When the body loses a lot of blood, it tries to compensate by going into shock. This is a set of emergency measures to raise blood pressure and conserve energy, such as increasing heart rate and shutting down expression of some proteins. However, if the body stays in shock for more than a short time, it can lead to organ failure, and death soon follows.
Recent studies have suggested that around 6 or 7 per cent of genes change their expression in response to shock, via the removal of "epigenetic", chemical additions to the genome called acetylations. As histone deacetylase (HDAC) inhibitors can prevent the removal of such acetylations, Alam wondered if these drugs might improve survival after blood loss.
His team previously showed that valproic acid, an HDAC inhibitor already used to treat epilepsy, increased survival rates in rats that had lost a lot of blood. It seemed to be doing this by preventing acetylation, causing certain "survival pathways" to remain switched on.
Now Alam has repeated the study in pigs. He anaesthetised the animals, drained 60 per cent of their blood, and subjected them to other injuries before giving them a saline transfusion. He then injected some of the pigs with valproic acid, gave others a blood transfusion and left the remainder untreated.
Just 25 per cent of the pigs receiving only saline survived for 4 hours - the typical time it takes to get hospital treatment - while 86 per cent of those injected with valproic acid survived. All those that had a blood transfusion lived
Poor pigs. Mmmm bacon.
The drug hasn't been tested on humans yet so they don't know if it will work on humans in the same way.
