氧前pH调节受损，表现为静息细胞内pH值较低；（b）缺氧期间pH调节受损，表现为细胞外pH值下降较慢；（c）缺氧后恢复期间pH调节受损，表现为细胞内pH值恢复速率较慢。pH调节的年龄相关变化可能导致老年脑组织在缺氧期间更快地发生缺氧去极化。
