DHEA Receptor Identified in Vascular Endothelial Cells

A receptor for the adrenal hormone dehydroepiandrosterone (DHEA) has been located in the cells that make up the inner lining of blood vessels. DHEA and the closely related DHEAS are made mainly in the adrenal gland and circulate in the bloodstream in higher concentrations than any other steroid hormone, including estrogen or testosterone. DHEA production declines after the age of puberty, dropping to around 20% of peak levels by age 75.

A report appearing in the June 14, 2002, issue of the Journal of Biological Chemistry describes how investigators from the University of Iowa (Iowa City, USA; www.uiowa.edu) chose a novel approach to find the elusive DHEA receptor. Rather than working with immune or liver cells, as is most often done, they searched for the receptor in the cells comprising the vascular endothelium. Moreover, the receptor was found localized on the exterior surface of the cells rather than the interior surface, where hormone receptors are usually found.

"The significance of our study is that it provides a scientific basis for further study of the DHEA action in humans,” said the study's lead investigator Dr. Joseph Dillon. "Our findings show that there is a receptor for DHEA on the inner lining cells of blood vessels. The receptor responds to levels of DHEA that circulate normally within the bloodstream and links DHEA to the production of nitric oxide. Unlike research with all the other major hormones and steroids, no one had previously been able to identify a receptor for DHEA in cells.”

The next step will be to completely isolate the receptor. This will allow testing of DHEA analogues in order to eventually develop medications that could have beneficial effects in a wide range of diseases, including cancer, heart disease, obesity and diabetes.



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