Final answer:
In type 1 diabetes, the imbalance caused by the absence of insulin elevates the role of glucagon in raising blood glucose levels. Glucagon stimulates glycogenolysis and gluconeogenesis, but without insulin, this action is unchecked, leading to high blood sugar.
Step-by-step explanation:
Glucagon's Role in Type 1 Diabetes
In individuals with type 1 diabetes, the body's immune system attacks and destroys the insulin-producing beta cells in the pancreas. As a result, glucagon, a hormone produced by the alpha cells, plays a crucial role in maintaining blood glucose levels when they fall too low. Normally, glucagon counters the action of insulin by stimulating glycogenolysis (the breakdown of glycogen to glucose) in the liver, and gluconeogenesis (the synthesis of glucose from non-carbohydrate sources), especially during periods of fasting or heavy exercise. However, in those with type 1 diabetes, the lack of insulin causes an imbalance, as glucagon continuously promotes the increase of blood glucose levels.
Since insulin normally counteracts the effects of glucagon, without sufficient insulin, the hyperglycemic effect of glucagon is exaggerated, leading to higher than normal blood sugar levels. This can be further complicated by target cell resistance to insulin, often contributing to the symptoms of diabetes mellitus. Additionally, hyperglucagonism can occur, which antagonizes the limited insulin action that might be present in type 1 diabetes, worsening hyperglycemia.
Rising blood glucose levels typically inhibit further release of glucagon through a negative feedback mechanism, intended to keep glucose levels stable. However, due to the insufficient insulin production in type 1 diabetes, this negative feedback is disrupted, leading to unopposed glucagon action and continuous elevation of glucose levels in the blood.