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19 October 2005
Speculation Over Mystery Hormone Behind Preeclampsia 
Preeclampsia, typically starting after the 20th week of pregnancy, is a major cause of fetal complications, including low birth weight, premature birth and stillbirth. It can also lead to seizures, known as eclampsia, which are the second leading cause of maternal death in the United States. It occurs most often in first-time pregnancies and is related to increased blood pressure and protein in the mother's urine, resulting from kidney problems. It affects the placenta, and can affect the mother's kidney, liver and brain. Now, researchers at the University of Cincinnati (UC) say they have found evidence of a hormone that appears to be responsible for certain types of high blood pressure (hypertension), and could also cause preeclampsia. Their work, reported in the Proceedings of the National Academy of Sciences, is now focused on identifying the hormone responsible, which they believe is produced in very small, but highly potent, amounts. Identifying and neutralizing this "new player" in the mechanism of hypertension could provide a breakthrough in the prevention of preeclampsia, which so far has been essentially untreatable. Their research, said UC scientist Jerry Lingrel, is now concentrating on a human enzyme known as the "sodium pump," which is known to be involved in the regulation of blood pressure. The sodium pump is the target for a group of drugs called cardiac glycosides, which are commonly used to control congestive heart failure by increasing blood pressure. Cardiac glycosides, used by physicians for centuries to treat congestive heart failure, have largely been obtained from external sources like plants. The researchers speculate that the survival of this enzyme through thousands of years of evolution means that it must also be present for something other than externally derived, man-made medications. Consequently, they have been looking for a naturally occurring, internal or "endogenous" control agent. This agent is likely to be a hormone in the body that regulates blood pressure by interacting with the enzyme. Once the hormone is identified, which the researchers say should be a relatively routine, although painstaking procedure; its level could be manipulated to control blood-pressure problems such as preeclampsia. "The site, with its ability to regulate blood pressure, is there to respond to something that occurs naturally in the human body. We're now very close to finding it," said Lingrel. "This new player, when we identify it," said co-researcher Iva Dostanic-Larson, "is highly likely to be overproduced in preeclampsia. The next step is to chase down the hormone." Source: University of Cincinnati
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