Short-term exercise training improves vascular function in hypercholesterolemic rabbit femoral artery

Area of Science:

• Cardiovascular Physiology
• Exercise Science
• Nutritional Biochemistry

Background:

• Chronic exercise improves vascular function in healthy and hypercholesterolemic states.
• Early-stage vascular dysfunction can be induced by high-cholesterol diets.
• The efficacy of short-term exercise interventions on diet-induced vascular changes requires investigation.

Purpose of the Study:

• To determine if short-term exercise training can counteract vascular dysfunction caused by a high-cholesterol diet.
• To investigate the effects of varying durations of high-cholesterol diet and exercise on vascular responses.
• To assess the impact on endothelial calcium signaling and vasorelaxation.

Main Methods:

• Male New Zealand White rabbits were fed a high-cholesterol diet (2% cholesterol) for 2, 4, or 6 weeks.
• Exercise groups underwent treadmill running concurrently with diet intervention.
• Femoral artery function, endothelial calcium signaling (fura 2-AM), and vasorelaxation were assessed.
• Oil red O staining evaluated lipid deposition and fatty streak formation.

Main Results:

• High-cholesterol diet for ≥4 weeks induced lipid deposition, impaired acetylcholine-evoked calcium signaling, and reduced vascular responses.
• Vasorelaxation capacity decreased relative to endothelial intracellular calcium levels in hypercholesterolemia.
• Concomitant exercise training reversed these diet-induced adverse effects on vascular structure and function.

Conclusions:

• High-cholesterol diet, even for 4 weeks, causes vascular structural changes and impairs endothelial function in rabbit femoral arteries.
• Short-term exercise training, when performed in parallel with diet intervention (up to 6 weeks), completely prevents these detrimental vascular effects.
• This highlights the potential of timely exercise interventions to mitigate early-stage diet-induced vascular damage.