Abstract
Artificial hyperventilation of anesthetized dogs produces apart from the well known decreases in blood and CSF [H+] and pCO2, also changes in the lactate concentrations. In blood lactate concentrations increase very rapidly; in CSF an increase is seen only progressively and after some time. It is suggested that this extra lactate in CSF finds its origin in the nervous tissue. This lactate can have a part in the progressive lowering which is seen in the bicarbonate concentration in CSF during sustained hyperventilation.