It is believed that many doctors who are new to clinical practice tend to confuse the name of insulin and its usage. Today, we will teach you how to remember the usage of insulin by combining the structure of insulin. The insulin molecular crystal consists of six insulin molecules and two Zn ions to form a hexamer of zinc-containing insulin. The hexamer is the storage form of insulin in B cells, but insulin is absorbed in the form of monomers, so for insulin to work, the hexamer must be depolymerized into a monomer in order to play its glucose-lowering role, and it is easy to understand the role of different time-acting insulins by understanding this. 1. Short-acting insulins mainly include lysergic insulin (trade name: Utro) and menthol insulin (trade name: Novolac). Among them, lysergic insulin is formed by replacing human insulin B28 proline with negatively charged lysine, while mentholatum insulin is formed by replacing human insulin B28 proline with aspartic acid. The reason why they can play hypoglycemic effect in a short time is because the change of structure makes the charge repulsion, which hinders the self-polymerization among insulin monomers, and in solution its mainly exists in the form of mixture of monomers and diomers, and monomers are the structure of insulin action, so the action time is fast. 2.Short-acting insulin is also called regular insulin or neutral insulin injection (animal-derived insulin), recombinant human insulin injection (Gansulin R, Novolin R, Eugenol R), where R is the meaning of regular. The basic structure of regular soluble human insulin is hexamer, and it can be absorbed only after dissociation into dimer and monomer after subcutaneous injection, and because it has to dissociate into dimer and monomer slowly after injection, it prolongs the onset of action time when soluble insulin is given subcutaneously, so it should be injected 30 minutes before meal. In the future, when you see the sign with “R” behind the insulin, remember to inject 30 minutes before meals. 3, medium-acting insulin (NPH) mainly includes low-refined protein zinc insulin and insulin zinc suspension, commonly used in the market are low-refined protein recombinant human insulin injection (Gansulin N); neutral low-refined protein zinc human insulin (Novolin N) The structure of medium-acting insulin is that several hexamers are brought together by fisetin, so that it takes longer time to depolymerize into monomers, thus prolonging the action time of insulin. 4. Long-acting insulins mainly include glargine insulin (trade name: Lactacell) and detergent insulin (trade name: Norplant). The isoelectric point of insulin is changed through the change of amino acid, from the original 5.14 to 6.17. When it is injected into body fluid with pH 7.14, it will precipitate, and the presence of zinc in the preparation can increase the stability of insulin hexamer, and the time of hexamer decomposition is prolonged, resulting in delayed absorption and prolonged, slow and smooth release. The absorption and diffusion of insulin is slow after subcutaneous injection. 98%-99% of insulin is bound to albumin in plasma and released into blood at an extremely slow rate, with a significantly longer half-life of about 14 hours and a stable plasma concentration with a small peak and trough curve. 5, premixed insulin refers to the mixing of short-acting insulin preparations and medium-acting insulin preparations in different proportions, which has the effects of both short-acting insulin and long-acting insulin. We often see insulin with numbers is premixed insulin, where the number is the proportion of short-acting or ultra-short-acting insulin.