Heart drugs may show promise in fighting muscular dystrophy, study finds

(Dennis Thompson – HealthDay News) — Common type medications to treat heart problems could improve one of the most common forms muscular dystrophyproposes new research in mice.

The researchers explained that myotonic dystrophy type 1 (DM1) is caused by abnormal RNA that affects the function of calcium channel receptors, which help convert nerve cell impulses into chemical signals that control muscle movement.

Given the above, they believe that a type of heart medication called a calcium channel blocker may eliminate the “noise” caused by this abnormal RNA.

These drugs successfully alleviated the symptoms of T1D in laboratory mice bred with the genetic problem that causes this form of muscular dystrophy.according to the results, which were published in the Jan. 2 issue of the Journal of Clinical Investigation.

“We believe calcium channels are a new therapeutic target, and if we can target them pharmacologically correctly, it will improve muscle function and health.”– the researchers wrote.

People with T1D suffer from muscle weakness and prolonged muscle tension, which makes it difficult for muscles to relax after exercise, the accompanying notes say.

The muscle problems caused by this disease affect the eyes, heart and brain, ultimately leading to problems with walking, swallowing and breathing.

More than two decades ago, study co-author Dr. Charles Thornton, a neurologist at the University of Rochester Medical Center, discovered how a genetic defect causes T1D. According to Thornton’s earlier research, the genetic stutter results in thousands of repetitions of code on a segment of chromosome 19.

This defect in turn causes the accumulation of abnormal RNA, which interferes with healthy muscle function. To study this cycle and better understand T1D, the researchers bred laboratory mice that had four genetic defects found in T1D, specifically in genes associated with calcium and chloride channels.

“Myotonic dystrophy is a truly complex disease that can be viewed almost as a collection of many diseases,” study co-author John Luke, an assistant professor at the University of Rochester Medical Center, said in a University of Rochester press release.

They then tried treating these mice with calcium channel blockers, which are commonly used to treat high blood pressure, heart rhythm problems and migraines.

The researchers reported that verapamil, a calcium channel blocker used to treat blood pressure and chest pain, caused the mice to quickly regain muscle function and appear as healthy as normal laboratory mice.

“Our study also suggests that muscle wasting in T1DM is potentially ameliorated by common clinically available calcium channel blockers, and that calcium channel modulation is a potential therapeutic strategy,” Luke said.

However, the researchers noted that verapamil should not be considered for use in people with T1D because it may have harmful side effects. Additionally, studies in mice don’t always work in humans.

“Our goal now is to find the right, safe calcium channel blocker that does the job, and we believe it exists.” the researchers concluded.

More information

The Cleveland Clinic has more information about calcium channel blockers.

SOURCE: University of Rochester Medical Center, press release, January 2, 2023.