Much research involves male animals. Fortunately, that’s changing – and with interesting results! Allergic anaphylaxis is more severe in female mice than in males – because of estrogen.
Researchers at the National Institute of Allergy and Infectious Diseases, National Institutes of Health, knew that women tend to have more severe anaphylactic reactions than do men, but no one really knew why. By studying allergic reactions with female mice, they have figured out an important component of this difference.
They found that female mice had more severe anaphylaxis than their male counterparts, just like humans! Estrogen regulates the expression of endothelial nitric oxide synthase (eNOS) which is an enzyme that causes some of the symptoms of anaphylaxis. When the females were treated with a compound that prevented estrogen binding or had their ovaries removed (thus removing the source of estrogen), their reaction was no stronger than the males’.
This finding is an important advance in the knowledge of allergic reactions and how they can be effectively treated. It opens up a whole new avenue of possibilities that can be explored to improve treatment options – and preventative measures! – for human anaphylaxis.