My Cell Bio book states that the smooth ER is involved in th

My Cell Bio book states that the smooth ER is involved in the breakdown of glycogen. The liver stores glucose as glycogen in granules associated with the smooth ER and is broken down into glucose-1-phosphate by phosphorolysis before being converted to glucose-6-phosphate.

I would like to know for individuals with diabetes, what is going on in the smooth ER and liver cells to result in not producing enough insulin or could it be that the person\'s body is breaking down too much glycogen/glucose? Is it both factors?

Solution

Insulin is not produced in liver cells. It is produced by beta cells of pancreas. Insuline is produced in response to high sugar level in blood which allows the glucose to be taken up by insulin dependant cells.

The brakedown of glycogen in liver cells is stimulated by glucagon a counterregulatory hormone that works against the action of insulin which is secreted by alpha cells of pancreas in response to very low blood sugar level. Glucagon causes the liver to convert stored glycogen into glucose, which is released into the bloodstream. Secretion of high level of glucagon can cause due to pancreatic tumor which results in more breakdown of glycogen in liver amd release of more glucose in bloodstram. The most common cause of hyperglucagonemia is an absence or deficiency of the restraining influence of insulin on glucagon production.

There are two types of diabetes.

Type 1 called insulin dependant diabetes results from lack of insulin by pancreatic beta cells. It may cause due to autoimmune disorder in which beta cells are destroyed by body\'s immune system. some individuals lose the ability to secrete glucagon in response to low blood sugar, making them especially prone to severe hypoglycemia. When people with diabetes are unconscious or too confused to consume a food or drink containing carbohydrate, an injection of glucagon can restore the blood glucose level to normal within 5 or 10 minutes.

Type 2 called insulin independant diabetes begins with glucose intolerence/ insuline resistance of body cells i.e, loss of normal tissue sensitivity to insulin. In an effort to maintain glucose homeostasis, increased amounts of insulin are secreted. However, as the need to augment insulin secretion continues, the beta cell may lose the ability to compensate, and frank hypoinsulinemia can supervene.