A bloodlike cocktail pumped through pigs’ vascular systems one hour after their deaths effectively supplied oxygen to tissues and partially restored cellular activity in multiple organs, including the heart, brain, and liver, a study published today (August 3) in Nature finds. The work follows a 2019 experiment in which the same group restored cellular function in the brains of pigs four hours after their deaths.

“Similar to the previous study in this work, we actually show that we can restore certain cell functions sometime after death,” study author Zvonimir Vrselja, a neuroscientist at Yale University, said a press conference, according to Gizmodo.

Vrselja and his colleagues’ research has implications for preserving organs for transplantation for longer periods compared to the current practice of using extracorporeal membrane oxygenation (ECMO) machines to keep the organs of deceased people alive until they can be donated, reports Nature. “We’re not saying it’s clinically relevant, but it’s moving in the right direction,” Vrselja tells the outlet.

See “Researchers Succeed in Keeping Disembodied Pig Brains Alive

The fluid pumped through the animals beginning one hour after their deaths is composed of equal parts of the animals’ blood and a cocktail of substances that mimic hemoglobin’s ability to carry oxygen plus approved and experimental drugs meant to reduce inflammation, prevent clotting, and minimize cell death, New Scientist reports. Tests on cells and tissue were conducted on samples from an experimental group of pigs and compared to others that were either connected to ECMO machines or to nothing.

Images comparing control electrocardiogram signals and tissue stainings (left) to those of the experimental group.<br><br>
Representative images of electrocardiogram tracings in the heart (top), immunostainings for albumin in the liver (middle), and actin in the kidney (bottom). The images on the left side represent the organs subjected to a control perfusion, while the images on the right represents the organs subjected to the experimental perfusion.
David Andrijevic, Zvonimir Vrselja, Taras Lysyy, Shupei Zhang; Sestan Laboratory; Yale School of Medicine

After several hours, the experimental group showed more effective fluid circulation and oxygenation of tissues throughout the pigs’ bodies compared to the ECMO group, Nature reports. The pigs in the experimental group had electrical activity and contractions in their hearts, while the EMCO group had none. In addition, the experimental group showed more metabolic activity compared to the EMCO group, including higher liver protein production and more glucose uptake in the cells of the brain, heart, and liver, the authors write in their study. 

“We have shown that cells don’t die as quickly as we assumed they do, which opens up possibilities for intervention. We can persuade cells not to die,” Vrselja tells New Scientist.

While the initial results are promising, Peter Friend, an organ transplant specialist at the University of Oxford, tells New Scientist that the best way to gauge the health of the animals’ organs would be to transplant them into another animal. “If they’re going after transplantation, just transplant the organ,” Friend says, adding that if the current work is successful “in resuscitating an organ which has suffered an otherwise fatal injury, then potentially this is very exciting.”