Getting the heart pumping with a little exercise is good for the body—it lowers blood pressure and helps fight off heart disease. That makes getting fit a popular New Year’s resolution, but still no one really understands the molecular mechanism that’s behind the scenes. Now, reports show that exercise’s benefits may be due to its effects on certain miRNAs.
Researchers in Brazil and California reasoned that if miRNAs were involved, it would likely be some of the usual suspects like miRNA-16, -21, and -126, which have roles in angiogenesis. So, they looked at levels of those miRNAs in normal rats and those with high blood pressure (hypertensive rats), with and without 10 weeks of exercise training. Here’s what they found:
- Exercise lowered the systolic blood pressure (the top number of a blood pressure reading) in hypertensive rats. It also lowered the heart rate of both the normal and hypertensive rats.
- Exercise also increased the density of blood vessels in both groups’ muscles.
- Hypertensive rats had more miRNA-16 and -21 than normal rats, but exercise reduced these levels to the normal range.
- Hypertensive rats had less miRNA-126 than normal rats, but, again, exercise brought these levels back to the normal range.
- Angiogenesis correlated with the miRNAs getting back to normal levels.
- Exercise also increased levels of known angiogenic factors and decreased levels of apoptotic factors in hypertensive rats.
The results suggest that miRNA-16, -21, and -126 might be missing links that explain how exercise lowers blood pressure. Therefore, they say that these miRNAs could be useful therapeutic targets for treating hypertension.
Before you go hit the treadmill, check out all the details at Hypertension, January 2012.