By AMERICAN HEART ASSOCIATION NEWS
Numerous studies have determined that cocaine use increases blood pressure and the hardening of arteries in its users, but now new research has helped pinpoint just how that actually happens on a molecular level – at least in mice.
The discovery opens up potential methods of fighting some of the physical damage cocaine inflicts on a user’s cardiovascular system. It may also provide hope in finding ways to ward off similar destruction often seen in the aging bodies of non-drug users.
In a study published Monday in the journal Hypertension, three groups of mice received daily injections of cocaine, a cocaine equivalent that does not enter the brain but still directly impacts other organs as well as the cardiovascular system, or saline for 10 days. Blood pressure increased in the mice shot with cocaine and the cocaine equivalent. These two groups also saw an increase in aortic stiffness – a hardening of arteries normally associated with aging and closely linked with high blood pressure.
But researchers also discovered that cocaine exposure increased the production of oxygen-derived free radicals, which are normally unstable atoms that, at lower levels, can help the body neutralize harmful organisms like viruses or bacteria.
But high levels of free-radical production can contribute to illness, aging and, among cocaine-injected mice in the study, damage to the body’s heart and blood vessel system.
“What this study does is it actually fills in some of the details that tell us, at a molecular level, how repeated use of cocaine causes various adverse effects,” said cardiac physiologist Steven Houser, director of Temple University’s Cardiovascular Research Center, who was not involved in the study.
“We knew that cocaine can increase blood pressure, and we knew that cocaine can cause aortic stiffening. What we didn’t know was exactly how it did all that, and this study gives us some insight into what happens in the middle, between cocaine abuse and aortic stiffness.”
Findings about cocaine-induced health problems have been well documented in previous studies, the study noted. Cocaine use leads to higher blood pressure, stiffer arteries and other problems, ranging from an irregular heart rhythm to heart attacks and strokes.
But “discovery of this novel cocaine … pathway provides a potential new therapeutic avenue for treatment of cocaine abuse-related (cardiovascular) disease,” the researchers wrote.
Currently, there is no specific medical treatment for cocaine abuse “mainly because we do not understand the mechanism causing the damage” to the body, said Dr. Chunming Dong, the lead author of the study and a cardiologist at the University of Miami’s Miller School of Medicine.
“Our research defines a pathway that was not really known before, so now we have another tool in our box to counteract the effects of cocaine,” he said.
An estimated 1.9 million Americans age 12 and older use cocaine, according to 2016 data from the National Survey on Drug Use and Health.
The findings open up potential therapies to reduce or even block cocaine-induced damage on the body. But scientists also might be able to apply those treatments on a wider scale to treat high blood pressure and aortic stiffness in the nation’s aging population.
“That would be the broad potential application,” Houser said. “But there are lots of things that need to be done from this mouse study to make it something that would have impact in people.”
Dong agreed, chiming in that he and other scientists involved in the study continue to pursue additional research to follow up on their work.
“I do not want to overstate these findings. It’s very important to remember that all animals, especially humans, are very complicated,” he said. “I do not believe that one pathway accounts for all the cocaine effects in its entirety.”
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