The cerebrospinal fluid production rate in the experimentally induced edematous brain and influences of dexamethasone upon it.

Cerebral edema must be closely implicated in the cerebrospinal fluid production rate and corticosteroid, which is effective to reduce cerebral edema, must have influence upon the rates of the cerebrospinal fluid production in the edematous brain. There has been a little of previous studies which dealt with the influence of corticosteroid upon the cerebrospinal fluid production rate, but little of reports of studies of the changes of the cerebrospinal fluid production rate in the edematous brain as yet. In this series of experiments the change of the cerebrospinal fluid production rate in the experimentally induced edematous brain and the influence of dexamethasone upon it were studied in dogs by means of ventriculo-cisternal perfusion technique. The dog with his head shaken by the newly designed machine was anesthetized and the lateral ventricle and the cisterna magna were punctured 24 hours after shaking. The artificial cerebrospinal fluid containing of inulin as a tracer was pumped into the lateral ventricle of two groups of dogs with and without intravenously administered dexamethasone, and droplets out of the cisterna magna were sampled. Results by this experiment were the reduction of the cerebrospinal fluid production rate in the edematous brain and the further reduction of it in the edematous brain after the dexamethasone administration. This suggests that dexamethasone may act closely on water-ion transpot in the cerebrospinal fluid secretion system.