Organ donation and transplantation is a big discussion at the moment. Wales have trialled an opt-out system to help boost numbers on the organ donation list, and similar plans are being discussed for England and Scotland. Last month, Addenbrookes hospital in Cambridge were the first in the UK to use the ‘perfusion machine’ for liver transplants, as this keeps the donor organ pumped with blood, nutrients and medicine. They have started using this technology as donor organs that are stored in ice can become damaged and unstable as a result.
How to store and keep organs for transplants is still a huge problem in the process, as at the moment there is a very small time-frame in which they can successfully be used. Kidneys are usually stored for up to 30 hours, as after this time the tissue begins to deteriorate and affects the ability to function normally. Livers, lungs, and hearts have an even shorter shelf-life.
A new study has begun to explore how the process of hibernation could help with research into prolonging the shelf-life of donated organs. In this new study, researchers from the National Eye Institute in the United States focused on ground squirrels, a small hibernating rodent native to North America. They discovered that the animals dramatically lowered their heart rate and body temperature to enable them to survive the winter months. Scientists hope that by understanding how the cells of hibernating animals adapt to cold temperatures, similar processes could be applied to human tissue, prolonging the viability of organs prior to transplantation.
The scientists reprogrammed the cells of ground squirrels into stem cells under a microscope, where they observed how the cells adapt to the cold. They discovered that one reason for the hibernating creatures’ resilience to low temperatures was related to the mitochondria, also known as the ‘powerhouse’ of the cell. The experiment showed that when humans are exposed to cold temperatures, the mitochondria in our cells secrete a by-product of metabolism called Reactive Oxygen Species, or ROS which uses up more of our energy in a short space of time. In comparison, the mitochondria of hibernating squirrels maintain low ROS levels, prolonging the use of energy.
Also by researching and understanding hibernation and cold adaptation, scientists hope this could lead to improvements in induced hypothermia. This process deliberately reduces a person’s body temperature to protect the brain after a cardiac arrest or brain injury, however it is still controversial as it can cause cold-induced cellular damage. With further research, it is hopeful that induced hypothermia will be improved to be used as a viable treatment, and also to help prolong the shelf life of donor organs.
It is very early days for this new research, and it may well be a few years before we see any of the research come to fruition. In the meantime, be sure to register on the organ donor list!