Peptides readily penetrate the blood-brain barrier: Uptake of peptides by synaptosomes is passive

R. Greenberg, C. E. Whalley, F. Jourdikian, I. S. Mendelson, R. Walter, K. Nikolics, D. H. Coy, A. V. Schally, A. J. Kastin

Research output: Contribution to journalArticlepeer-review

40 Scopus citations


The intracarotid artery quick injection technique of Oldendorf was utilized to determine the Brain Uptake Index (BUI) of radio-labeled peptides in comparison with 3H2 O or 14C-antipyrine as counterlabels. The normalized BUI values for 3H-MIF-I, 3H-α-MSH and 14C-AVP were 13.7, 9.6 and 13.0, respectively at 15 sec after injection consistent with their having readily penetrated the blood-brain barrier. The BUI values were similar, though somewhat increased, at 10 min postinjection consistent with their ready exit across the blood-brain barrier. At 15 sec after injection 0.5 ± 0.1%/g brain of the originally injected peptide label was recovered; and 0.1 ± 0.2%/g brain was recovered after 10 min. The label was distributed uniformly in the major brain regions at both times. However, the percentage of the originally injected label/g of pineal and pituitary gland tissue was 10-20 × increased as compared with the major brain regions as would be expected by their location outside the blood-brain barrier. The in vitro uptake of the radio-labeled peptides by synaptosomes prepared from the whole brain and the major brain regions was passive; it was not temperature dependent, nor was it Na+ dependent. However, the binding of the three peptides by the synaptosomes varied considerably: AVP>MSH>MIF : 50>5>1. The penetration of the blood-brain barrier by the three peptides is consistent with their having CNS effects.

Original languageEnglish (US)
Pages (from-to)151-158
Number of pages8
JournalPharmacology, Biochemistry and Behavior
Issue numberSUPPL. 1
StatePublished - 1976
Externally publishedYes


  • AVP
  • Blood-brain barrier
  • Brain uptake index
  • MIF-I
  • Passive uptake
  • Peptide binding
  • Peptides
  • Synaptosome uptake
  • α-MSH

ASJC Scopus subject areas

  • Biochemistry
  • Behavioral Neuroscience
  • Pharmacology


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