Sevoflurane Promotes Regeneration of the Endothelial Glycocalyx by Upregulating Sialyltransferase

Background During ischemia-reperfusion injury, the endothelial glycocalyx is damaged by oxidative stress-induced release of hydrogen peroxide, leading to decreased endothelium-dependent vasodilation. The regenerative effects of sevoflurane on the endothelial glycocalyx and endothelium-dependent vasodilation in oxidative stress remain unclear. Sialic acid, which is a component of the glycocalyx, plays a key role in antioxidant activity and is catalyzed by the sialyltransferase, ST6Gal-I. We hypothesized that ST6Gal-I is involved in the sevoflurane-induced promotion of endothelial glycocalyx restoration and endothelium-dependent vasodilation after oxidative stress. Materials and methods To assess vasodilation, isometric tension in the rat aorta was measured. Aortic rings were treated with 0.5 mM hydrogen peroxide pre-exposure or post exposure to sevoflurane, with or without an ST6Gal-I inhibitor. The rings were then used for glycocalyx imaging using fluorescein isothiocyanate-labeled lectin staining and for immunohistochemistry for ST6Gal-I. Results Vasodilation was significantly decreased by treatment with hydrogen peroxide compared to controls. Application of sevoflurane after treatment with hydrogen peroxide revived endothelium-dependent vasodilatation, whereas pretreatment with sevoflurane had no such effect. Sevoflurane after-treatment revived the intensity of fluorescence of the endothelial glycocalyx compared to the hydrogen peroxide group. However, pretreatment with sevoflurane had no such effect. Sevoflurane significantly upregulated the reduced expression of ST6Gal-I induced by hydrogen peroxide treatment. Conclusions Sevoflurane exerts regenerative effects on endothelium-dependent vasodilation and the endothelial glycocalyx following oxidative stress in the rat aorta.