Effect of an anion transport inhibitor on blood-brain barrier lesions during acute hypertension. Possible prevention of transendothelial vesicular transport.

Opening of the blood-brain barrier (BBB) by a hypertensive insult comprises the formation of endothelial micropinocytosis. Constricted vessels are less vulnerable to the insult. In the present study SITS (4-acetamido-4'-isothiocyano-stilbene-2,2'-disulfonic acid disodium) was shown to prevent leakage across the BBB into the brain parenchyma following a hypertensive insult induced by a local increase of the intraluminal pressure in anesthetized rats and by i.v. administration of adrenaline or bicuculline in conscious unrestrained animals. Since SITS induced an increase in cerebral blood flow the protection cannot be explained by a constrictory action on the cerebral vessels. SITS is a drug with complex action on the cell membrane including an inhibitory effect on anion transport mechanisms and on some c-AMP mediated processes. It is possible that the protection of BBB observed in the present study is connected to a reduction of c-AMP but membrane stabilizing effect can at present not be excluded.