Serum Lipocalin 2 Levels in Acute Exercised Prediabetic Rat Model in Comparison to Normal Healthy Control

Abstract

Background: Excess caloric intake expands adipose tissue resulting in a higher risk of metabolic disease. Lipocalin 2 (LCN2) is an adipokine having a role in innate immunity and energy metabolism. It is an acute phase protein that was recently correlated with potential effects on obesity and inflammation. The reaction of this protein to progressive exercise in animals has limited studies. Exercise encourages weight loss and improves insulin sympathy. However, the molecular mechanisms mediating its beneficial effects are not fully understood. Obesity associates with increased production of inflammatory cytokines, which in turn, subsidizes to systemic insulin resistance. LCN2 has been shown to have a significant association with body mass index (BMI). However, only few of the LCN2-related studies have investigated whether LCN2 constitutes a causal factor of the metabolic conditions in animals. One of the best strategies to prevent obesity and its associated inflammation is participation in regular physical activity. Objective: This study was designed to test the hypothesis that exercise mitigates this inflammatory response, thereby improving insulin sensitivity, we tested whether there is an insulin-sensitizing effect of exercise is associated with related changes in circulating LCN2 levels in rats. Design: A total number of 24 adult healthy male albino rats were used. Rats were divided into three groups: group I (control, C), group II (model of pre-diabetic obese rats without exercise, PD) and group III (model of pre-diabetic obese rats with acute voluntary exercise, PDE). Results: This study revealed that after a 2 days acute exercise program, insulin sensitivity was improved, as indicated by a significant decrease in serum insulin (1.98±0.04), serum glucose (121.75±2.85) and Homeostasis Model Assessment for Insulin Resistance Index (HOMA-IR) (0.59±0.02) in PDE in comparison to corresponding values in PD group (3.94±0.08), (159±1.49) and (1.44±0.11) respectively. Also, Serum LCN2 concentrations were significantly decreased (62.88±1.79) in PDE group in comparison to PD group (94.75±3.36). Conclusion: We concluded that exercise has an insulin sensitizing effect in the pre-diabetic stage and its mechanism could involve a reduction in LCN2 levels in exercise-trained group.