Intracellular pH of brain: alterations in acute respiratory acidosis and alkalosis.
To evaluate the metabolic adaptations of the brain to acute respiratory acid-base disturbances, a method was developed to measure intracellular pH (pHi) in the brain of dogs under conditions in which arterial pH is rapidly altered. Brain pHi was determined by measuring the distribution of 14C-labeled dimethadione (DMO) in brain relative to cortical CSF. Brain extracellular space (ECS) was evaluated as the 35SO4 = space relative to cortical CSF, and arterial Po2 was maintained at 82-110 mmHg. In normal dogs, brain (cerebral cortex) pHi was 7.05, and after 1 h of hypercapnia (arterial pH = 7.07) it fell to 6.93. However, after 3 h with arterial Pco2 maintained at 85 mmHg brain pHi was normal (7.06), and during this time brain bicarbonate had risen from 11.3 to 24.4 meq/kg H2O. These changes were not prevented by intravenous doses of acetazolamide,
D000137:Acid-Base Imbalance / Q000097:blood / Q000134:cerebrospinal fluid; D000208:Acute Disease; D000818:Animals; D001783:Blood Flow Velocity; D001921:Brain / Q000378:metabolism*; D002245:Carbon Dioxide / Q000097:blood; D004114:Dimethadione; D004285:Dogs; D005260:Female; D006863:Hydrogen-Ion Concentration; D006935:Hypercapnia / Q000378:metabolism; D008297:Male; D009132:Muscles / Q000378:metabolism
D002245:Carbon Dioxide; D004114:Dimethadione