Jarrow Formulas Arginine-citrulline Sustain™ supports Nitric Oxide production and enhances blood flow.
what does Arginine-Citrulline Sustain do?
Jarrow Formulas Arginine-Citrulline Sustain is a synergistic combination of two amino acids to support nitric oxide (NO) production, blood flow and cardiovascular health.
L-Citrulline largely converts to L-Arginine, increasing circulating and blood vessel levels of L-Arginine for NO production.
Arginine-Citrulline Sustain provides these amino acids to the body over an 8 hour period.
• reduces muscle fatigue
• increases nitrogen oxide (NO) which leads to vasodilation and results into the famous 'pump'
• a higher NO production also results in higher muscle synthesis as NO also stimulates formation of muscle protein
The amino acid L-arginine is required for the enzymatic synthesis of the messenger molecule nitric oxide (NO) in the body. The vascular endothelium is a single layer of cells between the blood vessel lumen and underlying vascular smooth muscle cells. NO produced by vascular endothelial cells is essential for the proper function of blood vessels and maintenance of cardiovascular health.
Nitric Oxide & vascular function
Once synthesized, NO diffuses across the endothelial cell membrane and enters the vascular smooth muscle cells to modulate tone (constriction/dilation). NO is a potent vasodilator, allowing blood vessels to relax and widen to enhance blood flow. The balance between NO and various endothelium-derived vasoconstrictors and the sympathetic nervous system maintains blood vessel tone. NO also suppresses platelet aggregation (blood clotting), immune cell adhesion to the blood vessel surface, vascular permeability, and blunts vascular smooth muscle cell migration and proliferation.
NO bioactivity is determined by the balance between its synthesis and degradation. Reduced NO bioactivity due to diminished production and/or enhanced degradation manifests as impaired endotheliumdependent vasodilation (endothelial dysfunction). Endothelial nitric oxide synthase (eNOS), the endothelial isoform of the enzyme, utilizes the amino acid L-arginine and molecular oxygen to produce NO in the process giving rise to a related amino acid, L-citrulline, as a byproduct.
Research indicates endothelial dysfunction results from selective impairment of the L-arginine-NO pathway with endothelial dysfunction rather than from reduced responsiveness of vascular smooth muscle cells to NO signaling.
Oral arginine limitations
Oral L-arginine bioavailability to support endothelial NO synthesis is low due to extensive metabolism to urea by the enzyme arginase in the intestines and liver (~80%). Arginase competes with eNOS for their common substrate arginine. High levels of circulating L-arginine induce arginase activity in the liver, kidney, and vasculature, which increases arginine degradation. Even though most ingested L-arginine is metabolized in the intestines and liver, levels that reach systemic circulation are sufficient to augment vascular arginase activity to limit availability for endothelial NO production. Levels and activity of arginase are increased with aging and various conditions characterized by oxidative stress and impaired vascular function.
L-citrulline is an important substitute for L-arginine under certain physiologic conditions that limit L-arginine availability as it because citrulline serves as substrate for de novo synthesis of L-arginine in mammals. Oral supplementation with L-citrulline is more effective than L-arginine in raising blood arginine levels because it largely bypasses metabolism in the gut and liver. Unlike L-arginine, L-citrulline is not a substrate for, nor does it induce, arginase activity, so exhibits remarkably high systemic bioavailability. Ingested L-citrulline is primarily metabolized to L-arginine by the kidney, releasing arginine equivalent to ~75% of the L-citrulline taken up.
Endothelial cells can also convert L-citrulline back to L-arginine to provide the requisite substrate for NO production.
Oral citrulline supplementation has been shown to dose-dependently raise blood arginine levels in healthy adults more efficiently than equivalent doses of arginine. Of note, citrulline is scarce in the diet, with the only notable source, watermelon, providing 0.7 – 3.6 mg per gram. Thus, levels consumed naturally through the diet without supplementation may be too low to significantly increase blood arginine levels.
Recent scientific evidence has shown the combination of arginine and citrulline in a 1:1 ratio more rapidly and effectively increases blood levels of L-arginine compared to either individual amino acid ingested alone (2, 3). L-citrulline suppresses arginase activity, acting as a noncompetitive (allosteric) inhibitor, so is anticipated to spare arginine from first-pass metabolism in the intestines and liver to make oral L-arginine more available to the vascular endothelium to support NO production.
Additionally, the utilization of oral arginine for NO synthesis was higher with a sustained- compared to an immediate-release L-arginine preparation in people with endothelial dysfunction, despite similar blood levels of arginine. A slow arginine absorption rate may limit activation of the metabolic disposal of arginine to favor its use in other metabolic pathways, including eNOS-mediated NO synthesis.
Oxidative stress & Nitric Oxide bioactivity
Oxidative stress reduces NO bioactivity, so is causally linked to impaired vascular function. Tetrahydrobiopterin (BH4) is an essential eNOS cofactor required for NO synthesis. In its active, reduced form, BH4 is highly susceptible to oxidation. Diminished BH4 availability compromises eNOS function by promoting electron transfer to molecular oxygen instead of L-arginine to generate superoxide radical (O2−) instead of NO. This phenomenon is commonly referred to as “eNOS uncoupling.” Uncoupled eNOS may initiate a vicious feedforward cycle to propagate oxidative stress that further increases oxidative degradation of NO and BH4, progressive eNOS uncoupling, and impaired vascular function. BH4 deficiency plays a major role in impaired vascular function.
Vitamin C to the rescue
Antioxidant vitamin C discourages eNOS uncoupling under conditions of oxidative stress by stabilizing BH4. Supplementation with vitamin C has been shown to prevent oxidation of BH4 and thereby to facilitate eNOS-derived NO production. Evidence also suggests that vitamin C enhances eNOS activity independent of BH4 stabilization through alterations in eNOS phosphorylation that increase enzymatic activity
Some supplements are suitable for both men and women of all ages as well as children. But other supplements are specifically targeted to the aging woman or man. Another supplement is especially suitable for athletes, regardless of gender.
