Endothelium-derived relaxing factor-mediated vasodilation in mouse mesenteric vascular beds

Area of Science:

• Vascular Biology
• Endothelial Function
• Physiology

Background:

• The endothelium regulates vascular tone, primarily via endothelium-derived hyperpolarizing factor (EDHF) in rats.
• The role of the endothelium in mouse resistance arteries remains less understood.

Purpose of the Study:

• To investigate the mechanisms by which the endothelium in mouse mesenteric arteries regulates vascular tone.
• To compare endothelial regulation in mouse mesenteric arteries with that in rat mesenteric arteries.

Main Methods:

• Isolated mesenteric vascular beds from male C57BL/6 mice were perfused.
• Vascular responses to acetylcholine, A23187, and sodium nitroprusside (SNP) were measured.
• The effects of inhibitors (NOS, cyclooxygenase, K(+)-channel, gap-junction) on vasodilation were assessed.

Main Results:

• Acetylcholine and A23187 induced concentration-dependent vasodilation, abolished by endothelium dysfunction.
• Vasodilation to acetylcholine and A23187 was inhibited by nitric oxide synthase and K(+)-channel inhibitors.
• Prostanoids contributed to A23187-induced vasodilation, while gap-junctions mediated acetylcholine-induced vasodilation.

Conclusions:

• The endothelium in mouse mesenteric arteries regulates vascular tone through a combination of prostanoids, EDHF, and nitric oxide.
• These findings indicate a distinct endothelial regulatory system in mouse mesenteric arteries compared to rats.