P5P

9-18-2021 links: reference:

Pyridoxal 5’-Phosphate (P5P) (PLP) #

The active form of B6.

• Prolactin inhibitor. Exerts hypothalamic dopaminergic effect.

• Enhances MAO-A. RPF

• A 5-AR inhibitor, while pyridoxine hcl is an enhancer? This guy gets irritation, anxiety, and breathlessness from 12.5mg (which apparently acts more like 60mg of b6). RPF

• Vitamin D receptor antagonist?

https://raypeatforum.com/community/threads/pyridoxine-vs-p5p.30429/post-461714 - “Alkaline phosphatase, a zinc-dependent enzyme, hydrolyzes the phosphate from the phosphorylated vitamers to yield free Pyridoxine (PN), Pyridoxal (PL), or Pyridoxamine (PM)” - “When the phosphorylated vitamers are ingested in high concentrations, some of these compounds may be absorbed without dephosphorylation” (Usually in hepatocyte cytosol) - “Intracellular P5P concentrations are dependent, in part, upon the availability of binding proteins. With saturation of binding proteins, unbound PLP is hydrolyzed to PL, which is released into the blood for use by other tissues. From the liver, mostly PLP and PL, with smaller amounts of the other vitamers, are released into the blood for transport to extrahepatic tissues.” - Most P5P in blood is bound to Albumin. Muscles represent 75-80% of the storage for B6, mainly as P5P bound to Glycogen phosphorylase.

• Disorders affecting vitamin B6 metabolism
  • Because of the reactivity of its Aldehyde group, PLP can undergo reactions analogous to those of ROS. Reactions of PLP with amino groups of proteins can alter their structure[5] and at concentrations of 10 to 100 μM inhibit enzyme activity[6] and aldehydes can damage DNA leading to mutagenesis.
  • PLP can also react with small molecules such as sulphydrl compounds such as cysteine, resulting in the formation of thiazoliodines, and with sulfite producing a sulphonate.
  • Hence, the cell maintains intracellular levels of free PLP at approximately 1 μM to avoid any unwanted reactions occuring.
  • The intestine only absorbs nonphosphorylated B6 vitamers. The phosphorylated forms of B6 and the glucoside of pyridoxine are therefore first hydrolyzed by intestinal Phosphatases and an intestinal glycosidase, respectively. They are then (again) rephosphorylated by pyridoxal kinase.
  • For PLP to enter the brain, it must dissociate from albumin and be dephosphorylated to Pyridoxal at the BBB via alkaline phosphatase, which is tethered to cell membranes by glycophosphatidylinositol.

Supplementation #

• Builds up in your body, so it doesn’t require daily use. Intake @ 1 dose might be low, though.
• 10-25mg; 50 max.
• In Cardenosine (40 drops; 15 servings; distilled water):
  • Adenosine Triphosphate (ATP): 200mg
  • Succinic acid: 200mg
  • L-Pyroglutamic acid: 200mg
  • Inosine: 100mg
  • Vitamin B6 (P5P): 10mg