Background

Obesity is in alarming high rate as well as a growing concern in the world.A novel hormone called meteorin,is a circulating factor that is induced in muscle after exercise and in adipose tissue upon cold exposure. Irisin is a exercise induced myokine released from the cleavage of FNDC-5.In this study we aimed to quantitatemeteorin and Irisin after surgery in plasma as well as BAT of DIO rat model.

Methods

Sprage Dowley male rats (4 weeks old) were divided in two groups:Control and Diet Induced Obesity (DIO). The control group (n=9) were fed ad libitum regular rat chow and water. The DIO group (n=14) were fed ad libitum “Cafeteria Diet”. DIO group were subdivided into 2 sub-groups at 21 weeks i.e SHAM(n=9) and Gastric Sleeve(GS)(n=5). Animals were fasted 12-15 hours prior to surgery/sampling. DIO animals undergone surgery were raised till week 25 for sampling of blood at different time point: baseline(T0) and 30 days post-operative(T30). At 30 days the animals were sacrificed,and tissues were collected. Meteorin and Irisin levels were measured by ELISA.

Results

Circulating meteorin was higher in DIO animals compared to controls. Meteorin was reduced after gastric sleeve from 1277.7±10.1pg/ml at T0 to 916.9±41.1pg/ml at T30 (P<0.05). Meteorin and irisin were assessed in Muscle and BAT of control, SHAM and gastric sleeve group. Both meteorin and irisin were higher in the muscle of rats that underwent gastric sleeve. Meteorin in control muscle was 73.3±9.8 pg/ml vs.99.3±6.6 pg/ml in GS. Irisin was 29.1±5.2 pg/ml in control muscle vs 46.4±6.2 pg/ml in GS. Unlike muscles,meteorin and irisin were reduced in the BAT after surgery. Meteorin was 15.7±3.4 pg/ml in control vs 14.4±2.1 pg/ml after surgery (P=0.046).Irisin was 3.2±1.2 pg/ml in control vs 1.8±0.4 pg/ml after surgery (P=0.04)

Conclusions

Our data show dichotomy in the expression level of meteorin and irisin in muscle and BAT. This needs further investigation about the role of these proteins and their impact on the browning of the tissues.