August 13, 2012
The more energy the cell needs, the more mitochondria it contains. One cell can have anywhere from a few mitochondria up to thousands. The highest numbers are found in nerve, muscle, and liver cells.
Some scientists believe that mitochondria are the key to aging. As we grow older, our mitochondria collect more and more mutations. Our cells have a way to check for mistakes (mutations) when they multiply, but mitochondria don't.
Lactic acid can cause sore muscles. For example, the soreness people feel after running a marathon is caused by a buildup of lactic acid.
Some people with MT have very high levels of lactic acid in their blood. This rare condition is called lactic acidosis. There is a blood test for lactic acid levels, but experts disagree on how to interpret the results. Physical exertion before the blood test -- including climbing stairs or walking quickly -- can increase lactic acid levels and throw off the test results.
It's difficult to know if you have MT. However, you can look for the following signs of lactic acidosis:
MT may also cause nerve damage (peripheral neuropathy, see Fact Sheet 555). It has been linked to kidney damage and hearing loss. Some researchers believe it might also contribute to fat redistribution (lipodystrophy, see Fact Sheet 553) in people taking antiretroviral medications (ARVs).
Different medications build up in different parts of the body. This could explain how MT caused by different drugs can lead to side effects in different parts of the body.
We know that MT can cause muscle weakness in people taking AZT. It is probably the cause of "fatty liver" (hepatic steatosis) and high levels of lactic acid that can be caused by all of the nukes. Unfortunately, there is very little research on how much mitochondrial damage each ARV causes to different parts of the body. We also don't know which combinations of drugs cause the most MT.
Researchers know how to measure the number of mitochondria in different cells, compared to normal. However, they don't know many mitochondria a cell can lose before there are problems.
Over the next few years, researchers will study MT. They will work on tests to identify it. They will also study the link between MT and various side effects. Some researchers believe that certain vitamins and minerals can help mitochondria overcome the effects of ARVs.
In the meantime, people with HIV need to know the symptoms of lactic acidosis, a rare side effect that can be fatal.
This article was provided by AIDS InfoNet. Visit AIDS InfoNet's website to find out more about their activities and publications.