Fats, Eicosanoids, and fat processing enzymes.

[Guest guest]

The current discussions about fat and carbohydrate metabolism are very

important for our understanding of " Optimum Nutrition " . I just looked

up " Beef, Bottom Sirloin " (USDA SR-17 #13954) and found that 100g

contains 20.6g of protein, 8.5g of fat, and 0g carbohydrates (the

remainder is water). Our bodies probably have a similar composition.

The glycogen stores that are stored in our muscles are so miniscule

that they are neglegible. Our bodies are basically protein and fat.

This means that no matter what you eat, the protein in your food ends

up as muscle or peptide hormones, the carbs that you eat end up as fat

(unless they are burned right away), and the fat that you eat ends up

as fat or fat metabolites that include eicosanoids.

Eicosanoids are produced through the action of enzymes such as

cyclooxygenase and lypoxygenase. The eicosanoids include classes of

20-carbon compounds such as prostaglandins, prostacyclins,

thromboxanes, leukotrienes, and hydroxy fatty acids which have

powerful biochemical activities.

There are variants of CycloOXigenase, one of which is the COX-2 enzyme

which is inhibited by pain drugs such as Vioxx. As we have seen with

Vioxx, messing with the metabolism of fats can have serious health

consequences.

CR and Optimum Nutrition can probably help to prevent many of the

conditions that are treated by these drugs.

Tony

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An outline of the sythesis of prostagandins from arachidonic acid with

nice pictures of the molecules:

http://www.rndsystems.com/asp/g_sitebuilder.asp?bodyId=194

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http://www.jlr.org/cgi/content/abstract/41/10/1689

Journal of Lipid Research, Vol. 41, 1689-1694, October 2000

Eicosanoids as endogenous regulators of leptin release and lipolysis

by mouse adipose tissue in primary culture

N. Faina, W. Lefflerb, and Suleiman W. Bahouth

" These data indicate that PGE2 can stimulate leptin release and

suggest that endogenous eicosanoids affect both lipolysis and leptin

formation by mouse adipose tissue. "

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FASEB J. 1992 May;6(8):2530-6.

Biochemistry and physiology of n-3 fatty acids.

Lands WE.

Department of Biochemistry, University of Illinois, Chicago 60612.

Considering the n-3 fatty acids to be partial agonists relative to

n-6 fatty acids helps consolidate into a unified interpretation the

many diverse reports and controversies on the actions of these two

types of essential fatty acids. Some research reports illustrate the

similarities between these two types and some emphasize the

differences, leaving readers to evaluate the status of n-3 fatty acids

from a viewpoint that is conceptually similar to regarding a glass of

water as half empty or half full. Both n-3 and n-6 types of fatty

acids must be obtained through the diet because they are not

synthesized de novo by vertebrates. Both types can support important

physiological and developmental processes, can form eicosanoids

(prostaglandins, leukotrienes, lipoxins, etc.), can be esterified to

and hydrolyzed from tissue glycerolipids, and can be metabolically

elongated and desaturated to a variety of highly unsaturated fatty

acids. However, some nonesterified n-6 acids are vigorously converted

to potent n-6 eicosanoids that exert intense agonist actions at

eicosanoid receptors, whereas the n-3 acids less vigorously form n-3

eicosanoids that often produce less intense (partial) actions. Because

both types owe their presence in vertebrate tissues to dietary intake,

important physiological consequences follow the inadvertent selection

of different average daily dietary supplies of these two types of

polyunsaturated fatty acids.

PMID: 1592205

[Guest guest]

In Message 17828 I mentioned that the cyclooxygenase enzymes play an

important role in fat metabolism by producing eicosanoids. The

following report from has some related information.

Tony

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Oily Fish s Healthy Blood Fat

Mon Mar 7, 5:03 PM ET

MONDAY, March 7 (HealthDay News) -- For years, nutritionists have

known that eating oily fish like mackerel or salmon boosts human

health, although the exact reasons have remained unclear.

A new study may have solved that riddle.

Researchers say they've identified a powerful anti-inflammatory blood

fat in humans that's derived from omega-3 fatty acids sourced from

fish oil.

The lipid, called resolvin E1, was detected in plasma taken from study

volunteers who were given omega-3 fatty acids and aspirin, both of

which are used to lower inflammation.

Reporting in the March 7 issue of the Journal of Experimental

Medicine, the researchers believe resolvin E1 inhibits the migration

of inflammatory cells to sites of inflammation, and also curtails the

activity of other inflammatory cells.

This finding may help explain how a diet high in oily fish helps

reduce inflammation, particularly when used along with low doses of

aspirin, according to the investigators.

The information in this study also suggests potential problems with

cox-2 inhibitor drugs (which include Vioxx and Celebrex) that are

meant to block inflammation. These drugs have been shown to have

negative cardiovascular side effects.

The study authors noted that cox-2 plays a role in making resolvin E1.

They suggest that inhibition of vascular cox-2 by cox-2 inhibitor

drugs may block production of resolvin E1, thus eliminating an

important natural anti-inflammatory response. They stress, however,

that no research has yet been conducted to confirm this theory.