Ionic mechanisms of cerebrospinal fluid acid-base regulation.
This review emphasizes the importance of strong ions in the regulation of cerebrospinal fluid (CSF) acid-base balance. In a solution like CSF that is devoid of nonbicarbonate buffers. [H+] and [HCO-3] are dependent variables, the independent variables being the CO2 partial pressure (PCO2) and the strong ion difference. Any measureable changes in CSF [HCO-3] and any change in [H+] that occur independent of changes in PCO2 must be accompanied by, if not caused by, changes in strong ions. The role of H+ and HCO-3 vs. strong ions in the ionic mechanisms of CSF acid-base regulation is unknown. For example, these mechanisms could depend only on changes in strong ions that accompany acid-base disorders, or they could be triggered by changes in [H+] or PCO2. These ideas are presented within the context of current concepts concerning the relationship of CSF to brain interstitial fluid (ISF) and the importance of choroid plexus and blood-brain barrier mechanisms in determining CSF and ISF ionic composition. Studies concerning CSF strong ions in normal and abnormal acid-base states are reviewed.
D000136:Acid-Base Equilibrium; D000137:Acid-Base Imbalance / Q000134:cerebrospinal fluid; D000818:Animals; D001639:Bicarbonates / Q000134:cerebrospinal fluid; D001696:Biomechanical Phenomena; D002245:Carbon Dioxide / Q000134:cerebrospinal fluid; D006801:Humans; D006859:Hydrogen / Q000134:cerebrospinal fluid; D007477:Ions / Q000134:cerebrospinal fluid*; D010313:Partial Pressure
D001639:Bicarbonates; D007477:Ions; D002245:Carbon Dioxide; D006859:Hydrogen