Investigation of substance P transport across the blood-brain barrier

The transport of substance P (SP) was investigated using the bovine brain microvessel endothelial Cell Culture model of the blood-brain barrier (BBB). The samples were derivatized precolumn with naphthalene dialdehyde, then analyzed by cyclodextrin-modified micellar electrokinetic chromatography with laser-induced fluorescence detection. SP crossed the BBB in both the apical-to-basolateral and basolateral-to-apical directions through an active transport mechanism. The transport of SP from the apical side was demonstrated to be via transcytosis. The N-terminal (SP(1-4)) and C-terminal (SP(3-11)) fragments were also found to permeate the BBB from the apical side.