How Different Insulin Administration Routes Affect Hepatic Glycogen Levels after an Aerobic Exercise Bout in Male Rats with Type 1 Diabetes
Abstract
Type 1 diabetes mellitus (T1DM) is an autoimmune disease resulting in the destruction of pancreatic beta cells leading to deficient insulin production. Insulin plays a crucial role in regulating glucose metabolism, facilitating the utilization of dietary energy. Individuals with T1DM exhibit dysregulated blood glucose concentration and necessitate exogenous insulin administration. Intensive insulin therapy (IIT) is employed commonly, typically via subcutaneous (SQ) injections to treat individuals with T1DM. However, SQ insulin delivery fails to mimic endogenous insulin secretion, particularly its physiological distribution directly to the liver via the hepatic portal vein. Insulin concentration in the liver contributes significantly to glucose homeostasis, notably during aerobic bouts of exercise. Individuals with T1DM lack direct hepatic insulin exposure and exhibit depleted liver glycogen reserves. Lower liver glycogen results in a diminished ability to release glucose into the bloodstream, leading to greater susceptibility of exercise-induced hypoglycemia. This study examined an alternative route of insulin administration directly into the Omentum pouch (OP.). The OP is an anatomical structure located within the abdominal cavity, vascularly akin to the pancreas. This study aimed to evaluate the efficacy of OP insulin delivery in enhancing liver glycogen storage and mitigating post-aerobic exercise (AE) hypoglycemia. Contrary to expectations, OP insulin administration exhibited inferior glycemic control and impaired glycogen utilization compared to traditional SQ administration. This finding was attributed to abnormally increased insulin concentration in the hepatic portal vein.