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- keep out of reach of young children
- a dietary supplement is not a subsitute for a healthy diet ; do not exceed recommended dose
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Tips and tricks to keep your house cool without airconditioning
After having survived the hottest two weeks of the past century, and hearing about the deliberate choice to switch of the power in some areas of California as it became impossible to match the demand for electricity, due to the massive use of airconditioning, this week's topic had to be about how to keep your house and yourself cool without needing to rely on energy-guzzling airconditioning.
How to make better food and lifestyle choices
Everything really started with an advertisement in an American muscle magazine with the name MM2K (Muscle Media 2000) for a product called DHEA
At the time, MM2K was a revolutionary magazine because they didn't tell you lies about doping use in sports and bodybuilding and strength sports in particular, unlike other magazines that were solely focused on inspirational stories and faking how bodyubuilding was a doping-free sports.
By contrast, MM2K wrote openly about doping, supplements, nutrition, training, and other gossip stories about health, sports and politics.
MM2K had great contributing authors, such as Bill Philips himself, Dan Duchaine who was seen as the 'mad scientist' and Charles Poliquin, a well-respected personal trainer. Dan Duchaine wrote extensively about diet drugs, which he wrote down in his booklet 'Dirty Dieting', which would become the starting point for more diet books written by Lyle McDonald.
Can training with just weight machines make you stronger?
Whomever has been a member of a gym in the past 15 years, will have noticed how slowly but surely, machines have taken a back seat and more and more space is given to 3-dimensional weight equipment, like suspension (TRX-)trainers, gym balls, kettle bells and even fun stuff that was formerly unheard of like pole dances and climbing walls.
A very popular trend is the development of Cross-Fit in which both strength and endurance is equally valued and in which Olympic weightlifting exercises are also incorporated.
As someone who has dabbled both in Olympic and power lifting as well as endurance cycling, I've been very happy about this development even though I keep using machines myself too. Recently, Christian Finn, a coach who specialized in rehab training, pointed out how machines have a more important role than most of us realize. It's well worth sharing it in our blog, too.
How to make a habit out of good intentions
Sometimes you stumble on articles, that are too good to pass up on. For those who have started the year with good intentions, we are sharing an article on how to make a habit out of good intentions. It's written by a guy who changed his habits after he became a father and wanted to be a good parent by setting an example.
“Your net worth to the world is usually determined by what remains after your bad habits are subtracted from your good ones.”
You probably agree with that statement.
But, for you (and everyone else) the problem is that good habits are hard to form and bad habits are easy to keep.
It is certainly true for me. Like most of us, I meant to start exercising for about six years after I started my career.
But it never happened. I’d do it for two or three weeks here and there, but nothing that ever stuck.
Then, all of a sudden, it did.
And it did because something changed for me. I had a son that was old enough to mimic me and that I wanted to be able to keep up with for the next twenty years. That scared me straight essentially.
In a number of areas in my life, including fitness, I realized he was going to base a significant portion of his view of how to live life and what habits were important off of what he watched me do.
So I stopped acting like I was going start exercising and I actually did it.
To create my new habit, I used a combination of the techniques below. You can use them to firm up your new habit and get your good habit quotient up.
Keto diets for endurance athletesMany of us will have heard of the advantages of very low carb diets for obese patients and more specifically for diabetics. Going very low carb results in not having as much hunger and much healthier blood glucose levels. Another group that often goes on a keto diet are those who want to prevent tumour growth.
Don't sabotage your virility!
Plasticizers are additives of which phtalates are the most abundant ones (and bisphenol-A or BPA the best known) that are used to increase the flexibility or plasticity of the material to which they are added, normally rigid plastic and as additives in paint and adhesives.
Phtalates are not just found in obvious plastic packaging, building materials and toys, but also in fragrances, cosmetics, shampoo, shaving cream, and other cleaning detergents.
Blood flow and vasodilationVasodilation is the process by which the blood vessels in the body relax and widen, allowing for greater blood flow. One of the main triggers of vasodilation is nitric oxide (NO).
Therefore, anything that increases nitric oxide production in the body will also increase vasodilation.
Wat is citrulline?Citrulline dat verkwikkend werkt op de spieren, lichamelijk welbevinden en dus op het prestatievermogen. Citrulline is zowel een precursor voor de essentiële aminozuren arginine en ornithine en daardoor een precursor voor stikstof (NO), wat inwerkt op zowel de geslachtsorganen als op die spieren, waar het helpt bij de afvoer van melkzuur en de spieren gevoeliger maakt voor het spieropbouwende / spierherstellende hormoon testosteron.
take 2 tablets 1 to 2 times per day on an empty stomach prior to meals or as directed by your qualified healht care professional
contains per daily serving (2 tablets)
vitamin C (as calcium ascorbate) 10mg 10% RDI
L-arginine (as L-arginine HCl) 500mg †
L-citrulline (free form) 500mg †
† = Recommended Daily Intake not established
active ingredient (L-arginine, L-citrulline, calcium ascorbate), filler (cellulose), anticoagulant (silicon dioxide), filler (vegetable magnesium stearate), food-grade coating
keep dry and closed at normal room temperature
keep out of reach of young children
If you have a medical condition (especially hypotension or herpes), are pregnant, lactating, trying to conceive, under the age of 18, or taking medications, consult your health care practitioner before using this product.
contains no familiar allergens (wheat, gluten, soy, lupin, nuts, tree nuts, celery, mustard, sesame seeds, dairy, egg, fish/shellfish or mollusks)
suitable for vegetarians and vegans