Vitamin A regulates obesity in WNIN/Ob obese rat; independent of stearoyl-CoA desaturase-1

Stearoyl-CoA desaturase 1 (SCD1), an important enzyme involved in monounsaturated fatty acid biosynthesis is a key player in energy homeostasis. Here, we tested the impact of vitamin A on hepatic and adipose tissue SCD1 expression and adiposity per se, using an obese mutant rat strain namely, WNIN/Ob developed at National Center for Laboratory Animal Sciences of National Institute of Nutrition, India. Seven months-old 24 male lean and obese rats of WNIN/Ob strain were divided into two groups; each group was subdivided into two subgroups having 6 lean and 6 obese rats and received diets containing either 2.6mg or 129mg vitamin A/kg diet for two months. Feeding of high (but non-toxic) doses of vitamin A resulted in significant reduction in body weight gain, and retroperitoneal white adipose tissue weight (RPWAT) in obese rats. Further, vitamin A feeding resulted in augmented expression of SCD1 in liver and RPWAT of lean rats, while no such effect was seen in obese rats. Taken together, the present data suggest that vitamin A decreases body weight gain in obese rat model independent of SCD1 gene regulation.