title: Distribution of H+ and HCO3 minus between CSF and blood during metabolic alkalosis in dogs.
abstract: In anesthetized, paralyzed dogs ventilated to maintain a normal PaCO2, metabolic alkalosis was induced and held constant over 6 h by infusion of sodium bicarbonate. Determination of pH, PCO2, (HCO3 minus), and (lactate) in cisternal and lumbar cerebrospinal fluid (CSF) and in arterial plasma together with measurement of the CSF/plasma DC potential differences permitted calculation of the electrochemical potential difference (mu) for H+ and HCO3 minus; measurements were made prior to induction of metabolic alkalosis at pHa equal to 7.40, as soon after induction as stable arterial values were achieved and 3, 4.5, and 6 h thereafter. A steady state for ion distribution was reached by 4.5 h. Values of mu for H+ and HCO3 minus returned to +0.1 and +0.9 mV of control at 6 h for cisternal CSF and +0.6 and minus 0.4 mV for lumbar CSF. This return of muH+ and muHCO3 minus close to control in the steady state is compatible with passive distribution of these ions between brain extracellular fluid and blood.
mesh_terms: D000136:Acid-Base Equilibrium; D000471:Alkalosis / Q000378:metabolism*; D000818:Animals; D001639:Bicarbonates / Q000097:blood / Q000134:cerebrospinal fluid; D001692:Biological Transport; D001769:Blood; D001921:Brain / Q000378:metabolism; D002245:Carbon Dioxide / Q000097:blood / Q000134:cerebrospinal fluid; D002555:Cerebrospinal Fluid; D004285:Dogs; D004594:Electrophysiology; D007773:Lactates / Q000097:blood / Q000134:cerebrospinal fluid; D013997:Time Factors
chemical_list: D001639:Bicarbonates; D007773:Lactates; D002245:Carbon Dioxide