Inhibiting a protein protects against heat stroke

Until now, we have not had any specific treatment for the often fatal effects of heat stroke.

A group of researchers from the Institut Municipal d'Investigació Mèdica (IMIM-Hospital del Mar), in collaboration with researchers from the Centro Regional de Hemodonación and the General Surgery Service of the University Hospital Virgen de la Arrixaca in Murcia, have just published the results of an experimental project that could mean an important advance in the protection against the effects of heat stroke in the journal Critical Care Medicine.

Heat stroke is defined as an increase in body temperature to above 40 ºC followed by hypothermia (drop in temperature) that is a direct result of an elevated ambient temperature. When a person has heat stroke, his/her body reacts in a similar way as it would for a general inflammation caused by a systemic infection, for example. The person's body temperature rises, producing a systemic inflammation and disseminated intravascular coagulation, which leads to the failure of multiple organs, which in many cases leads to death.

The main finding of the research carried out was the identification of a protein, PARP-1 (poly ADP-ribose polymerase), in the physiopathology of heat stroke. The researchers subjected two groups of mice to a temperature of 42 ºC for a period of 45 minutes. One group of normal mice served as the control, while the other group of mice was inoculated with a PARP-1 inhibitor. The body temperature of both groups was then measured, as well as inflammatory markers and protein levels. With this, the researchers were able to show for the first time that the inhibition of the action of this protein produces a higher tolerance to ambient heat, capable of attenuating the effects of heat stroke and thus at the same time capable of diminishing the mortality associated with this cause.

All signs point towards the temperature on Earth increasing due to global warming. High-temperature situations, such as those experienced in 2003, could be repeated in the future. On that occasion, there were between 22,000 and 45,000 deaths throughout Europe in a single week that were related in varying degrees to the unusual increase in ambient temperature. The temperature increase withstood that summer affected mortality rates in the city of Barcelona, with some 400 deaths being related to the increase in ambient temperature. This increase in mortality primarily affected people older than 70 years.

The results of this research open an important door to the research towards a promising therapeutic method, which has not existed until now, but which is basic for those people threatened by a sudden increase in ambient temperature.