Synthetic progestin damages, estrogen protects blood vessels in animal model.

2004 JAN 1 - (NewsRx.com & NewsRx.net) -- Synthetic progestins may be the major cause of harmful side effects reported with hormone replacement therapy.

University of South Florida researchers used a novel imaging technique to show that progestins caused toxicity while natural progesterone and estrogen did not show toxicity to blood vessels in live animals.

"Our findings can lead to the development and screening of synthetic hormones to find a safe progestin that will ultimately give women safer options than are currently available for hormone replacement therapy," said Tom Thomas, MD, PhD, co-principal investigator and lead author of the study published in the December 11, 2003, issue of Climacteric, the journal of the International Menopause Society.

"This is experimental evidence that supports scientists who believe estrogen with the right formulation is good for some women, depending on their other risk factors," he said.

The novel imaging technique was developed by Thomas and Johannes Rhodin, MD, PhD, co-principal investigator. It took 3 years for Thomas and Rhodin to combine video microscopy with fluorescence and electron microscopy. By labeling blood cells with a fluorescent tag, the team observed blood flow, blood vessel structure, and activities of various blood cells in real time in a live animal. After one dose of medroxy progesterone ...