Effects of isoflurane and sevoflurane on the neutrophil myeloperoxidase system of horses.

This research article investigates how volatile anaesthetics affect the oxidative response of polymorphonuclear neutrophils in horses, with specific focus on degranulation and myeloperoxidase activity.

Introduction

• The study explores the influence of isoflurane and sevoflurane, two types of volatile anaesthetics, on the myeloperoxidase (MPO) system of polymorphonuclear neutrophils (PMNs) in horses.
• The researchers investigated how these anaesthetics affect the degranulation of total and active myeloperoxidase from horse PMNs.
• MPO is an enzyme found in PMNs that plays a crucial role in the body’s immune response.
• Understanding how these anaesthetics interact with the body’s immune response can provide valuable insight into their full effects and potential side effects.

Methodology

• Horse blood was incubated in different concentrations of isoflurane or sevoflurane and PMNs were stimulated using cytochalasin B and N-formyl-méthionyl-leucyl-phenylalanine.
• After stimulation, the plasma was harvested to measure total and active MPO using an enzyme-linked immunosorbent assay (ELISA) and specific immunological extraction followed by enzymatic detection.
• The researchers also evaluated the effects of the anaesthetics on the pure MPO enzyme’s peroxidase and chlorination activity.

Results

• The results show that isoflurane and sevoflurane had inconsistent effects on total MPO release. However, irrespective of the inconsistency on total MPO release, both anaesthetics were seen to reduce the active MPO release.
• Additionally, both anaesthetics have shown a direct inhibition effect on the peroxidase and chlorination activity of the MPO enzyme.
• A persistent interaction with the enzyme MPO was found with isoflurane but not with sevoflurane.

Conclusion

• This research adds to the understanding of how volatile anaesthetics affect the immune response, particularly the function of neutrophils.
• This can be helpful in understanding how to mitigate negative effects and improve the management of anesthesia in horses and possibly other animals.