LINOLEIC-ACID PASSAGE THROUGH THE BLOOD-BRAIN-BARRIER AND A POSSIBLE EFFECT OF AGE

It has already been established that the blood-brain barrier is readil y crossed by unsaturated fatty acids, while saturated fatty acid trans port appears to be protein mediated. When the passage of the fatty aci ds is tested in vivo by using perfusion buffers containing both linole ate and palmitate in different concentrations, linoleate is able to de crease the palmitate passage, while palmitate increases the linoleate passage. These results could be related to the effect of two fatty aci ds on the ratio between the fatty acids bound to the serum albumin and the free fatty acid pool, which is only available for transport throu gh membranes. However, on the basis of some results obtained with aged rats, the possibility that a relationship may exist between palmitate and linoleate during their passage through the BBB is discussed. More over, it seems likely that in aged rats a moderate modification for fa tty acids takes place in the BBB.