Calcitonin gene-related peptide prevents blood-brain barrier injury and brain edema induced by focal cerebral ischemia reperfusion

Regul Pept. 2011 Nov 10;171(1-3):19-25. doi: 10.1016/j.regpep.2011.05.014. Epub 2011 Jun 28.

Abstract

Cerebral ischemia is one of the diseases that most compromise the human species. Therapeutic recovery of blood-brain barrier (BBB) disruption represents a novel promising approach to reduce brain injury after stroke. To determine the effects of calcitonin gene-related peptide (CGRP) on the BBB participate in stroke progression, rat cerebral ischemia reperfusion injury was induced by a 2-hour left transient middle cerebral artery occlusion (MCAO) using an intraluminal filament, followed by 46h of reperfusion. CGRP (1μg/ml) at the dose of 3μg/kg (i.p.) was administered at the beginning of reperfusion. Subsequently, 48h after MCAO, arterial blood pressure, infarct volume, water content, BBB permeability, BBB ultrastructure, levels of aquaporin-4 (AQP4) and its mRNA were evaluated. CGRP could reduce arterial blood pressure (P<0.001), infarct volume (P<0.05), cerebral edema (P<0.01), BBB permeability (P<0.05), AQP4 mRNA expression (P<0.05) and AQP4 protein expression (P<0.01). Furthermore, CGRP treatment improved ultrastructural damage of capillary endothelium cells and decreased the loss of the tight junction observed by transmission electronic microscopy (TEM) after 46h of reperfusion. Our findings show that CGRP significantly reduced postischemic increase of brain edema with a 2-hour therapeutic window in the transient model of focal cerebral ischemia. Moreover, it seems that at least part of the anti-edematous effects of CGRP is due to decrease of BBB disruption by improving ultrastructural damage of capillary endothelium cells, enhancing basal membrane, and inhibiting AQP4 and its mRNA over-expression. The data of the present study provide a new possible approach for acute stroke therapy by administration of CGRP.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blood Pressure / drug effects
  • Blood-Brain Barrier / drug effects
  • Blood-Brain Barrier / injuries
  • Blood-Brain Barrier / ultrastructure*
  • Brain Edema / prevention & control*
  • Brain Ischemia / pathology
  • Calcitonin Gene-Related Peptide / administration & dosage
  • Calcitonin Gene-Related Peptide / pharmacology*
  • Infarction, Middle Cerebral Artery
  • Male
  • Microscopy, Electron, Transmission
  • Permeability / drug effects
  • Rats
  • Rats, Wistar
  • Reperfusion Injury / prevention & control*

Substances

  • Calcitonin Gene-Related Peptide