Yes exactly, the NAD+ ase make it release Nam that will in turn shut down SIRT. But we cant do anything against it, only solution is to keep your NAD+/NADH level very positive as its the case in young mamals. this will also control your weight and you will avoid for instance the adipose white tissue Nicotinamide N-methyltransferase (NNMT) rich that does the following: http://www.ncbi.nlm....pubmed/18996527 These data support the concept that adipose tissue NNMT contributes to the increased plasma homocysteine levels in patients treated with NA.
according to this paper in nature: http://www.nature.co...bs/nm.3882.html :
"Nicotinamide N-methyltransferase (Nnmt) methylates nicotinamide, a form of vitamin B3, to produce N1-methylnicotinamide (MNAM)." but note that Nnmt in liver seems to have different effect than the one in white adipose tissue
NR will release also directly Nam using a certain pathway. When I say all B3s it include also NR of course, since it even if it was not directly tested for homocysteine, its Nam metabolite will for sure:
http://www.ncbi.nlm....pubmed/23768418
Nicotinamide (Nam) supplementation increased the plasma levels of nicotinamide, N1-methylnicotinamide and choline and decreased the levels of betaine, which is associated with a decrease in global hepatic DNA methylation and uracil content in DNA. Nicotinamide had gene-specific effects on the methylation of CpG sites within the promoters and the expression of hepatic genes tested that are responsible for methyl transfer reactions (nicotinamide N-methyltransferase and DNA methyltransferase 1), for homocysteine metabolism (betaine-homocysteine S-methyltransferase, methionine synthase and cystathionine β-synthase) and for oxidative defence (catalase and tumour protein p53). It is concluded that nicotinamide-induced oxidative tissue injury, insulin resistance and disturbed methyl metabolism can lead to epigenetic changes. The present study suggests that long-term high nicotinamide intake (e.g. induced by niacin fortification) may be a risk factor for methylation- and insulin resistance-related metabolic abnormalities.
EDIT: oh and when I say "it's not that easy" its because here as you can see we do not target one specific tissue such as muscle using intramuscular injection. We speak about a precursor taken orally that involve much more pathway and has to target different tissue and face with Nampt leakage for instance. But same concern will happen if you use NMN orally
Edited by Tom Andre F. (ex shinobi), 28 June 2016 - 08:39 PM.