Chance discovery motivates scientist to consider sex differences in her heart research

Early curiosity and love of science blossomed into a fulfilling career for Dr. Elizabeth (Tish) Murphy, PhD, with the National Institutes of Health (NIH), who will be delivering the E.R. Smith Lecture on April 2 during the Libin Institute’s annual Tine Haworth Cardiovascular Research Day.

Murphy grew up in a small town in the mountains of Pennsylvania. One of four siblings, Murphy had a keen interest in chemistry as a teenager. That interest grew to include biochemistry after an engaging high school biology class piqued her interest in the subject that was to become her life’s work.

In the 1970s, Murphy went to the University of Pennsylvania but was bored with the labs she was taking. Rather than dropping out, she spoke to her professor. It turned out to be a fortuitous move for Murphy, who went to work in the lab of her professor’s husband, a researcher studying intracellular signalling in the heart and liver.

Murphy embraced the opportunity and soon fell in love with the research. She is thankful for the educators who gave her a chance. 

“A lot of life in any field is taking opportunities as they come,” she says.

In 1980, Murphy earned her doctorate in biochemistry/biophysics at the University of Pennsylvania, focusing on calcium’s role in intracellular signalling within the heart.

Murphy took another opportunity while working in that same lab, meeting and getting to know her now-husband. When he moved to North Carolina to take the MD-PhD program at Duke University, Murphy followed. She completed a postdoctoral fellowship at Duke and taught at the university for several years.

In 1984, she was hired as a staff scientist at the National Institutes of Health, where she has conducted heart research for the past 25 years. She is now senior investigator in the NIH National Heart, Lung and Blood Institute, one of 27 institutes funded by the U.S. government agency.

Part of her work involves understanding the role of calcium in a heart attack and looking at drugs to manage this process. Murphy explains there is a cascade of effects during a heart attack that starts when heart cells are denied oxygen, forcing the body to use glycogen for energy. However, breaking down glycogen creates lactic acid, which in turn leads to high concentrations of sodium within the cell. The cells exchange this excess sodium with calcium, causing cell death.

Her interest in the sodium-calcium exchange led her lab to an interesting discovery — that there are differences between the way male and female individuals respond to the excess calcium.

It all started with a "happy accident." Murphy explains when she was sent a number of female mouse models along with her normal male models, her lab discovered the males were more damaged during a heart attack than females. This led the lab down a new path that incorporates sex differences.

“We have discovered that estrogen is very protective,” says Murphy, noting her goal is to find drug treatments that will protect the heart from the changes caused by lack of oxygen.

Today, Murphy continues to incorporate sex differences in her research and is excited about what the future may hold. “It’s amazing how much more we know than we did,” she says. “Research has its ups and downs. There can be a lot of frustrations, but there are incredible eureka moments if you enjoy doing research.”

Murphy, who has earned numerous awards for her work, sits on numerous editorial committees and has published more than 220 articles, has some sage advice: “If you have a job that is interesting and fun, that is the greatest thing. If you really enjoy it, it isn’t work.”

The E.R. Smith Lecture is open to the public.