Invastigation of relationship between plasma ghrelin levels and muscle atrophy in experimental diabetic rats

Aim:In this study, it was aimed to investigate the relationship between plasma ghrelin levels and muscle atrophy in an experimental diabetic rat model. Material and Method:56 male Wistar albino rats aged 8-10 weeks were used. Rats were divided into 8 groups, including four diabetic and four controls. Experimental groups, DD-1: one-week diabetes (n=7), NDK-1: one-week control (n=7), DD-2: three-week diabetes (n=7), NDK-2: three-week control ( n=7), DD-3: diabetes at six weeks (n=7), NDK-3: control at six weeks (n=7), DD-4: diabetes at eight weeks (n=7), NDK-4: at eight weeks control is such that (n=7). To induce diabetes a single dose of 45mg/kg intraperitoneal streptozotocin was injected into rats. At the end of the specified weeks, body weights and fasting blood glucose levels were measured. Plasma ghrelin, muscle mTOR and myostatin values were measured by the ELISA method. The right gastrocnemius muscle was removed and weighed, and muscle histopathological images were examined. Results: It was determined that the gastrocnemius weights of the DD-2, DD-3, DD-4 groups decreased significantly compared to their own controls. Muscle cross- sectional area was signicantly decreased in DD-3 and DD-4 groups compared to controls (p<0,01). Muscle mTOR levels were found to be significantly lower in all diabetic groups compared to controls (p<0,01). Although muscle miyostatin levels were higher in diabetic groups, this increase was only significant in the DD-4 group (p<0,01). Plasma ghrelin levels were significantly lower in all diabetic groups compared to controls (p<0,01). A positive correlation was determined between plasma ghrelin levels and rat final weights, muscle cross-sectional area, gastrocnemius weights and mTOR levels. Conclusion: It was observed that muscle atrophy developed in diabetic rats over time. A significant positive correlation was found between plasma ghrelin levels and body weight, muscle weight, cross-sectional size of muscle fiber and muscle MTOR levels. Our results showed that there is a relationship between muscle atrophy seen in diabetes and plasma ghrelin level. Key words: Diabetes, mTOR, muscle, atrophy, ghrelin