Volume 20 | Issue 1 Article 1

1958 The aN ture and Applications of Tryptic Enzymes in Veterinary Practice Earl F. Huffman

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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. The trypsin so­ t:rypsin. On more extensive areas,· as one lution may be introduced into the affected might encoUnter in burns or where much quarter either by way of the teat canal or, loss of. tissue has occured with acute in­ if this is impossible, injected with a hypo­ fection and necrosis, several million units dermic needle directly into the affected inaybe required to complete the course area~ In the case of gangrenous mastitis, of treatment. an incision in the area may bE;! required to Effective dosage will come with experi­ ~drain the liquefied material. This therapy ence and usage of the product. As has been must be carried out with indicated antibi- indicated previously, one can observe

Issue 1, 1958 11 (over a 30-minute period of time) the ra­ take place. At present this product does pid digestive action of trypsin upon ne­ not appear to be as effective as other anti­ crotic tissue. This may serve as an index inflammatory agents for skin conditions. for future cases and provide a guide for Gillispie (22), reporting upon 141 cases the duration of treatment necessary. of all types in small animals, found that, as Trypsin must be considered as an ad­ an anti-inflammatory agent, chymotrypsin junct in treatment of dirty, infected and was of definite benefit in as many as 75 to necrotic wounds. Surgical debridement 85 per cent of the common conditions for could result in greater loss of body sub­ which it was used. The application of the stance and perhaps failure to remove some product to the running horse (2) has re­ of the foci of necrosis which may be deep­ sulted in dramatic effects upon rate of er than is possible to reach. It is easy to see healing and resolves trauma-induced in­ that removal of causes which impede heal­ juries in a much more rapid period of ing and which can be accomplished by time than had previously been experi­ enzymatic debridement is often to be enced. preferred to more radical approaches. The enzyme may be used prophylactic­ ally as well as therapeutically in all con­ CHYMOTRYPSIN ditions in which inflammation and edema retard healing or present a danger to the Chymotrypsin, an analogue of trypsin, involved organ. The dosage range which is commercially produced from beef pan­ has been employed in small animals is as creas glands. Its local action upon protein follows: cats and dogs up to 10 lbs., % cc. tissue is similar to that of trypsin (1, 18). intramuscularly every 12 hours; dogs 10 Chymotrypsin as a purified crystalline to 50 Ibs., 1f2 cc. every 12 hours; dogs over material will soon be available to veterin­ 50 Ibs., % to 1 cc. every 12 hours. In case arians for small animal use (Kymar®, Ar­ of severe inflammatory reaction, as in mour Veterinary Laboratories' oil sus­ massive trauma, these doses may be given pension of pure crystalline chymotrypsin). every 8 hours to effect. In large animals However, the use of this material in hu­ doses of 3 to 5 cc. daily result in similar man and veterinary medicine is not for effects. topical application. Some specific conditions in which chy­ Chymotrypsin may be safely injected motrypsin is effective in controlling the inflammatory processes and the resultant parenterally (intramuscularly) in oil or pain are as follows: aqueous suspensions. It does not interfere with the clotting mechanisms of the blood 1. Accident or non-surgical trauma as and possesses remarkable anti-inflamma­ bone fractures, lacerations, contusions. tory actions (2, 15, 18, 19, 20, 21). As op­ 2. Surgical trauma as mammary tumor posed to many anti-inflammatory products excision, perineal hernia correction, open on the market, this enzyme does not have reduction of bone fractures, abdominal any effect upon the endocrine system of surgery. the body. Its mode of action is at present 3. Inflammation of the eye and eyelids unproved. It does appear to have a selec­ as iritis, iridocyclitis, keratitis, conjunc­ tive activity which takes place at sites of tivitis, post-operative panophthalmitis. inflammation and reduces the edema, pain, 4. Myositis. and swelling, regardless of cause. 5. Cellulitis. The products may be used prophylactic­ 6. Abscesses. ally in preventing inflammatory condi­ Chymotrypsin hastens the absorption of tions. This has been effective in preventing hematomas, post-operative blood clots in inflammation which follows surgical oper­ the anterior chamber of the eye and hy­ ations such as intestinal surgery, eye sur­ popyon. gery, fracture repair, etc. Given prior to By reducing inflammation and edema, such surgical procedures, the edema is circulation is restored which in turn held down and rapid healing allowed to hastens absorption and halts tissue necro-

