the cellular uptake at the blood-tissue interface of the blood-cerebrospinal fluid ( csf ) barrier to tyrosyl-3,5- [ 3h ] enkephalin- [ 5-l-leucine ] ( abbreviated to leu-enkephalin ) and of its synthetic analogue d-alanine2-tyrosyl-3,5- [ 3h ] enkephalin- [ 5-d-leucine ] ( abbreviated to d-ala2-d-leu5-enkephalin ) was studied in the isolated perfused choroid plexuses from the lateral ventricles of the sheep , using the rapid ( less than 30 s ) , single circulation , paired-tracer dilution technique , in which d- [ 14c ] -mannitol serves as an extracellular marker .
C0014294
leu-enkephalin
C0014298
enkephalin