Changes in Blood-Brain Permeability during Pharmacologically induced Convulsions

Abstract

Disturbances of the normal functions of the “blood–brain barrier” are well known following a large variety of pathological stresses. Relatively less attention has been directed toward the transient alterations in solute exchange between blood and brain that may accompany less destructive stimuli. Such alterations may be significant in the pathogenesis of certain disorders of central nervous system function. In this chapter, experiments on temporary alterations in the entry of sulfate into brain were found to accompany pharmacologically-induced convulsions. Marked concomitant changes in brain surface pH, oxygen and carbon dioxide tensions were recorded by direct measurement during the convulsion. As a result of these observations, the influence of hypercapnia and acidosis on brain vascular permeability was studied in some detail. Sulfate and albumin were employed as indicators. The chapter mainly deals with: The effects of pharmacologically induced convulsions on the penetration of sulfate into cat brain, the effect of Metrazol on the penetration of albumin into cat brain and the effect of hypercapnia on the penetration of sulfate and albumin into the brain. As a conclusion, the chapter states that hypercarbia had a profound effect on vascular permeability in some regions of the brain while sparing others.