THE EFFECTS OF ANTICONVULSANT DRUGS ON THE PERMEABILITY OF BRAIN CELLS TO D‐XYLOSE *

PREVIOUS studies of the effects of anticonvulsant drugs on the permeability of brain cells have been concerned mainly with the transport of ions (WOODBURY, KOCH and VERNADAKIS, 1958; KOCH and WOODBURY, 1958; TOWER, 1960), and reports of their effects on the transport of sugars into brain cells are limited. It was reported (LOWRY, PASSONNEAU, HASSELBERGER and SCHULZ, 1964) that the level of brain glucose was higher in phenobarbitone-treated mice than in control animals. This suggested that the transport of glucose into brain might be influenced by the anticonvulsant, and the finding that the ratio of brain glucose to serum glucose was increased by ‘Phenobarbitone anaesthesia’ (MAYMAN, GATFIELD and BRECKENRIDGE, 1964) further supported this possibility. In the investigations of LOWRY et al. (1964) and MAYMAN et al. (1964), however, the complicating influence of the metabolism of sugar was not dissociated from the process of its transport into the cell. This difficulty was obviated in a previous study in this laboratory (GILBERT, 1965) which suggested that xylose was transported into brain cells by a carrier mechanism, but the effects of anticonvulsants on xylose transport were not investigated at that time. The present investigation was undertaken to determine any effect of phenobarbitone, dimethadione, and diphenylhydantoin on the rate of transport of xylose into brain cells and to throw light on the mechanism of action of these drugs on brain cell membranes.