Annexin A5 scintigraphy of forearm as a novel in vivo model of skeletal muscle preconditioning in humans

Circulation. 2005 Jan 18;111(2):173-8. doi: 10.1161/01.CIR.0000151612.02223.F2. Epub 2004 Dec 27.

Abstract

Background: Nonlethal ischemia and reperfusion reduce ischemia-reperfusion-induced cell death, a phenomenon called ischemic preconditioning. In animal models, this potent endogenous protection is mimicked in vivo by administration of adenosine. In humans, exploitation of ischemic preconditioning is hindered by the lack of an appropriate in vivo model to study this phenomenon. To solve this problem, we aimed to set up an easy-to-use human in vivo model to study ischemic or pharmacological preconditioning.

Methods and results: Healthy male volunteers performed unilateral ischemic handgrip. At reperfusion, we intravenously injected technetium-99m-labeled Annexin A5, a presumed marker of ischemic injury, and we imaged both forearms and hands simultaneously with a gamma camera. Region of interest analysis (counts per pixel) and subsequent calculation of the percentage difference in radioactivity between experimental and control hands (thenar muscle; mean+/-SE) revealed significant uptake to the ischemically exercised tissue (26+/-3% at 4 hours after reperfusion; P<0.05). This selective localization of Annexin A5 was reduced by ischemic preconditioning (10 minutes of ischemia plus reperfusion before ischemic exercise) or by infusion of adenosine into the brachial artery to 6+/-1% and 10+/-3%, respectively (P<0.05 versus ischemic exercise alone), resembling observations in animal models with infarct size as an end point. Appropriate control experiments supported our conclusion.

Conclusions: Annexin A5 scintigraphy can be applied to test pharmacological or physiological interventions for their ability to prevent ischemia-reperfusion injury.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine / administration & dosage
  • Adenosine / pharmacology
  • Adenosine / therapeutic use
  • Adolescent
  • Adult
  • Annexin A5 / administration & dosage
  • Annexin A5 / analysis*
  • Annexin A5 / pharmacokinetics
  • Apoptosis
  • Drug Administration Schedule
  • Exercise Test
  • Forearm / blood supply*
  • Forearm / diagnostic imaging
  • Hand / blood supply
  • Hand / diagnostic imaging
  • Hand Strength
  • Humans
  • Hydrazines
  • Hyperemia / diagnostic imaging
  • Injections, Intra-Arterial
  • Injections, Intravenous
  • Ischemia / diagnostic imaging*
  • Ischemia / pathology
  • Ischemic Preconditioning*
  • Male
  • Membrane Lipids / metabolism
  • Muscle, Skeletal / blood supply
  • Muscle, Skeletal / diagnostic imaging
  • Nicotinic Acids
  • Phentolamine / pharmacology
  • Phosphatidylserines / metabolism
  • Protein Binding
  • Radionuclide Imaging
  • Recombinant Proteins / administration & dosage
  • Recombinant Proteins / analysis
  • Recombinant Proteins / pharmacokinetics
  • Reperfusion Injury / diagnostic imaging*
  • Reperfusion Injury / pathology
  • Reperfusion Injury / prevention & control
  • Technetium Tc 99m Aggregated Albumin
  • Vasodilation / drug effects

Substances

  • 6-hydrazinopyridine-3-carboxylic acid
  • Annexin A5
  • Hydrazines
  • Membrane Lipids
  • Nicotinic Acids
  • Phosphatidylserines
  • Recombinant Proteins
  • Technetium Tc 99m Aggregated Albumin
  • Adenosine
  • Phentolamine