Up-regulation of L Type Amino Acid Transporter 1 After Spinal Cord Injury in Rats

Acta Neurochir Suppl. 2008;102:385-8. doi: 10.1007/978-3-211-85578-2_74.

Abstract

Background: L-type amino acid transporter 1 (LAT1) is proposed to be a major nutrient transporter at the blood brain barrier. LAT1 requires the heavy chain of 4F2 cell surface antigen (4F2hc) for functional expression.

Methods: We investigated the expression of this heterodimeric transporter after traumatic spinal cord injury in rat by using immunohistochemical and western blot analyses.

Findings: LAT1 immunoreactivities were up-regulated in the capillary endothelia in close to the injury epicenter 24 hours after injury. It reached a peak at 48 hours after injury, and thereafter decreased. 4F2hc was abundant and unchanged all through the time course after SCI. Western blot analysis under reductive and non-reductive conditions showed that LAT1 and 4F2hc were conjugated as a heterodimeric transporter and the functional regulation was dependent on the light chain, LAT1.

Conclusions: We suggest that LAT1 may be transiently upregulated as part of the tissue-repair process after traumatic contusion injury in the spinal cord.

MeSH terms

  • Amino Acid Transport System L / metabolism*
  • Analysis of Variance
  • Animals
  • Disease Models, Animal
  • Female
  • Fusion Regulatory Protein 1, Heavy Chain / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Spinal Cord / metabolism
  • Spinal Cord Injuries / metabolism*
  • Spinal Cord Injuries / pathology
  • Spinal Cord Injuries / physiopathology
  • Time Factors
  • Up-Regulation / physiology*

Substances

  • Amino Acid Transport System L
  • Fusion Regulatory Protein 1, Heavy Chain