Two monkeys remain more than six months with pig hearts | Science

In 1964, Surgeon James Hardy performed the first heart transplant in history. The operation was also the first one in which the heart of an individual of one species was put in another, because the involved donor was a chimpanzee. The person who tried to save his life did not stay two hours after the intervention. Since then, surgeons and scientists have tried to develop methods to make animal organs possible in humans, but so far they have no technical difficulty. Today, in the magazine Nature, Scientists from the University of Munich explain how they managed to get two baboons to survive three months with a porcine heart in their bust and two more to reach six before being sacrificed. The results, which increase by more than three of the previous record of 57 days of survival, approach the possibility of converting pigs into a source of hearts to transplant humans who need them.

When a person has a terminal heart disease, transplantation is the only durable solution and pigs would be an option in the face of a shortage of human donners. However, to make the organs of one-kind work in another is not easy. First, the authors of this work used genetically modified pigs to make their hearts resemble those of the bobones and not suffer from the rejection of their immune system. In addition, the monkeys are treated to suppress their defenses and ensure a good reception. These types of treatments, which are commonly used in transplants, increase the risk of dangerous infections, which did not occur in the experiment.

Another step that can explain the success of the team coordinated by Bruno Riimart, from the University of Munich, is the system to maintain the integrity of the organ in the process. Instead of holding the heart cold, they pumped a solution refrigerated with oxygenated blood, nutrients and hormones. In the first part of the experiment, which was borne by three phases, the scientists noticed that pig heart grew within the bobones until they died a little more than a month after the operation. To avoid this problem, they reduced the blood pressure of the monkeys, which is higher than that of the pigs, to achieve the optimum level for their new heart, and pharmacological and hormonal treatments are designed to avoid excessive cardiac development.

Cristina Costa, a researcher in the Biomedical Research Institute of Bellville (IDIBELL), in Barcelona, ​​and a specialist in the type of transplants among species, shows that "the field was slightly stuck due to the lack of a good animal model This study establishes one new "to bring the techniques to trials with humans. "It needs a good animal model to test the organs that are generated in the pigs modified with the new genomic editing technologies," he concludes.

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