Volume 20 | Issue 1 Article 1 1958 The aN ture and Applications of Tryptic Enzymes in Veterinary Practice Earl F. Huffman Follow this and additional works at: https://lib.dr.iastate.edu/iowastate_veterinarian Part of the Veterinary Toxicology and Pharmacology Commons Recommended Citation Huffman, Earl F. (1958) "The aN ture and Applications of Tryptic Enzymes in Veterinary Practice," Iowa State University Veterinarian: Vol. 20 : Iss. 1 , Article 1. Available at: https://lib.dr.iastate.edu/iowastate_veterinarian/vol20/iss1/1 This Article is brought to you for free and open access by the Journals at Iowa State University Digital Repository. It has been accepted for inclusion in Iowa State University Veterinarian by an authorized editor of Iowa State University Digital Repository. For more information, please contact [email protected]. The Nature And Applications Of TRYPTIC ENZYMES IN VETERINARY PRACTICE Earl F. Huffman, D.V.M. NZYMES, or ferments as they were glands of domestic animals (trypsin), or E known in earlier times, have been from the vegetable kingdom as in the case used in medicine for centuries. From the of papain. time of Pasteur interest in enzymes has Of the three major types papain is per­ increased till, at the present date, we have haps the most proteolytic of the group (1). active research groups devoting much However, it strongly attacks viable mam­ time and money to the study of the nature malian proteins and is difficult to control and applied uses of a great variety of unless very closely supervised in its ap­ enzymes. plication. For that reason papain has be­ . Most chemical reactions which occur in come restricted in routine use in medicine, living cells are accelerated by enzymes. The mammalian enzymes such as tryp­ Essentially, enzymes are biological cata­ sin and chymotrypsin have been intensely lysts and are protein in nature. Most en­ tested as debriding agents in wound treat­ zymes are water soluble. As they exist ments and found to be safe for routine use within the mammalian body, enzymes may (2, 3, 4, 5). One of the first crude uses of be surrounded by other proteins. They are trypsin was in the application of maggots thus completely liberated only when this to gangrenous wounds during World War protein is dissolved since they cannot dif­ 1. It has since been found that the blow fuse through it. Enzymes are amphoteric fly maggots elaborated a tryptic substance in character and, as such, act as electro­ which accomplished an efficient digestion lytes in various solutions (1). of necrotic material in wounds, especially Proteolytic enzymes, at the present time, infected type injuries. command the greatest interest in the field Recent studies (2, 3, 6, 7) in the field of medicine and surgery. The common of medicine and veterinary medicine have sources of these products are from certain indicated their value in conditions which streptococci (streptokinase), the pancreas would require radical surgical procedures Dr. Huffman received his degree from Michi­ to effect debridement of dirty wounds be­ gan State University in 1952. He is Manager, fore healing could be accomplished. Tryp­ Professional Relations, Armour Veterinary Lab­ oratories. sin has been used very effectively in the Issue 1, 1958 9 treatment of topical injuries and has also been suc~essfully used in intrathoracic applications (2, 8) to resolve the empyema associated with tuberculosis. TRYPSIN .AND ,ITS ACTIONS Trypsin is available to the veterinary profession in a purified, lyophilized crys­ talline form (9). This for;m (Tryptar­ Vet®, Armour Veterinary Laboratories) is the activated trypsin and is ready to function, when applied directly to moist wounds or applied by irrigatidns or wet packs to q.ry necrotic type lesiqns. It has been demonstrated both expe~imentally (2) and clinically (3,8) that the I£ollowing sequence of events occur when trypsin is applied to wounds. The necrotic material can be seen ito be­ come loosened and dissolved from the sub­ strate of the wound. Trypsin does not digest normal healthy tissue. Pathological leucocytes rapidly disappear from the wound and normal leucocytes enter into the area. Healthy regenerating tissue forms rapidly to accelerate healing. There is no side reaction whatsoever Dr. Earl F. Huffman attendant with trypsin usage in open, freely-draining wounds. In treating car­ uncle conditions, as in fistulous withers of 6, 7) and most recently in experimental the llorse, adequate drainage must be es­ animals that severely infected wounds or tablished. Tryptic digestion of tissue may cleanly induced surgical wounds (12) liberate histamine substances (6, 8, 10) treated with trypsin heal more rapidly which could be absorbed and cause a than similar wounds in control animals.' transient pyrexia and occasional stinging. Surgical excision of the nerves controlling In these. instances antihistamine adminis­ the blink reflex of rabbits resulted in re­ tered