Increased Hemoglobin Oxygen Affinity With 5-Hydroxymethylfurfural Supports Cardiac Function During Severe Hypoxia

Area of Science:

• Physiology
• Biochemistry
• Pharmacology

Background:

• Hypoxia necessitates physiological adaptations in oxygen (O2) transport and utilization.
• Natural products like aromatic aldehydes can enhance hemoglobin-O2 affinity, a counterintuitive strategy for improving O2 delivery during hypoxia.
• 5-Hydroxymethylfurfural (5-HMF), a Maillard reaction product, is known to affect hemoglobin-O2 affinity.

Purpose of the Study:

• To investigate the therapeutic potential of 5-HMF on left ventricular cardiac function (LVCF) during hypoxic conditions.
• To explore the mechanism by which 5-HMF might improve cardiac performance under hypoxia.

Main Methods:

• Anesthetized Golden Syrian hamsters received intravenous 5-HMF (100 mg/kg) and were subjected to stepwise hypoxia (15%, 10%, 5% O2).
• Left ventricular cardiac function (LVCF) was assessed using a conductance catheter for pressure-volume measurements.
• Heart hypoxic areas were identified using pimonidazole staining.

Main Results:

• 5-HMF significantly improved cardiac indices, including stroke volume (SV), cardiac output (CO), ejection fraction (EF), and stroke work (SW) compared to the vehicle group.
• At 5% O2, 5-HMF administration resulted in substantial increases in SV (53%), CO (42%), EF (33%), and SW (51%).
• The observed improvements in LVCF were attributed to volume-dependent effects, not direct pharmacological actions or changes in heart rate, suggesting increased hemoglobin-O2 affinity.

Conclusions:

• Naturally occurring aromatic aldehydes, exemplified by 5-HMF, can modify hemoglobin-O2 affinity.
• 5-HMF demonstrates promising therapeutic potential for increasing oxygen delivery during hypoxic hypoxia.
• These findings support the use of 5-HMF as a strategy to mitigate cardiac dysfunction in hypoxic environments.