Title: Aprotinin
CAS Registry Number: 9087-70-1
CAS Name: Pancreatic basic trypsin inhibitor
Additional Names: pancreatic trypsin inhibitor (Kunitz)
Manufacturers' Codes: Bayer A 128; Riker 52G; RP-9921
Trademarks: Antagosan (HMR); Antikrein (Teikoku Zoki); Fosten (Serono); Iniprol (Sanofi Winthrop); Kir Richter (Lepetit); Repulson (Mochida); Trasylol (Bayer); Trazinin (Tobishi); Zymofren (Specia)
Molecular Formula: C284H432N84O79S7
Molecular Weight: 6511.44
Percent Composition: C 52.39%, H 6.69%, N 18.07%, O 19.41%, S 3.45%
Literature References: Serine protease inhibitor which inhibits kallikrein, plasmin, trypsin, chymotrypsin and various intracellular proteases. Single chain polypeptide containing 58 amino acids; found in tissues and blood, highest concentration in bovine parotid gland, pancreas and lung. Initial description: H. Kraut et al., Z. Physiol. Chem. 192, 1 (1930). Isoln from bovine pancreas: M. Kunitz, J. H. Northrup, J. Gen. Physiol. 19, 991 (1936); from bovine parotid glands: H. Kraut, R. Körbel, US 2890986 (1959 to Bayer). Amino acid sequence: B. Kassell et al., Biochem. Biophys. Res. Commun. 18, 255 (1965); F. A. Anderer, S. Hörnle, Z. Naturforsch. 20b, 457, 462 (1965); B. Kassell, M. Laskowski, Biochem. Biophys. Res. Commun. 20, 463 (1966). Two-dimensional 1H-NMR studies: K. Nagayama, K. Wüthrich, Eur. J. Biochem. 114, 365 (1981); G. Wagner et al., ibid. 375. Review of early literature: I. Trautschold et al., Biochem. Pharmacol. 16, 59-72 (1957). Review of mechanism of therapeutic action: G. Haberland, R. McConn, Fed. Proc. 38, 2760-2767 (1979). Review of use as a proteolytic inhibitor in radioimmunoassays of polypeptide hormones: E. S. Zyzner, Life Sci. 28, 1861-1866 (1981). Review of biochemistry and applications: H. Fritz, G. Wunderer, Arzneim.-Forsch. 33, 479-494 (1983); of pharmacology and therapeutic efficacy in reducing blood loss associated with cardiac surgery: R. Davis, R. Whittington, Drugs 49, 954-983 (1995).
Properties: uv max (pH 5.9): 280 nm. Isoelec pt pH 10.5. Stable in neutral or acid media at high temp. Irreversible changes in molecular structure occur in strongly alkaline media (pH >12). Partially and reversibly denatured on treatment with 8M urea. May be kept at room temp in physiological saline soln for >1 yr without detrimental effects. LD50 i.v. in mice: 2500000 kallikrein inhibitor units/kg (Trautschold).
Absorption maximum: uv max (pH 5.9): 280 nm
Toxicity data: LD50 i.v. in mice: 2500000 kallikrein inhibitor units/kg (Trautschold)
Use: Proteolytic inhibitor in radioimmunoassays of polypeptide hormones.
Therap-Cat: Protease inhibitor.
Keywords: Protease Inhibitor.
Aptiganel Apyrase Aquaporins Arabinose Arabitol

Systematic (IUPAC) name
Clinical data
AHFS/Drugs.com monograph
Pregnancy cat. X
Legal status RX/POM
Dependence liability None
Routes Intravenous
Pharmacokinetic data
Bioavailability 100% (intravenous)
CAS number 9087-70-1 YesY 9004-04-0
ATC code B02AB01
DrugBank DB06692
KEGG D02971 YesY
Synonyms Trasylol, bovine pancreatic trypsin inhibitor
Chemical data
Formula C284H432N84O79S7 
Mol. mass 6511.51 g/mol
 N (what is this?)  (verify)

The drug aprotinin (Trasylol, previously Bayer and now Nordic Group pharmaceuticals), is the small protein bovine pancreatic trypsin inhibitor, or BPTI, which inhibits trypsin and related proteolytic enzymes. Under the trade name Trasylol, aprotinin was used as a medication administered by injection to reduce bleeding during complex surgery, such as heart and liver surgery. Its main effect is the slowing down of fibrinolysis, the process that leads to the breakdown of blood clots. The aim in its use was to decrease the need for blood transfusions during surgery, as well as end-organ damage due to hypotension (low blood pressure) as a result of marked blood loss. The drug was temporarily withdrawn worldwide in 2007 after studies suggested that its use increased the risk of complications or death;[1] this was confirmed by follow-up studies. Trasylol sales were suspended in May 2008, except for very restricted research use. In February 2012 the European Medicines Agency (EMA) scientific committee reverted its previous standpoint regarding aprotinin, and has recommended that the suspension be lifted.[2] Nordic became distributor of aprotinin in 2012.[3]