Adiponectin directly improves endothelial dysfunction in obese rats through the AMPK-eNOS Pathway

Area of Science:

• Cardiovascular Research
• Endocrinology
• Molecular Biology

Background:

• Hypoadiponectinemia is linked to endothelial dysfunction and cardiovascular disease risk.
• Obesity induced by high-fat diets exacerbates endothelial dysfunction.

Purpose of the Study:

• To investigate adiponectin's effect on endothelial dysfunction in high-fat diet-induced obese rats.
• To elucidate the underlying mechanisms of adiponectin's action on the aorta.

Main Methods:

• Male Sprague-Dawley rats were fed high-fat or regular diets for 6 weeks.
• Isolated rat aortic segments and human aortic endothelial cells were treated with globular adiponectin (gAD).
• Endothelial function, nitric oxide (NO) production, and protein phosphorylation (eNOS, AMPK, Akt) were assessed.

Main Results:

• High-fat diet induced severe endothelial dysfunction in rat aortas.
• gAD partially improved endothelium-dependent relaxation and increased NO production.
• gAD enhanced endothelial nitric oxide synthase (eNOS) activity via AMPK phosphorylation in endothelial cells.

Conclusions:

• Adiponectin reverses diet-induced endothelial dysfunction.
• Adiponectin increases NO production by phosphorylating eNOS and reduces NO inactivation.
• This suggests a novel therapeutic strategy for preventing vascular injury in obesity.