Effect of obestatin on pituitary gonadal axis, leptin and MDA levels in type 2 diabetic Sprague Dawley Rats

Abstract

Objective: To demonstrate the effect of Obestatin supplementation on oxidative stress and serum levels of testosterone, follicular stimulating hormone, luteinizing hormone and leptin in type 2 diabetic rats.

Study Design: Laboratory-based experimental study

Place and Duration of Study: Physiology Department, Army Medical College Rawalpindi from Mar-June 2015.

Methodology: Forty-five healthy male Sprague Dawley rats were randomly divided into three groups. Group-I (healthy rats) were fed with regular pellet diet (NPD). Group-II (diabetic rats) and group-III (Obestatin treated diabetic rats) were fed with high-fat diet (HFD) followed by a single IP injection of Streptozotocin in the dose of 35 mg/kg on 15th day. After ten weeks, group-III was treated with intraperitoneal Obestatin (1 nmol/100ml). Blood samples were obtained by terminal intra-cardiac sampling for bioassays of Insulin, testosterone, FSH, LH, MDA and leptin by ELISA.

Results: Obestatin supplementation in diabetic rats resulted in significant increase in FSH (9.4 ± 0.74 ng/dL), LH (3.89 ± 0.10 ng/dL) and testosterone levels (2.01 ± 0.09 ng/dL) in comparison with non-treated diabetic rats (7.04 ± 0.50 ng/dL), (1.70 ± 0.28 ng/dL) and (1.10 ± 0.40 ng/dL) respectively. Whereas leptin (3.91 ± 0.24 ng/dL) and MDA levels (1.75 ± 0.22 ng/dL) were reduced significantly when compared to the healthy rats (6.10 ± 1.29 ng/dL) and (1.96 ± 0.07 ng/dL) respectively.

Conclusion: Testosterone levels are increased by Obestatin supplementation in type 2 diabetic rats by stimulating the pituitary-gonadal axis due to a decrease in circulating leptin levels and oxidative stress.