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

(Dennis Thompson- HealthDay News) — Kind of normal Medicines to treat heart problems may be able to correct one of the most common forms of Muscular dystrophysuggests a new study in Rat

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

Given the above, a type of heart drug called a calcium channel blocker might be able to eliminate the “noise” caused by this abnormal RNA, they reasoned.

These drugs have successfully relieved the symptoms of T1D in lab mice caused by a genetic problem that causes muscular dystrophy.According to the results, which were published in the January 2 issue of the Journal of Clinical Investigation.

“We believe that the calcium channel is a new therapeutic target and, if we can target it properly, pharmacologically, 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 use, they said in supporting notes.

Muscle problems caused by the disease affect the eyes, heart and brain, eventually leading to problems with walking, swallowing and breathing.

More than two decades ago, co-investigator Dr. Charles Thornton discovered how a genetic defect causes T1D. According to Thornton’s previous research, the genetic “stutter” results in thousands of code repeats in a segment of chromosome 19.

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

“Myotonic dystrophy is a really complex disorder that can almost be seen as an aggregate of many diseases,” co-investigator John Luke, an associate professor at the University of Rochester Medical Center, said in a University of Rochester news release.

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

Verapamil, a calcium channel blocker used to treat blood pressure and chest pain, caused the mice to quickly recover muscle function and appear as healthy as normal lab rats, the researchers reported.

“Our research also suggests that muscle damage in T1D is potentially reduced by commonly 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 humans with T1D, as it may have harmful side effects. Additionally, research in mice does not always work in humans.

“Our goal now is to find a suitable, safe calcium channel blocker that works, 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, news release, January 2, 2023