Insulin β cells secrete insulin, which is regulated by the concentration of nutrients in the plasma, especially glucose. But this is not to say that the higher the blood sugar, the more it can stimulate the islet β-cells to secrete insulin. This effect is only in the range of physiological concentration. The physiological concentration of glucose in plasma can not only stimulate β cells to secrete insulin, but also promote β cells to synthesize insulin.

However, if the blood sugar is too high and lasts for a long time, there will be a sugar poisoning state, which will lead to acute failure of β cell function. Stop insulin secretion, if this high-sugar stimulation can be released as soon as possible, β-cell function can return to normal. If the continuous high glucose stimulation time is too long, the β cells will undergo vacuolation, atrophy and even apoptosis, causing permanent damage to the islet function. Stimulate β-cells to secrete more insulin, this effect is only in the range of physiological concentration.