D-[Ala1]-peptide T-amide is transported from blood to brain by a saturable system.
It is becoming increasingly evident that peptides can cross the blood-brain barrier. The entry into the central nervous system of a commercially available analog of Peptide T, an octapeptide derived from the human immunodeficiency virus envelope glycoprotein 120, was studied in several experiments. It was found that 125I-Peptide T analog given intravenously in the periphery entered the brain in an intact form, as confirmed by HPLC, to a greater extent than did the labeled albumin control. This entry occurred despite the very low lipid solubility, measured by the octanol/buffer partition coefficient, for the iodinated analog. The rate of entry was decreased by unlabeled Peptide T analog, but not by iodo-tyrosine. Saturable transport out of the brain was not observed after intraventricular administration. Thus, results with 125I-Peptide T analog indicate that saturable systems can transport peptides from the blood into the central nervous system.
Veterans Administration Medical Center, New Orleans, LA 70146.
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Barrera
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Kastin
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Banks
D000818:Animals; D001812:Blood-Brain Barrier; D002851:Chromatography, High Pressure Liquid; D007457:Iodine Radioisotopes; D007700:Kinetics; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009842:Oligopeptides / Q000097:blood / Q000378:metabolism*; D015717:Peptide T; D013668:Technetium Tc 99m Aggregated Albumin
D007457:Iodine Radioisotopes; D009842:Oligopeptides; D013668:Technetium Tc 99m Aggregated Albumin; D015717:Peptide T; C055175:peptide T amide