Final answer:
Insulin release is not stimulated by low blood glucose levels, fasting, or counter-regulatory hormones but is primarily triggered by a rise in blood glucose levels, food intake, and certain hormones.
Step-by-step explanation:
Insulin release is not stimulated by conditions such as fasting, exercise when blood glucose levels may drop, or by counter-regulatory hormones like glucagon, epinephrine, cortisol, or growth hormone. These situations typically trigger mechanisms to raise blood glucose levels, not lower them.
While the primary stimulus for insulin secretion is an increase in blood glucose levels, certain other factors such as ingestion of food, particularly carbohydrates, incretin hormones, and parasympathetic neural signals can also promote insulin release. However, in the context of diabetes mellitus, particularly in diabetes mellitus patients who are insulin non-responsive, insulin therapy may not result in a significant decrease in blood glucose. This resistance can be due to various reasons like defective insulin receptors, the presence of insulin antibodies, or an excess of insulin antagonists.