Unveiling the effects of exercise and protein diet on pancreatic structure in ovariectomized aged rats

Objective: Evaluate structural alterations of the pancreas in ovariectomized elderly female rats that ingested different animal or vegetable protein sources and who underwent moderate resistance exercise. Methods: Female Wistar rats were divided into eight experimental groups: sedentary and non-ovariectomized animals plus vegetable protein diet (CVS) or animal protein diet (CAS); trained and non-ovariectomized rats plus vegetable protein diet (CVT) or animal protein diet (CAT); sedentary and ovariectomized groups plus vegetable protein diet (VOS) or animal protein diet (AOS); trained and ovariectomized animals plus vegetable protein diet (VOT) or animal protein diet (AOT). Results: Our results showed a decrease in pancreatic islet area in sedentary groups submitted to ovariectomy. On the other hand, we observed an increased frequency of minor and medium pancreatic islets in vegetable and animal diets, respectively. Additionally, all groups had a significant difference in volume density of acini, ducts, blood vessels, and pancreatic islets. Finally, immunohistochemistry demonstrated a decrease of glucagon in sedentary ovariectomized groups and a decrease of insulin in ovariectomized groups submitted to resistance training. Conclusion: Both resistance training and dietary intake contributed to pancreatic modifications in estrogen-deprived groups. Accordingly, further studies are needed regarding the structural and functional properties involving both interventions and menopause for a better understanding of our results.