Federal grant advances professor's research into dioxin-heart disease link

The National Institute of Environmental Health Sciences (NIEHS) has awarded Rebecca J. Sommer, assistant professor of biology at Bates College, a grant of $132,883 to investigate the impact of dioxin on early cardiac development.

Awarded in September, the two-year grant will support Sommer’s research at Bates and at the University of New Mexico, where she will work in 2003. Sommer, a Litchfield resident, is investigating the cardiovascular disease typically found in chickens exposed as embryos to dioxin. The research could indicate a relationship between congestive heart failure in humans and exposure to dioxin or similar toxic chemicals that accumulate in tissue from environmental exposure.

“Knowing the mechanism of how this happens in chickens will make us much more confident about saying whether we think dioxin could contribute to cardiovascular diseases in humans right now, with what we’re exposed to in our diet,” Sommer says. A potent pollutant, dioxin makes its way up the food chain to us through foods like meat, milk and cheese, and is retained in body fat.

Sommer is focusing on the “beta-adrenergic receptor,” a protein that controls the heart’s response to varying workloads. (It’s the same protein controlled by prescription “beta-blocker” drugs.) She hypothesizes that dioxin interferes with this cardiac signaling system and sets off, in her words, a “downward spiral” of heart function leading to failure. Her aim is to try to identify the source of that interference, which could involve impacts on the amount or the chemical properties of the receptor, or the heart’s sensitivity to it.

In January, Sommer heads to the University of New Mexico, in Albuquerque, where she will work with Mary Walker, a leading researcher in developmental toxicology. There she will treat chick embryos with a range of dioxin doses and other chemicals that will help determine how the dioxin affects the embryos’ hearts. In April, Sommer will bring the treated hearts back to Bates for analysis during the following year and a half.

Sommer is from New London, Wisc., and did her undergraduate and graduate studies at the University of Wisconsin-Madison, where she earned her doctorate in pharmacology. Her doctoral research investigated how dioxin administered to rats while they were in the uterus or still nursing affected the animals’ reproductive tracts as adults.

She is one of the rare researchers to receive the award from the NIEHS, one of the National Institutes of Health, on the first application. Delighted by the support for her research, she is also pleased that the award will enhance the academic offering at Bates. This type of work is more often done at major research universities than small liberal arts colleges.

“It would be very difficult to compete with laboratories that have graduate students, post-docs and research scientists who do this full time,” she says. The affiliation with Walker and the University of New Mexico also benefits Bates and its students, she adds. For a researcher, “it’s very important to have these outer links,” she says. “If a faculty member stays current in research, it really improves her teaching.”

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