Pleiotropic effects of simvastatin in physically trained ovariectomized rats

Area of Science:

• Cardiovascular Physiology
• Autonomic Nervous System
• Pharmacology
• Oxidative Stress Research

Background:

• Ovariectomy in rats leads to detrimental cardiovascular and autonomic changes.
• Simvastatin is a statin drug with potential pleiotropic effects beyond lipid lowering.
• Physical training can mitigate some negative effects of ovariectomy.

Purpose of the Study:

• To investigate the effects of simvastatin on cardiovascular and autonomic functions in trained and untrained ovariectomized rats.
• To assess simvastatin's impact on membrane lipoperoxidation (oxidative stress) in these models.
• To determine if physical training potentiates simvastatin's effects.

Main Methods:

• Ovariectomized rats were divided into sedentary, sedentary+simvastatin, and trained+simvastatin groups.
• Exercise training was conducted on a treadmill; simvastatin was administered orally.
• Measurements included blood pressure, baroreflex sensitivity, cardiac autonomic function (vagal and sympathetic), and tissue lipoperoxidation.

Main Results:

• Simvastatin treatment reduced body weight and mean blood pressure in both sedentary and trained groups.
• Trained rats exhibited lower blood pressure and heart rate overall.
• Simvastatin enhanced baroreflex sensitivity, increased vagal effect (especially in trained rats), decreased sympathetic effect (in sedentary rats), and significantly reduced hepatic lipoperoxidation.

Conclusions:

• Simvastatin improves cardiovascular and autonomic functions and reduces oxidative stress in ovariectomized rats.
• The beneficial effects of simvastatin on these parameters are amplified by concurrent physical training.
• Cardiac lipoperoxidation is inversely related to vagal tone and directly related to sympathetic tone.