title: Cerebral interstitial fluid acid-base status follows arterial acid-base perturbations.
abstract: Cerebral interstitial fluid (ISF) pH of ventral medulla or thalamus, cisternal cerebrospinal fluid (CSF) pH, and arterial blood pH, PCO2, and [HCO-3] were measured in chloralose-urethan-anesthetized, gallamine-paralyzed New Zealand White rabbits during 30-min episodes of either HCl or NaHCO3 intravenous infusions. ISF pH was measured continuously with glass microelectrodes (1- to 2-microns tip diameter). Cisternal CSF pH was measured continuously with an indwelling pH probe (1-mm tip diameter). Both ventral medullary and thalamic ISF [H+] changed significantly, whereas arterial PCO2 remained constant. CSF [H+] did not change. We conclude from these data that 1) changes in blood acid-base conditions are rapidly reflected in cerebral ISF and 2) transient differences in [H+] and [HCO-3] can exist between cerebral ISF and CSF.
mesh_terms: D000138:Acidosis / Q000097:blood / Q000134:cerebrospinal fluid / Q000378:metabolism*; D000471:Alkalosis / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000378:metabolism*; D002245:Carbon Dioxide / Q000097:blood; D005110:Extracellular Space / Q000378:metabolism*; D005260:Female; D006863:Hydrogen-Ion Concentration; D008297:Male; D008526:Medulla Oblongata / Q000378:metabolism; D011817:Rabbits; D013788:Thalamus / Q000378:metabolism
chemical_list: D002245:Carbon Dioxide