Protamines are proteins derived from the sperm or testes of salmon or related fish. They are added [1] are added to insulins NPH Neutral Protamine Hagedorn and PZI protamine zinc to delay their absorption.
The difference between isophane/NPH insulins and PZI insulins is the amount of protamine used; there is more in PZI than in NPH/isophane insulins. It's the extra protamine which makes the PZI a slow-acting insulin.[2]
The basis of absorption of any insulins containing protamine [3] is the breakdown of this protein by proteolytic enzymes [4] or proteases in the body. Only after this is accomplished can the insulin itself be absorbed. More protamine in the suspension means insulin absorption will be delayed longer; less protamine means the insulin will act faster.
Protamine, like insulin itself, is a protein. In the case of antibody formation, it is possible that the insulin itself is not the cause of them; the proteins present in the suspension, such as protamine, may be. [5] In this case, changing the type of suspension would solve the problem.
Protamine has other medical uses as well.
See also suspension.
References[]
- ↑ The Diagnosis and Management of Anaphylaxis - Protamine. Journal Allergy & Clinical Immunology (1998).
- ↑ Greco, Deborah (2010). Treating Diabetes Mellitus in Dogs and Cats. Western Veterinary Conference.
- ↑ Williams, Robert (1968). Textbook of Endocrinology, 4th edition. W. B. Saunders.
- ↑ Proteolytic Enzymes. Wikipedia.
- ↑ Problems With Regulation of Diabetes Mellitus-Antibodies. Intervet.