Abstracto

Oxytocin supplementation alleviates age-related insulin resistance through down regulation of pro-inflammatory cytokine gene expression

Abood AM, Alghamdi BS

Insulin resistance has long been recognized as a characteristic of aging. Many studies reported a beneficial role of oxytocin in obesity and type 2 diabetes. The aim of this study is to investigate the role of oxytocin in age-related insulin resistance in Wistar rats. Forty male rats were divided into four equal groups: young group, oxytocin-treated young group, old group and oxytocin treated old group. Oxytocin treated groups received Intraperitoneal (Ip) injection of oxytocin in a dose of 3 mg/kg body weight for 5 days. Experimental procedures included measurement of body weight, Body Mass Index (BMI) and intraperitoneal glucose tolerance tests. HOMA-IR index was also calculated. Assays of serum triglycerides, total cholesterol, LDL-C and HDL-C as well as serum IL-1β, IL-6 and TNF-α were performed. Malondialdehyde (MDA) and mRNA of IL-6, TNF-α and IL-1β were measured in Soleus Muscle (SM) and EF homogenates. Compared to young rats, old rats exhibited significant increase in BMI and HOMA-IR as well as an abnormal glucose tolerance test. Serum triglycerides, IL-6 and TNF-α were significantly increased in old rats. Furthermore, the MDA and mRNA of TNF-α and IL-6 of both SM and EF homogenates were significantly higher in old rats compared to young controls. These results, however, were notably lower in oxytocin supplemented rats compared to non-treated age matched group. In conclusion, oxytocin improves age related insulin resistance by alleviating inflammation and oxidative status in insulin sensitive tissues without affecting body weight.