Simply put, L-norvaline can extend or prolong the activity of L-arginine and other precursor metabolites (spare parts) that promote nitric oxide production. In fact, studies conducted at the Department of Medical Physiology and Microcirculation at Texas A&M University, researchers reported that L-norvaline by inhibiting arginase activity increased nitric oxide production by 55%.  These researchers concluded that this regulatory mechanism of L-norvaline could be very important to nitric oxide synthesis, especially when the cellular supply of L-arginine starts to get low. 

Conversely, L-arginine can be metabolized (broken down) by arginase which also induces and increase production of L-ornithine and urea. However, when L-norvaline was introduced during heightened arginase activity, researchers at the University of New Mexico’s Vascular Physiology Group found that nitric oxide production increased with decreased urea production by 50%.  Why it this important?  Well, although L-ornithine is important to the formation of urea, basically urea is a waste product and is something you want to minimize the proliferation of.  The more this cycle (urea) dominates as a result of arginase activity, the more ammonia and other muscle wasting by products and cell toxicity occurs, lean tissue development and repair declines. 

The other side of this axiom in reference to the increased production of the amino acid L-ornithine is the comparable identical structure and function of L-arginine. L-ornithine like arginine promotes growth hormone production, body fat reduction and minimizes muscle fatigue. In practical terms here data suggest that L-norvaline intercedes and shifts the catabolic urea cycle to a growth or restorative phase by enhancing the production of L-ornithine, as well as regulating it’s  production of urea.  
                                                            
Lastly, present data confirms that high glucose levels increase arginase activity, by disrupting proper cellular communications.  This process is inhibited by L-norvaline, as it accelerates amino acid and glucose transport in both endothelial ( cells which line the interior surface of blood vessel )) and smooth muscle tissue. Essentially , L-norvaline intercedes and squashes cellular smoke signals that increase arginase activity, by literally moving glucose into tissues, thus improving its synthesis and supplying additional fuel to your hard earned muscle tissue.

Last Words

L-norvaline is a very concise example of how the presence of the right nutrient at the right time exudes it’s anabolic authority. It appears that it is faster than a speeding bullet, smarter than untruthful corrupt cellular communication systems and is able to leap towering catabolic roadblocks with ease. There appears to be no half stepping in L-norvaline’s quest to preserve muscle tissue and the correct physiologic anabolic way to build and preserve it!