Effects of regular swimming exercise on caveolin, insulin signaling, and SREBP-1c in adipose tissue of high-fat-fed ovariectomized rats.

PURPOSE: This study examined whether regular exercise modulates subcutaneous adipose tissue expression of caveolae-related genes (Cav-1, Cav-2, and Cav-3), insulin signaling mediators (IR, IRS-1, and IRS-2), and sterol regulatory element-binding protein-1c (SREBP-1c) in ovariectomized (OVX) rats.

METHODS

Thirty-week-old female Sprague-Dawley rats were ovariectomized and assigned to general diet (OVX-GD), high-fat diet (OVX-H), or high-fat diet plus exercise (OVX-H+EX) groups (n = 7). Swimming exercise performed for 60 min/day, 5 days/week for 8 weeks. After 12-h fast, inguinal adipose tissue was collected and mRNA expression was analyzed by semi-quantitative RT-PCR. Data were analyzed using one-way ANOVA with Tukey's post hoc test (p < 0.05).

RESULTS

High-fat feeding increased body weight and fat mass compared with the OVX-GD group. Despite no reduction in food intake, exercise attenuated weight gain and reduced final body weight and fat mass (p < 0.05). OVX-H rats showed increased Cav-1, Cav-2, and SREBP-1c expression and decreased IR and IRS-1 expression. Exercise reversed these changes. IRS-2 expression was also significantly increased in the exercise group (p < 0.05), whereas Cav-3 expression did not differ among the groups.

CONCLUSION

Regular exercise may improve adipose tissue metabolic regulation in OVX rats by modulating the mRNA expression of caveolae related genes and suppressing lipogenic gene activity.