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Updated: Jul 30, 2026
Induction and Assessment of Ischemia-reperfusion Injury in Langendorff-perfused Rat Hearts
Published on: July 27, 2015
Effects of endotoxin on neutrophil-mediated I/R injury in isolated perfused rat hearts
B P Lipton1, A P Bautista, J B Delcarpio
1Department of Physiology and Cell Biology, Louisiana State University Medical Center, New Orleans, Louisiana 70112, USA.
Abstract:
With the use of a syngeneic model, we demonstrate that rat polymorphonuclear neutrophils (PMNs) exacerbate ischemia-reperfusion injury in the isolated rat heart. However, PMNs (19 x 10(6) cells) from lipopolysaccharide (LPS)-treated rats (LPS-PMNs; 100 mg/kg administered 7 h before exsanguination) induce less reperfusion injury in the isolated heart. Average recovery of left ventricular developed pressure after 20 min of ischemia and 60 min of reperfusion was 51 +/- 4% in hearts receiving PMNs from saline-treated control rats (saline-PMNs) versus 78 +/- 2% in hearts receiving LPS-PMNs. Ischemic hearts reperfused with LPS-PMNs recovered to the same extent as did hearts reperfused with Krebs buffer only. LPS-PMNs and saline-PMNs showed no difference in basal or phorbol ester-induced superoxide production. Whereas twice the number of LPS-PMNs was positive for nitroblue tetrazolium, the percent positive for L-selectin, a receptor integral in PMN-adhesion to endothelium, was 50% less in LPS-PMNs than in controls. After reperfusion, three-fourths of the saline-PMNs remained within the hearts, whereas only one-fourth of LPS-PMNs were trapped. These data suggest that PMNs from LPS-treated rats do not exacerbate ischemia-reperfusion injury as do control PMNs, possibly, due to impaired PMN adhesion to endothelium as a result of decreased L-selectin receptors.
Insights
Rat polymorphonuclear neutrophils (PMNs) normally worsen ischemia-reperfusion injury. However, PMNs from lipopolysaccharide (LPS)-treated rats show reduced injury, possibly due to impaired adhesion.
Area of Science:
- Cardiovascular Science
- Immunology
- Cell Biology
Background:
- Ischemia-reperfusion (I/R) injury is a significant clinical problem.
- Polymorphonuclear neutrophils (PMNs) play a critical role in I/R injury.
- The precise mechanisms by which PMNs modulate I/R injury require further elucidation.
Purpose of the Study:
- To investigate the effect of lipopolysaccharide (LPS)-modulated PMNs on I/R injury in an isolated rat heart model.
- To explore the functional and molecular differences between PMNs from control and LPS-treated rats.
Main Methods:
- Isolated rat hearts subjected to 20 minutes of ischemia and 60 minutes of reperfusion.
- Hearts were reperfused with either saline-treated rat PMNs (saline-PMNs) or LPS-treated rat PMNs (LPS-PMNs).
- Assessed left ventricular developed pressure (LVDP) recovery, superoxide production, nitroblue tetrazolium (NBT) positivity, L-selectin expression, and PMN trapping.
Main Results:
- LPS-PMNs significantly reduced I/R injury compared to saline-PMNs, with LVDP recovery similar to hearts reperfused with buffer alone.
- No significant differences were observed in basal or phorbol ester-induced superoxide production between LPS-PMNs and saline-PMNs.
- LPS-PMNs exhibited 50% less L-selectin expression and reduced trapping within the heart post-reperfusion compared to saline-PMNs.
Conclusions:
- PMNs from LPS-treated rats attenuate ischemia-reperfusion injury in the isolated rat heart.
- This protective effect may be attributed to decreased L-selectin expression on LPS-PMNs, leading to impaired adhesion and reduced cardiac trapping.
- These findings suggest a potential therapeutic strategy targeting PMN adhesion in I/R injury.