at usual dosages for the species will generation of the nerves on an average of counteract this effect. Upon repeated use 5 days earlier with trypsin treated animals of trypsin this phenomenon does not ap­ as opposed to controls. W oundhealing pear again. which occurs at the skin surface heals on The digestive action of trypsin breaks an average of 2 days earlier than controls. down proteins and partially hydr;olyzed Puncture wounds on test animals heal proteins at peptide linkages (1, 11). This much more rapidly the first 3 days follow­ results in liquefaction of necrotic tissue ing injury in trypsin treated cases than do without formation of ~ntermediate pro­ untreated controls or controls treated with ducts which may cause anaphylactic reac­ hydrocortisone. tions. In the human and. the animal, tryp­ Trypsin injected parenterally (2, 13, 14, sin does not cause production of antibodies 15) re,sults in a pronounced anti-inflam­ or any undesirable side reactions when' matory response being elicited in a variety applied topically or in body cavities where of pathological conditions where inflam­ aspiration may be accomplished or free mation is always present. However, it has drainage established.- been found that intravenous use of trypsin It has been demonstrated clinically (3, interferes with the anti-clotting mechan- 10 Iowa State College Veterinarian isms in the blood stream and such action otics to cont:rol the infection. may result in formation of intravascular It has been found in human cases (8) clots (16,17). This phenomenon will occur that the introduction of 500,000 units into in laboratory animals even in the absence the thoracic cavity of chronic tubercular of calcium ions. In many case studies (2, cases with empyema results in a rapid li­ 3, 6, 7, 8) trypsin has resulted in the cir­ quefaction of the empyema making pos­ cumvention of radical surgery 'and has sible easy aspiration and drainage of the effected permanent healing of many . affected pleura. Also, after a few treat­ chronic conditions which were refractive ments the tubercular organisms can no to the accepted means of therapy. longer be detected in the affected area. This has been adequately demonstrated Similar effects upon bacteria (2, 3) are by Johnson, et al., in the following com­ noted in many other infected type wounds. mon conditions. For fistulous withers in Following a few applications of trypsin horses (cases in which drainage has been the invading bacteria carinot be detected. established naturally or where surgical This is assumed to be due to the effect of . incision was required) approximately trypsin upon altering the substrate of the 400,000 units (Armour units, 1,000 units area of injury so that pathogenic bacteria = 1 mg. tryptic activity) 'Of t:rypsin daily can no longer secure nutrition from the for 7 days has induced normal repair site and, hence, die away. It has also been prosesses. shown that trypsin digests the capsular A solution of the enzyme may be inject­ material from many pathogenic micro­ ed into the area- or irrigated through the organisms. This must not be construed to fistulous tracts.. 'J:'he crystalline material mean that trypsin is antibiotic, but this may be blowrtinto the lesions with a pow­ feature combined with such agents en­ der blower, or it may be inserted in fistu­ hances the effect of antibiotic therapy in lous tracts by use of gelatin capsules. many conditions. Foot rot in cattle as with foot canker in Chronically infected sinuses in cattle horses has been satisfactorily resolved and horses have been cured through in­ through daily use of trypsin. Two-hundred troduction of trypsin solution into the si­ thousand to 400,000 units applied directly nus and allowing it to remain for about to the lesion or injected into the fistula is 24 hours, then tilting the head or estab­ sufficient for a daily treatment. Continued lishing surgical drainage to drain out the for a week or less, this therapy results in liquefied material. This resulted under normal healing of the condition. This has conditions where antibiotics or methods of in several instances circumvented ampu­ flushing the sinus hadyield~d poor results. tation of the claw to correct foot rot. In t:reatmentt of topical \:wounds, ab­ Trypsin may be injected directly into scesses and hematomas, the, amount' of pus-filled joint capsules, allowed to work trypsin to use depends upon \ the extent~ for a few hours, then aspirated, leaving the and nature of the injury. On \he whole, joint free of caseous or purulent material. small lesions, a few inches in area, would In cases of gangrenous and purulent not require more than 50,000 tq 100,000 mastitis, depending upon the size of the units of trypsin daily until resolution of infected area, 200,000 to 800,000 units of the condition is evident. Most of these trypsin· daily results in considerable re­ resolve after one to three applications of duction- of inflammation.