Cells and organs from dead pigs “come alive” for a few hours


Cells and organs of dead pigs “relive” for a few hours

Artistic illustration of organ perfusion and cellular recovery with OrganEx technology.

Scientists have succeeded in reviving blood circulation and functioning for a few hours of cells in the body of pigs dead shortly before, according to a study that gives hope for medical uses, but also raises ethical questions.

In 2019, a team of researchers based in the United States stunned the scientific community by successfully restoring cell function in the brains of pigs, a few hours after their decapitation.

In their In more recent research, published Wednesday in the journal Nature, these same scientists sought to extend this technique to the entire body of the animal.

They caused heart attacks in anesthetized pigs, which stopped blood flow and deprived their cells of oxygen. However, without oxygen, the cells of mammals die.

After an hour, they injected the dead bodies with a liquid containing the blood of the pigs (taken from their alive) and a synthetic form of hemoglobin – the protein that carries oxygen in red blood cells. They also injected drugs that protect cells and prevent blood clots from forming.

Blood began to flow again and many cells began to function again, including in vital organs like the heart, liver and kidneys, for the next six hours.

These cells were working hours after they died, when they shouldn't have been. This shows that the cells' disappearance can be halted, Nenad Sestan, the study's lead author and researcher at Yale University, told a press briefing.

Under a microscope, it was difficult to differentiate a normal, healthy organ from a treated organ post-mortem, added study co-author David Andrijevic, also from Yale.

The team hopes that this technique, dubbed OrganEx, can be used to save organs by prolonging their functioning, he explained. Potentially saving the lives of people awaiting a transplant.

OrganEx could also enable new forms of surgery by giving more medical leeway, according to Anders Sandberg of the University of Oxford.

But this technique raises number of questions, medical, ethical, even philosophical.

It could increase the risk that resuscitated people will then be unable to recover from a life-supporting state, warned Brendan Parent, a bioethicist at New York University's Grossman School of Medicine, in New York University. a comment published in parallel by Nature.

For Sam Parnia, of the department of medicine of the same university, this truly remarkable study also shows that death is a biological process treatable and reversible hours later.

To the point that the medical definition of death may need updating, judged Benjamin Curtis, a philosopher specializing in the field of death. Ethics at the British University of Nottingham Trent.

Given this study, many processes that we thought were irreversible would not be, he told AFP. And, according to the current medical definition of death, a person might not be truly dead for hours, with some processes lasting a time beyond the cessation of bodily functions.

This finding could also spark a debate about the ethics of such procedures.

Especially since almost all the pigs made powerful movements with their head and neck during the experiment, according to the account of Stephen Latham, one of the authors of the study. It was quite surprising to people in the room, he told reporters.

The origin of these movements remains unknown, but he has ensured that at no time had electrical activity been recorded in the brains of the animals, thus excluding a recovery of consciousness.

These head movements are nevertheless a major concern, said Benjamin Curtis, because recent research in neuroscience has suggested that conscious experience can continue even when electrical activity in the brain cannot be measured.

It is therefore possible that this technique caused suffering to pigs and that it could cause suffering to human beings if used on them, he added, calling for more research.< /p>


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