Cholesterol
hideCholesterol is a lipidic, waxy steroid found in the cell membranes and transported in the blood plasma of all animals. It is an essential component of mammalian cell membranes where it is required to establish proper membrane permeability and fluidity. Cholesterol is the principal sterol synthesized by animals, but small quantities are synthesized in other eukaryotes, such as plants and fungi. It is almost completely absent among prokaryotes, which include bacteria. Cholesterol is classified as a sterol.
Since cholesterol is essential for life, it is primarily synthesized de novo within the body. However excessive levels of cholesterol in blood circulation are strongly associated with progression of atherosclerosis. For an adult, typical total body cholesterol synthesis is about 1 gram per day (less if dietary intake is high) and total body cholesterol content is about 35 g. Average dietary intake in western societies is 0.2 - 0.3 grams. Cholesterol is excreted by the liver via the bile into the digestive tract. Typically about 50% of the excreted cholesterol is reabsorbed by the small bowel back into the blood stream.
The name cholesterol originates from the Greek chole- (bile) and stereos (solid), and the chemical suffix -ol for an alcohol, as François Poulletier de la Salle first identified cholesterol in solid form in gallstones, in 1769. However, it was only in 1815 that chemist Eugène Chevreul named the compound "cholesterine".
For more information about Cholesterol, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with cholesterol
Why we outlive our ape ancestors
Dec 02, 2009 |
4 / 5 (5) |
0
In spite of their genetic similarity to humans, chimpanzees and great apes have maximum lifespans that rarely exceed 50 years. The difference, explains USC Davis School of Gerontology Professor Caleb Finch, is that as humans ...
Latest epidemic? High cholesterol, obesity in fruit flies
Dec 02, 2009 |
4 / 5 (1) |
0
How do fruit flies get high cholesterol and become obese? The same way as people do - by eating a diet that's too rich in fats.
Free e-samples of prescription drugs: At what cost?
Nov 25, 2009 |
5 / 5 (1) |
0
Search the Internet to learn about your asthma, high cholesterol or other common disorder, and odds are you'll be directed to a pharmaceutical company-sponsored Web homepage. There you'll often find an offer for a free sample ...
Feeding the clock: Cycles of feeding and fasting drive circadian gene expression in the liver
Nov 25, 2009 |
4.5 / 5 (4) |
0
When you eat may be just as vital to your health as what you eat, found researchers at the Salk Institute for Biological Studies. Their experiments in mice revealed that the daily waxing and waning of thousands ...
New data emerges on liver transplant survival rates
Nov 25, 2009 |
not rated yet |
0
Researchers at the University of Miami School of Medicine compared the outcomes of cirrhotic patients who underwent liver transplants for nonalcoholic steatohepatitis (NASH) versus alcoholic liver disease (ETOH) and found ...
Abnormal cholesterol levels may raise risk of heart failure
Nov 23, 2009 |
5 / 5 (1) |
0
(PhysOrg.com) -- Even if you never have a heart attack, abnormal blood cholesterol levels may significantly raise your risk of heart failure, according to research reported in Circulation: Journal of the American Heart As ...
Vitamin B niacin offers no extra benefit to statin therapy in seniors already diagnosed with CAD
Nov 18, 2009 |
5 / 5 (2) |
0
The routine prescription of extended-release niacin, a B vitamin (1,500 milligrams daily), in combination with traditional cholesterol-lowering therapy offers no extra benefit in correcting arterial narrowing and diminishing ...
The protein Srebp2 drives cholesterol formation in prion-infected neuronal cells
Nov 18, 2009 |
4 / 5 (1) |
0
Prions are causing fatal and infectious diseases of the nervous system, such as the mad cow disease (BSE), scrapie in sheep or Creutzfeldt-Jakob disease in humans. Scientists of Helmholtz Zentrum München and Technische Universität ...
Prevalence of high LDL, or 'bad' cholesterol levels decreases in US
Nov 17, 2009 |
5 / 5 (1) |
0
Between 1999 and 2006, the prevalence of adults in the U.S. with high levels of LDL cholesterol, the "bad" cholesterol, decreased by about one-third, according to a study in the November 18 issue of JAMA. But a high percen ...
Some obese people perceive body size as OK, dismiss need to lose weight
Nov 17, 2009 |
5 / 5 (1) |
0
Some obese people misperceive that their body size is normal and think they don't need to lose weight, according to research presented at the American Heart Association's Scientific Sessions 2009.
Fungi May Hold Key to Reducing Grapefruit Juice Interactions with Medications
Nov 17, 2009 |
5 / 5 (1) |
1
(PhysOrg.com) -- A fungus may help solve a problem of a grapefruit compound that interacts negatively with certain prescription drugs, according to studies by Agricultural Research Service (ARS) scientists.
Early end to key study on benefits of niacin, a B vitamin, in keeping arteries open was premature
Nov 16, 2009 |
3.7 / 5 (3) |
0
Heart experts at Johns Hopkins are calling premature the early halt of a study by researchers at Walter Reed Army Medical Center and Washington Hospital Center on the benefits of combining extended-release niacin, a B vitamin, ...
Study raises new questions about Merck pill Zetia
Medicine & Health / Medications
Nov 16, 2009 |
5 / 5 (3) |
1
(AP) -- A new study raises fresh concerns about Zetia and its cousin, Vytorin - drugs still taken by millions of Americans to lower cholesterol, despite questions raised last year about how well they work.
No need to fast for cholesterol test
Nov 13, 2009 |
5 / 5 (8) |
1
(PhysOrg.com) -- Patients do not need to fast before having their cholesterol tested, a major study has found.
Role of Statins in Reducing H1N1 Mortality Rates Studied
Nov 13, 2009 |
not rated yet |
0
(PhysOrg.com) -- Vanderbilt University Medical Center researchers are studying statins, the class of drugs long associated with lowering cholesterol, as a way to reduce H1N1-related deaths.
