Interaction between PCO2 and plasma [HCO-3] in regulation of CSF [HCO-3] in respiratory alkalosis and metabolic acidosis.

The results of studies presented may be interpreted in light of the dual contribution theory of regulation of CSF acid-base balance, indicating significant interaction between systemic and local CNS mechanisms in H+ homeostasis in the brain and CSF. Both systemic and local mechanisms are at work in H+ homeostasis in the brain and CSF and depending on the specific acid-base disorder or the duration of the imbalance one or the other of the two factors may be the dominant one in maintaining H+ levels in the "normal" range. These factors come into play only when there has been a change in central pH with the primary aim of bringing the CNS [H+] towards normal.