============================================================ Transplants and Diabetes              <Uploaded: January 24> ------------------------------------------------------------  Three Toronto scientists have developed an organ transplant procedure that could, among its many benefits, reverse diabetes.   The procedure was developed by Bernard Leibel, Julio Martin  and Walter Zingg at the University of Toronto and the  Hospital for Sick Children.  The story of their work began in 1978, when they delved into research which had never before been tried. They wanted to  determine if the success rate of organ transplants would increase if the recipient was injected with minute amounts of organ tissue prior to the transplant. The intention was to adapt the recipient to the transplanted tissue and thereby raise the threshold of rejection.  In the case of the diabetes experiment, this meant injecting  rats with pancreatic tissue before transplanting islets of  Langerhans, small clusters of cells scattered throughout the  pancreas which produce insulin, glucagon, and somatostatin.  In their first experiment, outbred Wistar rats were injected  with increasing amounts of minced pancreas from unrelated  donor rats for one year while a control group was left  untreated. Then both the treated and control groups received  injections of approximately 500-800 islets of Langerhans from unrelated donors. Of the five treated animals, two  became clinically and biochemically permanently normal. Six months later, Martin examined the cured rats and found  intact, functioning islets secreting all of their hormones,  including insulin. None of the controls were cured.  Encouraged by their first results, Leibel, Martin, and Zingg decided to repeat the experiment with rats with much  stronger immune barriers (higher levels of rejection). Seven rats out of nine were cured. "We set up a protocol and  worked patiently with small numbers," says Leibel, "but the results are indisputable."  In addition to reversing diabetes, there are two other  benefits to the pre-treatment procedure, according to the  scientists. The first is that the pancreas produces all the other hormones of a normal pancreas, not just insulin. The  second benefit is that the transplant recipient doesn't have to take immunosuppressive drugs, which are so toxic for  diabetics. At present, diabetics who receive a transplanted pancreas must take such drugs for life.  The scientists eventual goal is a human trial, but they  admit it will be years before such a study is conducted. The  obvious benefit for diabetics, if human trials prove  successful,  would be a return to a normal life without  dietary restrictions or insulin shots.  But to Liebel, the  most important reason to continue research is to eliminate the debilitating, degenerative diseases such as kidney, eye and heart failure that eventually plague the aging diabetic. 