Vitamin Glossary "M"

• macrophage- cells that have the ability to recognize and ingest all foreign antigens as well as cell debris and other waste in the blood.

   

• macule- the central area of the retina.

   

• malonaldehyde- an aldehyde formed as a breakdown product of peroxidized polyunsaturated lipids in the body. Malonaldehyde is a mutagen, carcinogen, and cross-linker.

   

• melanoma- a type of often deadly skin cancer.

   

• membrane stabilizers- compounds which can protect cellular membranes from damage. Some examples are vitamin E, PABA, inositol and hydrocortisone.

   

• meninges- the three membranes covering the brain and the spinal cord.

   

• meridian- the fourteen channels in the body through which qi runs. Acupuncture diagnoses illness by seeking blockages in the body's meridians.

   

• metabolism- the transformation in the body of the chemical energy of foodstuffs to mechanical energy or heat.

   

• metastasis- the spreading of a tumor from its site of origin to distant sites, usually through the bloodstream or the lymphatic system.

   

• membrane stabilizers- compounds which can protect cellular membranes from damage. Some examples are vitamin E, PABA, inositol and hydrocortisone.

   

• methionine- a sulfur-bearing compound, an essential amino acid.

   

• mitochondria- structures in cells that act as power plants. Mitochondria oxidize food to water, carbon dioxide, and energy. This energy is used by the mitochondria to convert low energy ADP (adenosine diphosphate) to high energy ATP (adenosine triphosphate), the cell's universal energy molecule. Free radicals are a normal and essential part of mitochondrial oxidation, but dangerous if the escape from the protective control systems in the mitochondria.

   

• mixed function oxidase-an enzyme system in the liver mitochondria (and to lesser extent in mitochondria in other cells) which detoxifies many poisons by altering them chemically. Some foods, such as brussels sprouts, activate this system.

   

• monamine oxidase (MAO)-an enzyme which, in the brain, degrades certain neurotransmitters (such as serotonin, dopamine and nor- epinephrine). In aging brains, these neurotransmitters may decline in concentration or receptors may be lost or develop insensitivity to them. Monamine oxidase inhibitors are sometimes used as anti- depressants. By reducing the degradation of neurotransmitters, their concentrations can be increased. Examples of monamine oxidase (MAO) inhibitors are isocarboxazid, phenelzine, and tranyl- cyrpomine.

   

• monounsaturated fat-a fat which contains a single carbon to carbon double bond. This double bond can react more readily with oxygen in a free radical reaction than the single bonds. Most monounsatu-rated fats are more similar to saturated fats than polyunsaturated fats in their ease of free radical autoxidation (the process that causes rancidity.)

   

• mucosa- a mucous membrane or the moist tissue layer that lines a hollow organ or body cavity.

   

• musculoskeletal system- pertaining to the muscles and the skeleton.

   

• mutagen- a chemical which causes alterations in DNA structure, usually resulting in faulty cell function and sometimes in cancer.

   

• myocardiopathy- any disease of the heart muscle.

   

• myelin- a fatlike substance forming a sheath around the axons, or nerve fibers, of certain nerves.