Evaluating the protective role of ischaemic preconditioning in rat hearts using a stationary small-animal SPECT imager and 99mTc-glucarate

Nucl Med Commun. 2008 Feb;29(2):120-8. doi: 10.1097/MNM.0b013e3282f29702.

Abstract

Objective: To examine the protective role of ischaemic preconditioning (IPC) in rat hearts using Tc-glucarate (GLA) and a stationary SPECT imager, FastSPECT.

Methods: Twenty-four rats with 30 min myocardial ischaemia and 150 min reperfusion (IR) were studied as follows. The IPC group (n=6) underwent IPC (five cycles of 4 min ligation of the left coronary artery and reflow) before IR. The control group (n=7) was treated by IR without IPC. The SPT group (n=6) was subjected to IPC and an adenosine antagonist, 8-(p-sulfophenyl)-theophylline (SPT). The vehicle group (n=5) received IPC and SPT carrier vehicle. GLA was delivered intravenously 30 min post-reperfusion, and 2-h dynamic cardiac images were acquired by FastSPECT.

Results: GLA showed 'hot-spot' accumulation in the ischaemic area-at-risk (IAR) and exhibited lower retention (% 5 min peak) in the IPC and vehicle groups (33.8+/-2.6 vs. 35.7+/-9.2, P>0.05) than in the control and SPT groups (63.1+/-5.3 vs. 54.8+/-4.8, P>0.05). The infarct size (% IAR) was larger in the control and SPT groups (48.2+/-6.3 vs. 41.7+/-6.3, P>0.05) than that in the IPC and vehicle groups (21.0+/-1.9 vs. 19.1+/-4.6, P>0.05). In terms of the ex-vivo IAR-to-normal radioactivity ratio, there was a statistical difference between the control and IPC groups (7.4+/-0.9 vs. 3.0+/-0.4), as well as the SPT and vehicle groups (7.4+/-1.0 vs. 3.4+/-0.5).

Conclusion: IPC offers cardioprotection and relates to the activation of adenosine receptors in rat hearts. FastSPECT GLA imaging is not only useful in detecting early ischaemia-reperfusion injury, but also valuable in evaluating cardioprotection.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Cardiotonic Agents / pharmacology
  • Glucaric Acid / analogs & derivatives*
  • Humans
  • Ischemic Preconditioning, Myocardial*
  • Male
  • Models, Statistical
  • Myocardium / pathology*
  • Organotechnetium Compounds*
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Purinergic P1 / metabolism
  • Reperfusion Injury / prevention & control
  • Risk
  • Time Factors
  • Tomography, Emission-Computed, Single-Photon / methods*

Substances

  • Cardiotonic Agents
  • Organotechnetium Compounds
  • Receptors, Purinergic P1
  • technetium Tc 99m glucarate
  • Glucaric Acid