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Vascular Permeability to Hemorphins in the Central Nervous System

An Experimental Study Using 125I-Hemorphin-7 in the Rat
  • H. S. Sharma
  • K. Sanderson
  • E.-L. Glämsta
  • Y. Olsson
  • F. Nyberg
Part of the Advances in Behavioral Biology book series (ABBI, volume 46)

Summary

Blood-brain barrier (BBB) permeability to hemorphin-7, an endogenous morphine like peptide derived from haemoglobin, is unknown. The present investigation was undertaken to examine the microvascular permeability to 125I-labelled hemorphin-7 in different regions of the brain and spinal cord in normal male rats. In addition, the influence of hemorphin on brain water content and morphology of cerebral microvessels was examined at ultrastructural level. Rats received 1251-sodium instead of hemorphin served as controls. The BBB permeability to 1251-labelled hemorphin-7 was significantly higher in various brain and spinal cord regions at 3 min (35–70%) and 15 min (150–170%) after administration compared to 1251-sodium. On the other hand, the microvascular permeability to another form of hemorphin, Leu-Val-Val-hemorphin-7 was very close to that of radioactive iodine at both 3 or 15 min circulation period. Infusion of hemorphin-7 however, did not influence the regional brain water content or ultrastructure of the cerebral microvessels compared to either radioactive iodine or Leu-Val-Val-hemorphin-7. These results suggest that hemorphin-7 has the capacity to cross the BBB of normal rats without affecting brain edema formation or cerebrovascular ultrastructure.

Keywords

Radioactive Iodine Brain Water Content Microvascular Permeability Spinal Cord Region Cerebral Microvessels 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Résumé

L’hémorphine 7 est un peptide dérivé de l’hémoglobine, de la famille de la morphine. La perméabilité de la barrière hémato-encéphalique (BHE) de ce peptide n’est pas connue et cette étude avait pour but d’évaluer la perméabilité microvasculaire de l’hémorphine 7 marquée à l’iode 125 dans différentes régions du cerveau et de la moelle épinière chez des rats normaux males. De plus, les effets de l’hémorphine sur la régulation hydrique du cerveau ainsi que sur la morphologie des microvaisseaux a été étudiée. La perméabilité de la BHE du peptide marqué est supérieure dans de nombreuses régions du cerveau et de la moelle épinière en comparaison d’iode 125 utilisé comme temoin: 35 à 70%, 3 min après l’administration du peptide et 150 a 170% après 15 min. Par contre, la perméabilité microvasculaire du peptide leu-val-val-hémorphine 7 est très proche de celle de l’iode 125 témoin après les mêmes temps de circulation. Toutefois, l’administration de l’hémorphine 7 ne semble pas provoquer de changements de l’équilibre hydrique du cerveau ni de modifications de l’ultrastructure des microvaisseaux cérébraux par rapport aux témoins, iode 125 ou leu-val-val-hémorphine 7. Ces résultats suggèrent que l’hémorphine peut traverser la BHE de rats normaux sans provoquer d’oedème cérébral ni de modification de l’ultrastructure microvasculaire

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Copyright information

© Springer Science+Business Media New York 1996

Authors and Affiliations

  • H. S. Sharma
    • 1
    • 2
  • K. Sanderson
    • 1
  • E.-L. Glämsta
    • 1
  • Y. Olsson
    • 2
  • F. Nyberg
    • 1
  1. 1.Department of Pharmaceutical Biosciences Biomedical CentreUppsala UniversitySweden
  2. 2.Laboratory of NeuropathologyUniversity HospitalUppsalaSweden

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