Insulin and form fibrillar interdigitated beta-sheets. This can cause injection amyloidosis, and prevents the storage of insulin for long periods. Insulin is produced in the pancreas and the Brockmann body (in some fish), and released when any of several stimuli are detected. These stimuli include ingested protein and glucose in the blood produced from digested food. Carbohydrates can be polymers of simple sugars or the simple sugars themselves. If the carbohydrates include glucose, then that glucose will be absorbed into the bloodstream and blood glucose level will begin to rise. In target cells, insulin initiates a signal transduction, which has the
Insulin receptor The main activity of activation of the insulin receptor is inducing glucose uptake. For this reason "insulin insensitivity", or a decrease in insulin receptor signaling, leads to diabetes mellitus type 2 – the cells are unable to take up glucose, and the result is hyperglycemia (an increase in circulating glucose), and all the sequelae that result from diabetes. Patients with insulin resistance may display acanthosis nigricans. A few patients with homozygous mutations in the "INSR" gene have been described, which causes Donohue syndrome or Leprechaunism. This autosomal recessive disorder results in a totally non-functional insulin receptor. These patients have low-set,