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a few questions about BH4

aaron_c

Senior Member
Messages
691
Hi Yall,

A discussion on this thread started veering into BH4 territory, so I thought I'd move it over here. I hope yall don't mind, but I do think it might be partinent.

If the B2 was helping me make nitric oxide, I would have felt better, not worse. I assume, then, that I'm missing a co-factor, which could be T4, or B3, or both, or....

You would be correct about NOS if it mostly operates in the direction you have indicated. Some people (Amy Yasko at least, and really anyone who buys that excessive ammonia can cause a depletion of BH4) believe that at least for people with our diseases, excessive ammonia can cause NOS to run in the opposite direction more often than it normally would, and that when it does so, it somehow uses up BH4. As I said, I at least do not know the mechanism, however, I have used BH4 to alleviate, in a dose-dependent manner, symptoms that would seem to have come from excessive ammonia. Perhaps after so many cycles BH4 becomes BH2, like methylcobalamin in methionine synthase, and the issue is simply that our excessive ammonia is using the enzyme much more than it would have otherwise been used? Here is a link to a longer explanation of my experiences with BH4, if you are interested.

Low MeB12, means poorer folate cycling. This leads to lower amounts of BH4 (an essential requirement for NOS).

In terms of folates being involved in the recycling of BH2 to BH4, here is an excellent explanation of how that happens (or doesn't) by Nandixon. One argument for folate cycling being involved in BH4 levels has to do with the idea that MTHFR can run "backwards" and recycle BH4, which it seems is not likely in vivo.

However, I found a second way 5MTHF might influence BH4 and NOS in this article, which is new to me. It would seem to indicate that 5MTHF interacts with NOS and BH4, probably to prevent BH4 from becoming BH2 (and thus preventing NOS from becoming uncoupled, where it produces more superoxide) But the article is from 2000, so perhaps the understanding is a bit old? What is your take @nandixon?

Also, DHFR, which converts both "folic acid" and dihydrofolate to tetrahydrofolate, also converts BH2 to BH4 using NADPH. So taking synthetic folic acid--which cycles through DHFR slowly--might slow this down and lower one's BH4/BH2 ratio.

@oh_noes: I realize I am coming to this discussion quite late, and you may have gotten your answers by now, but:

1. If the above paper is correct, BH4 does require methylfolate to work well
2. I have never heard that methylfolate was contraindicated for those with sulfur issues. There is the issue of methyl sensitivity, but for what it is worth, my experience with methyl donors (including methylfolate) is that it took a little while to get used to a higher dose, but I did get used to it. My understanding is that methyl sensitivity has to do with how quickly we can recycle catecholamines with COMT and how sensitive our bodies are to them. (I think through the vitamin d receptor, assuming heartfixer guy is right. Which it seems he is not always.) The theory as I understand it is that if one has mutations in the COMT or VDR genes, like I do, then taking more methyl groups will produce more catecholamines that we inactivate slowly (COMT mutations) and that our bodies will be more sensitive to (VDR mutations) which will end up causing insomnia, et. But my body, at least, was able to adapt over time, and I now do quite well with fairly high doses of methyl donors.

My understanding is that, since "methyl-sensitivity" is theorized to be related to genes having to do with neurotransmitters and not SAMe directly, and since our bodies seem to be able to adapt to these changes, we actually want to get our bodies used to taking higher amounts of methylfolate--although how high anyone should go is a matter of some discussion.
 
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nandixon

Senior Member
Messages
1,092
However, I found a second way 5MTHF might influence BH4 and NOS in this article, which is new to me. It would seem to indicate that 5MTHF interacts with NOS and BH4, probably to prevent BH4 from becoming BH2 (and thus preventing NOS from becoming uncoupled, where it produces more superoxide) But the article is from 2000, so perhaps the understanding is a bit old? What is your take @nandixon?
Yes, that work has been updated to show the involvement of peroxynitrite. Last that I was aware, the current understanding (and I haven't researched this in a while) is that methylfolate (MTHF) helps maintain BH4 levels (and NOS coupling) by preventing oxidation of BH4 by peroxynitrite, i.e., MTHF possibly acts as a unique antioxidant in this regard. This was reported in 2006. ("5-Methyltetrahydrofolate Rapidly Improves Endothelial Function and Decreases Superoxide Production in Human Vessels"; http://circ.ahajournals.org/content/114/11/1193.long)
 

nandixon

Senior Member
Messages
1,092
In terms of folates being involved in the recycling of BH2 to BH4, here is an excellent explanation of how that happens (or doesn't) by Nandixon. One argument for folate cycling being involved in BH4 levels has to do with the idea that MTHFR can run "backwards" and recycle BH4, which it seems is not likely in vivo.
Just to add something here as well, in the 2000 study ("Folic Acid Reverts Dysfunction of Endothelial Nitric Oxide Synthase") you gave the pdf link for, the authors noted that they had previously done an actual in vivo study to show that:

"With regard to the first option of improved redox state, it has been suggested that MTHF may increase regeneration of BH4 from qBH2.[37] However, we have previously found that biopterin levels in hypercholesterolemic patients are not significantly different from levels found in healthy controls.[25] Moreover, folate therapy did not show any effect on biopterin levels in vivo,[30] thus ruling out the first option."

This reinforces the analysis that Yasko's theory that the enzyme MTHFR runs in reverse to regenerate BH4 in vivo is not correct. (That's aside from her confusing q-BH2 with BH2.)

