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By Sherry F. Pruitt

JONESBORO -- The health of Arkansans is behind the research being conducted by two of Arkansas State University Biosciences Institute scientists.

Dr. Anne Grippo, associate professor of biological sciences, and her team concentrate on cardiovascular health when nicotine and weight loss agents are combined, and Dr. Malathi Srivatsan, assistant professor of biological sciences, and her student research associates focus on the direct effects of nicotine on neuron development. Information for this report was obtained through e-mail correspondences.

Grippo

Grippo's research focuses on the effects of nicotine in combination with weight loss agents -- such as ephedra with caffeine -- on cardiovascular health.

"Work on this project began in 2003, and included three graduate students, one undergraduate honors student, and several undergraduate researchers," she said.

Grippo's research was an extension of a project originally funded in 2002 by Arkansas Biotechnical Research Infrastructure Network in collaboration with researchers at the University of Arkansas Medical Sciences' College of Pharmacy. It was funded in 2003 and 2004 by grants from the Arkansas Biosciences Institute.

The ABI group detected some changes in their research, Grippo said.

"We have found that ephedra alone does not significantly affect blood pressure, heart rate, or heart tissue in rats; little effect was seen when ephedra was given to animals first treated with nicotine," she said. "However, when nicotine was given, followed by ephedra together with caffeine, some regions of the heart showed signs of inflammation, and we observed electrocardiogram changes, particularly in females, with just one to three doses of stimulant," Grippo said.

Srivatsan

Research conducted by Srivatsan's team deals with the effects of nicotine on the unborn.

"We decided to determine the effects of exposure to various concentrations of nicotine for different periods of time on survival and growth of the neonatal sympathetic autonomic neurons," she explained.

Parts of cells taken from 1-day-old rat pups are isolated and dissected under a microscope.

"These clumps of neurons are then carefully dissociated in to individual neurons under sterile laboratory conditions using specific enzymes. We then grow these neurons on culture dishes, feeding them with cell culture medium containing nutrients similar to those present in blood plasma," Srivatsan said.

The culture dishes are divided into control and experimental groups, she added.

Experimental dishes are treated with various concentrations of nicotine for certain lengths of time.

"Our current results show that nicotine equivalent to the level present in a heavy smoker's plasma significantly reduces the growth of nerve fibers from these developing neurons," she explained.

"This must be due to nicotine's ability to change nicotinic receptor levels and their functional status. Hence we have now started to investigate the nicotinic receptor expression patterns in these sympathetic neurons (part of the autonomic neurons that are well known for their significant function of regulating blood pressure) which are being exposed to nicotine," she said.

The cell culture experiments help researchers to identify the direct effects of nicotine on neuron development. Srivatsan's research will be valuable to health care professionals who treat pregnant women.

At nearly 19 percent, Arkansas ranks the highest among the states in the proportion of women who smoke during pregnancy as compared to the national average of 12 percent, Srivatsan said.

"This puts Arkansas as the third-highest state for mothers smoking during pregnancy," she said.

Researchers have cited a host of problems and disorders that are associated with smoking mothers, she added.

sherry@jonesborosun.com