Effects of apelin on reproductive functions: relationship with feeding behavior and energy metabolism

Apelin is an adipose tissue derived peptidergic hormone. In this study, 40 male Sprague-Dawley rats were used (four groups; n = 10). Apelin-13 at three different dosages (1, 5 and 50 μg/kg) was given intraperitoneally while the control group received vehicle the same route for a period of 14 days. In results, apelin-13 caused significant decreases in serum testosterone, luteinizing hormone and follicle-stimulating hormone levels (p < 0.05). Administration of apelin-13 significantly increased body weights, food intake, serum low-density lipoprotein and total cholesterol levels (p < 0.05), but caused significant decreases in high-density lipoprotein levels (p < 0.05). Serum glucose and triglyceride levels were not significantly altered by apelin-13 administration. Significant decreases in both uncoupling protein (UCP)-1 levels in the white and brown adipose tissues and UCP-3 levels in the biceps muscle (p < 0.05) were noted. The findings of the study suggest that apelin-13 may not only lead to obesity by increasing body weight but also cause infertility by suppressing reproductive hormones.

Archives of physiology and biochemistry. 2016 Aug 05 [Epub ahead of print]

Suat Tekin, Yavuz Erden, Suleyman Sandal, Ebru Etem Onalan, Fatma Ozyalin, Hasan Ozen, Bayram Yilmaz

a Department of Physiology , Faculty of Medicine, Inonu University , Malatya , Turkey ., b Department of Molecular Biology and Genetics , Faculty of Science, Bartin University , Bartin , Turkey ., a Department of Physiology , Faculty of Medicine, Inonu University , Malatya , Turkey ., c Department of Medical Biology , Faculty of Medicine, Firat University , Elazig , Turkey ., d Department of Biochemistry , Faculty of Medicine, Inonu University , Malatya , Turkey ., e Department of Pathology , Faculty of Veterinary Medicine, Kafkas University , Kars , Turkey ., f Department of Physiology , Faculty of Medicine, Yeditepe University , Istanbul , Turkey.