Preservation of Arterial Grafts with Bread Crust Extract Alleviates Endothelial Dysfunction in a Rodent Model of Revascularization In Vivo

Background: Ischemia/reperfusion (IR) injury is a well-recognized phenomenon that occurs in vascular grafts during coronary artery bypass surgery. Our previous study demonstrated that bread crust extract (BCE) protects against in vitro IR injury in vascular grafts. Therefore, we hypothesized that preserving vascular grafts with BCE alleviates vascular dysfunction in a rat model subjected to cold ischemia followed by a warm reperfusion IR injury.

Methods: Male Lewis rats (n = 9/group) were divided into three groups: control, IR, and IR + BCE. The aortic arches of the control group were harvested, prepared, and immediately mounted in organ bath chambers for functional analysis. The aortic arches from the IR and IR + BCE groups were stored for 1 hour either in saline or saline supplemented with 7% (vol/vol) BCE, respectively, before being transplanted into the abdominal aorta of the recipients. The implanted grafts were explanted 1 hour after transplantation, and ex vivo vascular function was assessed. Additionally, we determined gene expression analysis of the vascular grafts using microarrays.

Results: Impaired maximal relaxation (Rmax) to acetylcholine in the IR group compared with controls was ameliorated in the IR + BCE aortic rings (Rmax: Control: 92 ± 2%; IR: 21 ± 2%; IR + BCE: 44 ± 2%, p < 0.05), indicating an improvement in endothelial function. The rightward shift of the concentration–response curves to sodium nitroprusside, an endothelium-independent vasorelaxant, in the IR group compared with controls were shifted to the left after preservation of rings with BCE. The sensitivity to sodium nitroprusside, assessed by the pD2 value (the negative logarithm of the corresponding EC50), was as follows: Control: 8.02 ± 0.03; IR: 7.62 ± 0.07; IR+BCE: 8.13 ± 0.06, p < 0.05). In the IR group compared with controls, a total of 1,620 transcripts were significantly altered: 887 genes were upregulated and 733 genes were downregulated. In the IR + BCE aortas compared with IR group, only 44 genes were upregulated and 10 genes were downregulated.

Conclusion: Preserving arterial grafts with BCE alleviates endothelial dysfunction following in vivo IR injury in rats.

Publication History

Article published online:
11 February 2025