Role of Adenosine Receptor Agonist in a Rat Model of Diabetic-Induced Osteoporosis

Abstract Background Diabetic osteoporosis is caused by chronic hyperglycemia, oxidative stress, advanced glycation end products accumulation and microvascular changes. All these alter signaling pathways involved in bone metabolism. Adenosine receptors (ARs) are expressed in the bone and might play a role in bone homeostasis. Recent data reveal that A2AAR plays a key role in bone homeostasis and regeneration. However, whether it has a role in treatment of osteoporosis induced by diabetes has not been reported. Objective The aim of the present study was to evaluate the effect of CGS-21680, an A2A adenosine receptor agonist, in ameliorating osteoporosis induced by diabetes in a rat model. Materials and Methods Forty adult male Albino-rats were allocated into four groups: Group I: control group; Group II: untreated diabetic induced osteoporosis group; Group III: insulin treated diabetic-induced osteoporosis group; Group IV: adenosine receptor agonist treated diabetic-induced osteoporosis group. Diabetes was induced by a single intraperitoneal injection of STZ at a dose of 40 mg/Kg body weight. At the end of the study the bone marker osteocalcin, serum glucose, insulin, tumor necrosis factor-α, malondialdehyde, glutathione peroxidase, calcium and phosphorus were measured, and bone histopathological analysis was done. Results Compared with the untreated diabetic groups, the A2A adenosine receptor agonist treated group showed less bone loss, which was revealed by the increased cortical bone thickness and trabecular thickness. In addition to decreased oxidative damage and inflammation. Conclusion The decreased oxidative stress and inflammation in the A2A adenosine receptor agonist treated group supports a beneficial effect of A2AAR stimulation in treatment of diabetic induced osteoporosis, which was demonstrated by the improvement in bone microarchitecture.