CENTRAL-NERVOUS-SYSTEM DISTRIBUTION OF FIBROBLAST GROWTH-FACTOR INJECTED INTO THE BLOOD-STREAM

It has been shown that fibroblast growth factors (FGFs) protect hypoca mpal CAI cells from the effects of transient ischemia when injected ei ther intraventrically or intravenously. The effectiveness of the syste mic treatment seems to suggest that FGFs cross the blood-brain barrier to some extent. The appearance of basic fibroblast growth factor (bFG F) in the rat central nervous system after systemic administration hav e been autoradiographically examined using a C-14 uniformly labeled pr eparation. Our results show that, two hours after a systemic bolus adm inistration, bFGF spots in several populations of neuronal and in non- neural cells except in glial cells. Label accumulation was imperceptib le when either C-14-bFGF was heated previously to the systemic injecti on or was co-administered with an excess of unlabeled bFGF. Our result s indicate the existence of a saturable transport system of FGFs acros s the blood-brain barrier.