Friday, March 04, 2005

Asthenic Sperm

Continuing my international theme, here's an article for the boys, from the Italians:

Taking carnitine supplements seems to improve sperm mobility in men with poorly active sperm, a problem known as asthenozoospermia, Italian researchers report.

However, for carnitine to work, tiny structures within the cell called mitochondria must function properly. Mitochondria are important because they provide the energy needed for sperm to move their tail and "swim."

...

In patients with normal mitochondria function, movement rose from 29.3 percent before treatment to 41.1 percent after 3 months of carnitine. However, in those with abnormal function, movement held steady at about 24 percent.


And here's everything you ever wanted to know about carnitine and mitochondria, but were afraid to ask [definitional links in the text mine]:

Carnitine

A naturally occurring hydrophilic amino acid derivative, produced endogenously in the kidneys and liver and derived from meat and dairy products in the diet. It plays an essential role in the transfer of long-chain fatty acids into the mitochondria for beta-oxidation. Carnitine binds acyl residues and helps in their elimination, decreasing the number of acyl residues conjugated with coenzyme A (CoA) and increasing the ratio between free and acylated CoA.

Carnitine deficiency is a metabolic state in which carnitine concentrations in plasma and tissues are less than the levels required for normal function of the organism. Biologic effects of low carnitine levels may not be clinically significant until they reach less than 10-20% of normal. Carnitine deficiency may be primary or secondary.


Mitochondria



Mitochondria are the cells' power sources. They are distinct organelles with two membranes. Usually they are rod-shaped, however they can be round. The outer membrane limits the organelle. The inner membrane is thrown into folds or shelves that project inward. These are called "cristae mitochondriales".

The food we eat is oxidized to produce high-energy electrons that are converted to stored energy. This energy is stored in high energy phosphate bonds in a molecule called adenosine triphosphate, or ATP.

The food we eat must first be converted to basic chemicals that the cell can use. Some of the best energy supplying foods contain sugars or carbohydrates ...bread, for example. Using this as an example, the sugars are broken down by enzymes that split them into the simplest form of sugar which is called glucose. Then, glucose enters the cell by special molecules in the membrane called "glucose transporters".

Once inside the cell, glucose is broken down to make ATP in two pathways. The first pathway requires no oxygen and is called anaerobic metabolism. This pathway is called glycolysis and it occurs in the cytoplasm outside the mitochondria. During glycolysis, glucose is broken down into pyruvate. Other foods like fats can also be broken down for use as fuel.... Each reaction is designed to produce some hydrogen ions (electrons) that can be used to make energy packets (ATP). However, only 4 ATP molecules can be made by one molecule of glucose run through this pathway. That is why mitochondria and oxygen are so important. We need to continue the breakdown process with the Kreb's cycle inside the mitochondria in order to get enough ATP to run all the cell functions.

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