Oxygen is vital for maintaining normal cell function. It’s so important that even a few minutes without oxygen can cause a buildup of acid in the body. And that can lead to cell death and organ injury.
Insufficient blood flow that can’t provide oxygen to organs and cells—which is called “ischemia”—is a major hurdle to overcome when a human donor’s organs are being retrieved for transplant.
Once the heart stops pumping blood around the body, there is only a small window of time when organs can successfully be recovered before ischemic-related organ injury occurs. Organs that are damaged due to ischemia cannot be transplanted, which causes the already small pool of organs available for people on long waitlists to become even smaller.
There have been numerous attempts by researchers to maintain or recover cellular viability in isolated organs and cells even after ischemic exposure. However, this is incredibly tough to do in a whole body—it’s very difficult to artificially pump blood throughout the entire circulatory system. Minimizing damage to blood vessels when blood is reinfused is a challenge too.
A new study published in Nature attempted to prevent this type of organ injury that occurs after the heart stops beating. The window for organ recovery in humans from when the heart stops pumping blood around the body is typically mere minutes. In this study, researchers infused pigs with a special fluid after death and ischemia had occurred. The fluid contained drugs that could prevent further tissue injury and a buildup of toxins and that would rejuvenate injured or dying cells.
Blood supply is not only important to deliver oxygen to cells but also to remove waste products from normal cellular processes. Think of blood supply as a postal service that delivers important packages but also removes your garbage on the same trip. When that supply is shut off, waste can build up and create a toxic environment in the organ. The cell-protective fluid was made specifically to be able to counteract the accumulation of the metabolic waste products from ischemia, while also containing cell-reviving drugs.
The results were remarkable. Six hours of the treatment was able to maintain tissue and organ integrity, decrease cell death and even restore cellular function in vital organs such as the liver, heart and brain.
This new and innovative research hopefully will increase the window of opportunity when organs can be successfully transplanted without ischemic damage. Given the shortage of organ donors, this could make many more organs available for transplant.
Rory Cunningham, PhD, is a former postdoctoral fellow at the National Cancer Institute and a scientist at the liver therapeutics company Ochre Bio. His research involves developing and phenotyping models of human liver perfusions.