Low doses of hyperbaric oxygenation effectively decrease the size of necrotic zone in rats with experimental...

Area of Science:

• Cardiovascular Research
• Hyperbaric Medicine
• Myocardial Infarction

Background:

• Myocardial infarction (MI) involves irreversible damage to heart muscle.
• Assessing the impact of interventions on infarct size is crucial for treatment development.
• Hyperbaric oxygenation (HBO) is explored for its therapeutic potential in ischemic conditions.

Purpose of the Study:

• To investigate the effect of a single hyperbaric oxygenation session on infarct size in a rat model.
• To compare the efficacy of different oxygen pressures (0.02 MPa and 0.1 MPa) during HBO therapy.
• To analyze the impact of HBO on the risk, ischemic, and necrotic zones of the myocardium.

Main Methods:

• Myocardial infarction was induced in rats by ligating the left coronary artery.
• Hyperbaric oxygenation (60-minute session) was administered 3 hours post-occlusion.
• Planimetric evaluation was used to measure the size of risk, ischemic, and necrotic zones.

Main Results:

• HBO significantly reduced the risk zone median from 31.7% to 25% of left ventricle weight.
• At 0.02 MPa, HBO shifted the ischemia-to-necrosis ratio from 1.7:1 to 2:1, decreasing necrotic area.
• At 0.1 MPa, HBO altered the ratio to 0.6:1, indicating a different effect on tissue zones.

Conclusions:

• Hyperbaric oxygenation demonstrates a positive effect on myocardium during total coronary artery occlusion.
• Lower oxygen pressure (0.02 MPa) during HBO therapy appears more beneficial for limiting infarct expansion.
• HBO promotes a favorable redistribution of ischemic and necrotic areas, reducing overall infarct size.