Pengaruh Frekuensi Stres Fisik terhadap Kadar Leptin Serum Tikus Wistar (Rattus novergicus) Betina dengan Diet Atherogenik

Abstract

Introduction: Leptin is a protein hormone produced by adipose tissue which plays important role in the regulation of energy metabolism and food intake. Atherogenic diets have been shown to cause hyperlipidemia, obesity and increased body fat reserves. Some studies suggested physical exercise were able to increase levels of serum leptin and improved leptin sensitivity. However other studies has also suggested that excessive physical exercise induced leptin resistance and changed the central control of energy balance in the central nervous system. Therefore, studies to evaluate the role of frequency of physical stress in levels of serum leptin is unknown.

Methods: Female wistar rats were divided into 6 groups (KN, KP, KPP, KSK, KDH and KSH). KN were given standard diet, while KP were given atherogenic diet for 10 weeks. Treatment groups were subjected to 5 minutes of forced swimming at intervals of twice weekly (KSK), once every two days (KDH) and daily (KSH) for 4 weeks after 6 weeks of atherogenic diet every. A pre-treatment group (KPP) were given atherogenic diet for 6 weeks as pretreathment baseline levels. At the end of treathment, rats were sacrified, serum were collected and leptin levels were examined using ELISA. All results were analyzed using One Way ANOVA and p is set at 0.05.

Result: Atherogenic diet did not significantly affect levels of serum leptin (p>0.05). Various frequency of physical stress shows significant difference between KSK (4.91 + 0.60) vs KDH (3.95 + 0.20). Correlation analyses showed weak negative correlation between levels of leptin serum and end of treatment body weight. However, no correlation were found between levels of leptin serum and dietary intake.

Conclusion: Twice weekly physical stress is considered as the most effective intervals to increased levels of serum leptin and modifying body weight in female rats fed with atherogenic diet.

Keywords: Atherogenic diet, frequency of physical stress, Serum Leptin