Scientists managed to revive the functions of pig cells hours after their death

Scientists have been able to reactivate blood circulation for a few hours in cells from dead pig bodies and have managed to revive their work, according to a study that opens up hope of medical uses for the experiment, but also raises ethical questions.

In 2019, a team of researchers from the United States surprised the scientific community by reviving the functions of cells in the brains of pigs a few hours after they had been slaughtered.

And the scientists themselves sought in their latest research, published Wednesday in the journal Nature, to extend this technique to include the entire body of the animal.

To do this, the scientists caused a heart attack in anesthetized pigs, which stopped blood flow and deprived their cells of oxygen, knowing that mammalian cells die in the absence of oxygen.

Within an hour, they injected animal carcasses with a liquid containing blood taken from live pigs, a synthetic form of hemoglobin, the oxygen-carrying protein in red blood cells, as well as drugs that protect cells and prevent blood clots from forming. .

This got the blood flowing again, and several cells returned to function over the next six hours, including those in vital organs such as the heart, liver, and kidneys.

Lead author of the study, Yale University researcher Nenad Seistan, said during a news conference that “these cells were working after hours when they weren’t supposed to be working, and this indicates the possibility of stopping the demise.” of the cells”.

As for study co-author David Andrejevic, also of Yale University, he pointed out the difficulty of distinguishing under the microscope between a normal, healthy organ and one that was treated after death.

He explained that the team hopes that the use of this technique called “OrganEx” will be possible to “save organs” by prolonging their work, which can save the lives of people waiting for transplants.

Organix may also enable new forms of surgery by providing “greater medical leeway,” according to Anders Sandberg of the University of Oxford.

However, this technique raises controversy for a number of issues related to medicine, ethics and even philosophical concepts.

In a commentary published by Nature on the sidelines of the study, Brendan Barnett, a bioethicist at New York University’s Grossman School of Medicine, warned that this technology could lead to “increasing the inability of resuscitated people to wean themselves off biomedical care.” .

For his part, Sam Parnia, from the Department of Medicine at the same university, pointed out that this study, which he described as “important”, also shows that “death is a biological process that can be treated and reversed after hours.”

Even the philosopher who specializes in ethics at Britain’s Nottingham Trent University, Benjamin Curtis, argued that the medical definition of death could use an update.

“In light of this study, it turns out that there are things that we thought were irreversible, but they are not,” he told AFP. He added: “According to the current medical definition of death, a person may not have died hours earlier,” since some body processes continue to function for a certain period of time after their functions cease.

This finding may also generate a debate about the ethical compatibility of such procedures.

Study co-author Stephen Latham noted that strong movements of the pigs’ heads and necks were observed during the test. “It was very surprising to those in the room,” he told reporters.

The source of these movements is unknown, but Latham confirmed that no electrical activity was recorded in the animals’ brains at any time, ruling out that the animals regained consciousness.

Benjamin Curtis confirmed that there is “great interest” in these head movements, because recent research in neuroscience indicates that “a conscious experience can persist even if no electrical activity is detected in the brain.”

“Therefore, it is possible that this technique has caused suffering in pigs and could cause suffering in humans if applied to them,” he added, calling for more research on the matter.