The effect of heat shock on immediate post-preservation lung function

Area of Science:

• Biomedical Engineering
• Physiology
• Cellular Biology

Background:

• Heat shock proteins (HSPs) are induced by hyperthermia and offer cytoprotection against various injuries, including ischemia.
• HSPs are conserved across species and play a role in cellular stress response and repair mechanisms.
• Pulmonary preservation is critical for lung transplantation success, with ischemia-reperfusion injury being a major concern.

Purpose of the Study:

• To investigate if pre-harvest heating of donor animals enhances pulmonary preservation.
• To determine the effect of induced heat shock proteins on lung function post-storage.
• To evaluate the protective potential of transient hyperthermia against ischemia in harvested lungs.

Main Methods:

• New Zealand White rabbits were subjected to radiant heating (42.5-43.5°C) 8 hours before lung harvest.
• Lungs were stored for 18 hours at 4°C without initial flush.
• Ex vivo perfusion was performed, and measurements included blood gases, pulmonary artery (Ppa) and airway (P(aw)) pressures, and wet/dry ratios (W/D).

Main Results:

• All heated animals exhibited HSP72, while controls did not.
• No significant differences in oxygenation (PO2) were observed between heated and control groups in two experimental setups.
• Pulmonary artery pressures and wet/dry ratios showed no significant improvement in the heated group compared to controls.

Conclusions:

• Transient hyperthermia prior to organ harvest does not appear to improve pulmonary preservation in this rabbit model.
• The induction of HSP72 did not translate to measurable functional benefits in the harvested lungs.
• Further research may be needed to explore alternative methods or optimize hyperthermia protocols for enhanced lung preservation.