The amazing mitochondria and how they sustain you

MITOCHONDRIA ARE special compartments (organelles) in our cells that are best known for their role as powerhouses, as they break down food molecules and turn out adenosine triphosphate (ATP), a molecular fuel for the rest of the cell. However, they carry out many other important biological processes and are central to the correct functioning of the human cell.

Mitochondria are also involved in other tasks, such as signalling between cells and cell death, otherwise known as apoptosis. Mitochondria are surrounded by a double-membrane system, consisting of inner and outer mitochondrial membranes separated by an intermembrane space.

The inner membrane forms numerous folds (cristae), which extend into the interior (or matrix) of the organelle. Each of these components plays distinct functional roles, with the matrix and inner membrane representing the major working compartments of mitochondria.

According to Dr Clive Campbell, nearly all cells have these sausage-shaped structures, but muscle and nerve cells, which require more energy, have the highest concentrations of mitochondria, numbering in the thousands.

“Beyond their role as energy converters, scientists have also recently uncovered how mitochondria play other critical roles: They act as storage tanks for calcium ions, which are involved in blood clotting and muscle contraction; produce the iron compound needed for red blood cells to transport oxygen; and, last but not least, they are being studied as the lead “executioners” of cells, with the ability to trigger cell death,” Dr Campbell said.

He indicated that mitochondria have such an important job to do in helping cells function properly that when they malfunction, they can cause diseases. Some malfunctions are believed to be due to mutations of mitochondrial DNA in about 15 per cent of cases.

“Other times, mutations in genes will cause problems and lead to inherited diseases. It has been found that malfunctioning mitochondria play a role in conditions such as autism, heart failure, and cardiac dysfunction. People with Parkinson’s disease have a high level of mitochondrial mutations,” he said.

Mitochondrial disease can affect nearly all parts of the body, meaning there can be a wide range of symptoms. A person may experience milder or more severe symptoms. The symptoms a person experiences typically depend on the affected cells and whether some mitochondria are still working as they should.

The typical symptoms of many mitochondrial diseases are loss of muscle coordination, muscle weakness, sight problems, liver disease, kidney disease, neurological conditions, and gastrointestinal problems, to name just a few.

“Someone may experience symptoms in only one or many parts of the body. Some more general symptoms of mitochondrial disease include fatigue, headaches or migraine, reduced growth in children, learning delays and developmental problems, seizures, changes in or loss of hearing and vision, exercise intolerance and cardiomyopathy,” Dr Campbell said.

The treatment of mitochondrial disease varies considerably. Most experts use a combination of vitamins, optimise patients’ nutrition and general health, and prevent worsening of symptoms during times of illness and physiologic stress.

Treatment could include taking medications to reduce symptoms, like medications to prevent seizures; taking vitamins or supplements, like riboflavin, coenzyme Q10 and carnitine; changing your diet (nutrition) and exercising; or physical therapy, occupational therapy or speech therapy. You can also wear assistive devices like hearing aids.

There is no cure for mitochondrial disease. Treatment focuses on preventing life-threatening complications, and treatment that works for one person may differ from what works to treat someone else with the same condition.

“There is no known way to prevent mitochondrial diseases. If you have a mitochondrial disease, you can avoid situations that can make your symptoms worse, for example, exposure to extreme cold and/or heat, skipping meals, not getting enough sleep and stress,” Dr Campbell said.

Your doctor may suggest you conserve your energy to avoid using up all of your body’s energy in a short period of time.

keisha.hill@gleanerjm.com

SOURCE: Health Talk Sunday