Maximizing Arachidonic Acid delivery to skeletal muscle
I made a cursory glance into the X-Factor thread and I didn't see any suggestion on [b]when[/b] to take X-Factor, or other Arachidonic acid products, so here is [b]my[/b] suggestion.
[u][b]Background[/b][/u]
After ingestion, fatty acids like arachidonic acid are emulsifed and taken up into enterocytes where they are esterfied on a glycerol backbone to form a triglyceride. Next, the triglycerides and cholesterol esters are bound together to form a chylomicron. This entity can now diffuse into the lymphatics and then into the blood. Once in the blood, the chylomicrons are free to interact with various tissue receptors depending on energy homeostasis. When needed, they can interact with an enzyme called Lipoprotein Lipase (LPL) that will hydrolyze the triglycerides back into fatty acids to be used as fuel or for storage purposes.
[b][u]The [u]point[/u] being...[/u][/b]
In [i]which[/i] tissue the fatty acids are deposited is a function of the energetic state of the organism overall. In a post-prandial, high fed, state, the dominant hormone is insulin. Similarly, the only isoform of LPL that is active with insulin is located on adipocytes. It should be obvious now that consuming fats when eating will direct them to adipose. This isn't necessarily a bad thing in the context of fish oil, as adipose is now recognized as a great contributer to endogenous hormone production like the prostanoids.
[u][b]But...[/u][/b]
In the context of Arachidonic Acid, the final destination should be [i]skeletal muscle[/i]. Luckily, there is an energetic state which favors fatty acid delievery to this tissue: Exercise (or acute starvation) [1]. In an exercise-induced environment, LPL on skeletal muscle becomes active which serves as an adjunct to glycolysis for the TCA cycle via beta-oxidation. Similarly, the enzyme DGAT also becomes active in skeletal muscle which functions to store excess fatty acids as triglycerides. Since [b]both[/b] of these enzymes are heavily active during exercise, it is clear that an excess of fatty acids are being removed from blood plasma into skeletal muscle as a reservoir (this also serves to decrease insulin insensitivity [2]).
[u][b]Based on these observations[/b][/u]
To maximize ArA supplemention it is advisable to supplement 30-40 minutes prior to exercise in order to ensure plasma delievery of ArA and also to reduce exercises effects on gastric motility.
[1] [url]http://ajpendo.physiology.org/cgi/content/abstract/268/2/E229[/url]
[2] [url]http://ajpendo.physiology.org/cgi/content/abstract/294/5/E882[/url]
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-neuron
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