Drug transition through the blood-brain barrier after the retrograde intraarterial application

Transition of xenobiotics from blood into brain tissue is limited by the blood-brain barrier (BBB), a very selective functional barrier that excludes penetration of various substances, while allowing essential nutrients to enter into CNS. Transport of drugs through the intact BBB depends of their physico-chemical characteristics, the way of drug application and of anatomical and functional integrity of the barrier. The aim of this work was to examine penetration of quinine and lysinacetylsalicilate in vivo through the rat BBB, after the intraarterial injection via the a. axillaris in the course to CNS. The experiment was done on anaesthetized Wistar rats, body weight 200-300 g. Test animals received injection of quinine (25 mg/kg) or LAS (90 mg/kg). Blood from the left jugular vein and brain samples (brain stem, cerebellum, right and left cerebral hemispheres) were taken in four minutes period. Quinine concentrations in rat brain were higher than in blood (ratio between blood/brain concentration was <1) while LAS concentrations in blood were permanently higher, according to their liposolubility. Maximal concentration in the brain tissue of both drugs are time dependent which indicated the useless of an active transport.