Passage of vasoactive intestinal peptide across the blood-brain barrier
Özet
We investigated the ability of vasoactive intestinal peptide (VIP) to cross the blood-brain barrier (BBB), the interface between the peripheral circulation and central nervous system (CNS). VIP labeled with I-131 (I-VIP) and injected intravenously into mice was taken up by brain as determined by multiple-time regression analysis. Excess unlabeled VIP was unable to impede the entry of I-VIP, indicating that passage is by nonsaturable transmembrane diffusion. High pressure liquid chromatography (HPLC) showed the radioactivity entering the brain to be intact I-VIP. After intracerebroventricular (i.c.v.) injection, I-VIP was sequestered by brain, slowing its efflux from the CNS. In summary, VIP crosses the BBB unidirectionally from blood to brain by transmembrane diffusion