12 Iowa State College Veterinarian sis with an end result of enhanced healing 6. Johnson, E. L. Recent advances in equine with a minimum of pain. surgery. Paper presented at the second an­ nual Stud Manager's Course. Lexington, The enzyme is non-toxic and has no un­ Kentucky. November, 1952. toward side effects. It may be used simul­ 7. Mills, A. M. Newer treatments employed in taneously with other therapeutic agents cattle practice. Veterinary Medicine. 49:57- without interference. 60. 1954. 8. Reiser, H. G., Roettig, L. C., and Curtis, G. M. The tryptic debridement of fibrinopuru­ SUMMARY lent empyema. Surgical Forum (American College of Surgeons). W. B. Saunders Co. Purified crystalline trypsin is being Philadelphia. 1951. widely used in medicine and in veterinary 9. Northrop, J. H. and Kunitz, M. Crystalline medicine as a substitute for the scalpel in trypsin. 1. Isolation and tests of purity. Jour­ debriding wounds and for the liquefaction nal of General Physiology. 16:267-294. 1932. of caseous and purulent exudates in ab­ 10. Wells, J. A., Morris, H. C., and Dragstedt, C. A Significance of histamine in trypsin shock scesses and in body cavities. The enzyme is as determined by benadryl. Proceedings So­ safe in topical usage and has only occa­ ciety of Experimental Biology and Medicine. sional mild side effects if excessively used 62:209-213. 1946. in body cavities. 11. Kiihne, W. Digestion of protein by pancre­ atic j ;-::? Virchows Archives of Pathology Trypsin accomplishes effective debride­ and !ator.::.'. 39:130-174 (.<~~:::l~tion). 1867. ment of wounds and avoids the possibility 12. Mo! J. N., BreIl.!;:!, n., Simon, H., Beiler, J. of greater loss of substance and possible M .. ~nd Martin, G. J. Effect of trypsin on wound healing. Archives Internationales de injury to underlying structures which may Pharmacodynamie et de Therapie. May 1, result from surgical debridement mea­ 1957. sures. It may also be used in conjunction 13. Innerfield, 1., Schwartz, A. W., and Angrist, with surgical procedures to enhance heal­ A. A Fibrinolytic and anticoagulant effects of LV. crystalline trypsin. Bulletin N. Y. ing in certain difficult cases. Academy Medicine. 28:537-538. 195.2. Chymotrypsin, a new enzyme anti-in­ 14. Innerfield, 1., Angrist, A. A., and Schwartz, flammatory agent, ,is soon to be available A. W. Parenteral administration of trypsin. to the veterinary profession. It is fully as Journal American Medical Association. 152 (7) :597 -605. 1953. effective as adrenal steriod type hormones 15. Sherry, S., Titchener, A., Gottesman, L., Was­ in treating most comparable inflammatory serman, P., and Troll, W. The enzymatic dis­ conditions. It possesses the outstanding solution of experimental arterial thrombi in feature of being absolutely safe from any the dog by trypsin, chymotrypsin and plas­ minogen activators. Journal Clinical In­ side reactions in the patient and does not vestigation. 33:1303-1313. 1954. endanger the function or structures of the 16. Tagnon, H. J. Effect of intravenous injection endocrine system. of trypsin on the blood coagulation time in Both enzymes are economical to use in hemophilia. Proceedings Society of Experi­ mental Biology and Medicine. 57:45-47. 1944. routine practice procedures. They are ex­ 17. Rocha E. Silva, M. Concerning the mechan­ cellent forward steps in relieving the prac­ ism of anaphylactic and tryptic shock. Jour­ titioner from more crude or hazardous nal of Immunology. 40:399-404. 1941. methods of treating applicable conditions 16. Tagnon, H. J. Effect of intravenous injection in pets and domestic livestock. chymotrypsin and chymotrypsinogen. 1. Iso­ lation, chrystallization 'and general proper­ ties of a new proteolytic enzyme and its pre­ REFERENCES cursor. Journal General Physiology. 18:433- 1. Sumner, J. B. and Somers, G. F. Chemistry 458. 1934. and Methods of Enzymes. Academic Press 19. Werle, E., Kehl, R, and Koebke, K. Trypsin, Inc. New York. 1953. chymotrypsin, kallidin and bradykinin. Bio­ 2. Armour Laboratories. Unpublished data. chern. Ztschr. 321:213-220. 1950. 3. Reiser, H. G., Patton, R, and Roettig, L. C. 20. Jenkins, B. H. The use of intramuscular chy­ Tryptic debridement of necrotic tissue. Arch­ motrypsin in ocular conditions. Journal ives of Surgery (AM.A.). 63:568-575. 1951. Medical Association of Georgia. October, 4. Dragstedt, C. A. Digestion of living tissues 1956. by proteolytic enzymes. Science. 98:131-132. 21. Armour Laboratories. Chymar®, injectable 1943. enzyme with systemic anti-inflammatory 5. Tagnon, H. J. Enzymes in clinical medicine. action in peptic ulcer. Illustrated Case His­ New England Journal of Medicine. 249:650- tories. 1957. 657. 1953. 22. Gillespie, J. M. In press.

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