Significance of Different Routes of Introduction on the Transport of Substances into the Brain 1

Summary

Sulfate, cycloleucine, and 3-O-methyl-glucose were introduced into the brain by three different routes: (a) brain perfusion, (b) blood injection, and (c) blood injection and blood perfusion simultaneously.

The value attained in the nervous tissue with sulfate, which is considered an extracellular marker, when administered by the two combined routes, was equal to the addition of data obtained by each route separately. Using the combined procedure (c) for cycloleucine, a higher value than that calculated from the sum of procedures (a) plus (b) was reached. The data of the combined introduction for methyl-glucose were in the range of those obtained by blood injection alone.

The significance of different routes of administration on the uptake of substances into the brain is discussed.