Corticosteroids are used for all types of protamine reactions. Protamine is used in insulin aspart protamine and NPH insulin. NPH is an abbreviation for "neutral protamine Hagedorn". P1 forms disulfide bonds with the cysteine from the carboxy-terminal of another protamine P1. Other relatively common causes include chemotherapy, vaccines, protamine and herbal preparations. Its use has been supplanted by protamine sulfate. The structure of the sperm head is also related to protamine levels. No liver damage was found when the rats were treated with protamine. Human and chimp protamine has undergone rapid evolution. Recently, one efficient method for precipitating out RuBisCO involves the usage of protamine sulfate solution. Synthetic 'human' insulin is also complexed with protamine to form NPH. Protamine works by binding with heparin. Protamine and protamine-like (PL) proteins are among the sperm specific nuclear basic proteins (SNBPs). Protamine insulin was first created in 1936 and NPH insulin in 1946. Protamine sulfate will reverse Tinzaparin by 85% per package insert.