<prompt> Which is the single most impoant factor that stimulates insulin secretion?Decreased plasma glucose concentration inhibits insulin releaseDecreased plasma glucose concentration stimulate insulin releaseIncreased plasma glucose concentration stimulates insulin releaseIncreased plasma glucose concentration inhibits insulin release  <response>: Increase glucose levels E.g.: after meals Glucose entry into pancreatic cells. Glucose undergoes glycolysis generate ATP. ATP - sensitive K channels inhibited, causing depolarization of the cell membrane. Voltage gated Ca channels open. Influx of Ca into the cell. Fusion of insulin containing vesicles with cell membrane. Insulin released by exocytosis. Factors and Conditions that increase or Decrease Insulin Secretion Increase Insulin Secretion Decrease Insulin Secretion Increased blood glucose Decreased blood glucose Increased blood free fatty acids Fasting Somatostatin Increased blood amino acids a- Adrenergic activity Gastrointestinal hormones gastrin, cholecytokinin, secretin, gastric inhibitory peptide Leptin Glucagon, growth hormone, coisol Parasympathetic stimulation; acetylcholine b- Adrenergic stimulation Insulin resistance; obesity Sulfonylurea drugs glyburide, tolbutamide 