Most peptides have not proved useful as neuroactive drugs because they are blocked by the blood-brain barrier and do not reach their receptors within the brain. Intraperitoneally administered L-serinyl β-D-glucoside analogues of [Met5]enkephalin (glycopeptides) have been shown to be transported across the blood-brain barrier to bind with targeted μ- and δ-opioid receptors in the mouse brain. The opioid nature of the binding has been demonstrated with intracerebroventricularly administered naloxone. Paradoxically, glucosylation decreases the lipophilicity of the peptides while promoting transport across the lipophilic endothelial layer. It is suggested that glucose transporter GLUT-1 is responsible for the transport of the peptide message. Profound and long-lasting analgesia has been observed in mice (tail-flick and hot-plate assays) with two of the glycopeptide analogues when administered intraperitoneally.
|Original language||English (US)|
|Number of pages||5|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - Jul 19 1994|
- drug delivery
- opioid receptor
ASJC Scopus subject areas