Once again a mistake leads to an important scientific discovery, say researchers at the University of Alabama, Birmingham. Estrogen, a female sex hormone, may prolong survival following blood loss. However, this discovery only occurred as a result of a gender "error."

In 1997, after carefully designing an animal experiment, Dr. Irshad Chaudry, director of the Center for Surgical Research, received the wrong shipment of mice. As Chaudry explained in a UAB press release, his colleague noted the mistake and raised objections. Because their hormone levels were too variable, this type of rodent would be entirely unsuitable for their planned experiment, argued Dr. R. Zellweger, a post-doc researcher in his lab. The results would be too confusing to interpret… the mice were all wrong! However, Chaudry suggested they run the experiment instead of waiting for another shipment.

What type of mice had arrived in the lab? Females.


What Chaudry had been studying in 1997 was sepsis, a bacterial blood infection and serious complication often seen in patients who hemorrhage following a trauma. Unusually, these infections can strike days, weeks, or even months after severe blood loss. For patients, sepsis causes single or multiple organ failure, long hospital stays, and, in the worst cases, death. To examine how sepsis produces organ failure, Chaudry and Zellweger had created an experiment involving male mice yet received females by mistake.

Conducting their experiment on the female mice, the results thrilled the researchers: All of the female mice resisted sepsis without any treatment. Testing their results by repeating the experiment with another group of mice, the opposite result occurred. This second set of female mice died.

Following Zellweger’s brief “See-I-Told-You-So” moment, the two colleagues carefully examined the mice. They realized the first group had all been in the same phase of their menstrual cycle, the moment when estrogen levels are at their peak.

Experimenting further, the team figured out that a dose of synthetic estrogen could protect mice, both males and females, against septicemia. Tracing the cause, they observed how estrogen influenced responses of the immune system and cardiovascular system, which typically are depressed after trauma. Next, the researchers tested estrogen to see how it might affect another deadly trauma outcome, blood loss.

Even after massive blood loss, estrogen significantly improved heart performance and liver function (following standard resuscitation procedures), the researchers discovered. A shot of estrogen might prolong survival, Chaudry hypothesizes, even in cases when a victim of trauma is not immediately transported to a hospital, such as happens often with soldiers on the battlefield. Having received a grant from the Department of Defense, he and his colleagues will begin testing synthetic estrogen in humans.

As Chaudry foresees it, the hormone could be carried in a small autoinjector for battlefield emergencies. Strangely, this scientific discovery resulting from gender confusion and laboratory mishap may someday save lives.