Integrity of blood-brain barrier during ethanol intoxication and withdrawal in the rat: normal glucose transfer and permeability to Na+ and Cl-.

The unidirectional brain uptake of 14-C-D-glucose, 24Na+ and 36Cl- was measured by the Oldendorf tissue uptake method in order to test whether severe ethanol intoxication or withdrawal affected the glucose transfer across the blood-brain barrier (BBB) or the integrity of the BBB to small ions. The Oldendorf technique rests upon the assumption that water is freely diffusible across the BBB, but in the present study a correction was applied, which takes into account the fact that the water extraction actually depends upon the different cerebral blood flow (CBF) in the groups. The 24Na+ and 36Cl- extraction values were about 1% as reported in other studies and this suggests that there was no major effect on the BBB reaction to small ions during severe ethanol intoxication or during withdrawal. The permeability surface area product did not deviate significantly from control values in any group and thus there was no indication that glucose transfer across the BBB differed during ethanol intoxication or withdrawal.