Chemical May Aid Tendon Surgery
This report is reprinted with permission from The Evening Star, Washington, D.C., March 29, 1967.
A chemical extracted from the sweet pea plant may enable surgeons to mend broken tendons so that they do not adhere to scar tissue and thus do not become stiff.
Called BAPN-it rhymes with happen and is short for beta amino-propionitrile-the chemical causes widespread illness in turkeys and cattle when it is added to their diets. In this disorder, the body manufactures the raw materials of collagen, the major protein of the connective tissues, but cannot assemble them in the proper way.
Since collagen is a principal component of scar formations, the idea is that small amounts of BAPN -by temporarily preventing collagen assembly-will give tendon repairs a fighting chance to heal unimpeded and intact.
BAPN was first used on humans by Drs. Albert Sjoerdsma and Harry Keiser of the National Heart Institute in Bethesda, Maryland, in 1965. After extensive tests on animals, they had hoped it would alleviate systemic scleroderma, a progressive and often fatal disorder in which overproduction of collagen makes the skin so rigid that the patient becomes a prisoner inside.
This hope proved futile. The drug is too toxic for month-in, month-out treatment of this chronic disease. But the National Institutes of Health team was able to show that it can safely be taken by mouth for short periods of time. And this led Dr. Erle E. Peacock, Jr., a University of North Carolina surgeon, to make some experiments of his own.
Bound by Scar Tissue
Peacock specializes in repairing broken tendons caused by serious cuts, the kind that result from auto or industrial accidents or the mishandling of an ax. Like many surgeons, he had long been troubled by the fact that even the most perfectly repaired tendon tends to become bound by scar tissue to the surrounding tendon sheath so that its mobility is lost. Although many have sought to prevent this by wrapping the tendon in plastic or other materials, successes have been rare. Thus Dr. Peacock decided that if BAPN could slow the assembly of collagen and in turn the formation of scar tissue, the problem might be solved.
In a telephone interview yesterday, Peacock said that he and his colleagues had immobilized the legs of dogs and rats in splints, much as people are put into casts when they break an arm or leg. The tests showed that the animals who got BAPN produced collagen that was flimsier than those that did not get the drug. They also became less stiff.
The scientists also experimented to see what effect the BAPN would have on wounds. With rats as patients, they were again able to show that injections of the sweet pea extract slowed the formation of collagen so that incisions healed with less rigid scars.
Peacock now has permission from the Food and Drug Administration to try the drug on patients, although he does not know how soon he will do so.
In the current issue of the New England Journal of Medicine, however, he says that controlled lathyrism, as the technique is known, is "not science fiction."
"With new understanding and ability to control each step of the healing phenomenon," he adds, "highly specialized problems. . . will become more controllable by physiologic and pharmacologic means and less dependent upon highly developed technical (i.e., surgical) skills."
Judith Randal is a Staff Writer for The Evening Star