The key thing to understand, I think, with respect to the relationship between folate and BH4, is (in simple terms) that methylfolate helps maintain BH4 levels through its antioxidant action against peroxynitrite (and not by MTHFR running in reverse to recycle BH4 from q-BH2, which only appears to happen in vitro).
 

Critterina

Senior Member
Messages
1,238
Location
Arizona, USA
Just to add something here as well, in the 2000 study ("Folic Acid Reverts Dysfunction of Endothelial Nitric Oxide Synthase") you gave the pdf link for, the authors noted that they had previously done an actual in vivo study to show that:

"With regard to the first option of improved redox state, it has been suggested that MTHF may increase regeneration of BH4 from qBH2.[37] However, we have previously found that biopterin levels in hypercholesterolemic patients are not significantly different from levels found in healthy controls.[25] Moreover, folate therapy did not show any effect on biopterin levels in vivo,[30] thus ruling out the first option."

This reinforces the analysis that Yasko's theory that the enzyme MTHFR runs in reverse to regenerate BH4 in vivo is not correct. (That's aside from her confusing q-BH2 with BH2.)

The key thing to understand, I think, with respect to the relationship between folate and BH4, is (in simple terms) that methylfolate helps maintain BH4 levels through its antioxidant action against peroxynitrite (and not by MTHFR running in reverse to recycle BH4 from q-BH2, which only appears to happen in vitro).
This is really interesting because so many of us with the MTHFR A1298C are operating under the assumption that methylfolate is helping depression, anxiety, etc. because we are getting more neurotransmitters out of the biopterin cycle - which could still be true with your explanation, because there is more BH4. Some questions come to mind (editing starting here because something happened and it posted before I was through):

1. How would an enzyme have different in vitro and in vivo characteristics, such that the reaction is reversible in vitro but not in vivo?

2. How do hypercholesterolemic patients form a good model for folate therapy - what didn't the therapy do: lower cholesterol? raise biopterin? Why would they choose this population? Would it be the same for the rest of us with normal cholesterolemia?

3. Would something else be affecting the "improved redox state" they were looking for in this population?

4. What is that antioxidant action against peroxynitrite that you are referring to? I've never seen that equation.

Thanks for your patience with me. I am not a truster of Yasko's interpretations of biochemistry in general, despite the great work she does clinically. I'm just having a hard time getting my brain around this one.
 
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Gondwanaland

Senior Member
Messages
5,094
2. How do hypercholesterolemic patients form a good model for folate therapy - what didn't the therapy do: lower cholesterol? raise biopterin? Why would they choose this population? Would it be the same for the rest of us with normal cholesterolemia?
Because high cholesterol = high inflammation?
4. What is that antioxidant action against peroxynitrite
By raising uric acid?
 

picante

Senior Member
Messages
829
Location
Helena, MT USA
Last that I was aware, the current understanding (and I haven't researched this in a while) is that methylfolate (MTHF) helps maintain BH4 levels (and NOS coupling) by preventing oxidation of BH4 by peroxynitrite, i.e., MTHF possibly acts as a unique antioxidant in this regard. This was reported in 2006. ("5-Methyltetrahydrofolate Rapidly Improves Endothelial Function and Decreases Superoxide Production in Human Vessels"; http://circ.ahajournals.org/content/114/11/1193.long)
That study talks about eNOS. Would the same mechanism work for iNOS?

I'm asking because I've got three (3!) homozygous NOS2 mutations. This looks to me like the worst part of my methylation profile. What to do, what to do?

Thanks, I'm taking a crash course from all you fine people!
 

picante

Senior Member
Messages
829
Location
Helena, MT USA
By the way, how would you recommend lowering ammonia?
http://forums.phoenixrising.me/inde...reddds-protocol-ammonia-other-problems.34225/
I asked the same question on the above thread. @Gondwanaland had a whole list of suggestions, and @ahmo chimed in that adding malic acid to the sodium bicarbonate baths worked really well for her.
I'm still experimenting, but one thing I've found effective is to drink 1/8 tsp. malic acid powder (bulk) + a smidgeon of magnesium oxide, dissolved in water. (Note that MgO + H2O forms magnesium hydroxide, which is basically (pun intended) milk of magnesia.
Next I'll try the footbath ahmo suggested. Keep us posted if you find something really effective.
 

ahmo

Senior Member
Messages
4,805
Location
Northcoast NSW, Australia
I'm only on this page in the moment because of picante's tag above. So I'm taking this opportunity to note my current situation. I have no idea if it's covered here or elsewhere, because I'm just too much "in" it, that looking for understanding is beyond me just now. That is, it seems to me that having just spent 4 very intense weeks being far more active than I've been for years, by necessity, oxidative stress is pushing up my ammonia levels. A couple weeks ago I ran into trouble after taking high doses (for me) of B2, and there was a near-immediate high ammonia response. But this is not acute like that. Everything in me knows that the only place I belong right now is in bed. Or I will be in big trouble. AND, I'm also experiencing high ammonia, increased need for malic acid. Wondering if this rings true for anyone else, or fits into some pathway. o_O
 

Critterina

Senior Member
Messages
1,238
Location
Arizona, USA
Because high cholesterol = high inflammation?

By raising uric acid?
Thanks, Gondwanaland. I totally don't understand this yet. I would think CRP would be a better indication of inflammation. And that uric acid cycle is still beyond me. All the simplified diagrams I've seen are too simplified for me to learn anything from them. Have you posted a good one? You've been so good about posting other biochemical cycles, that I have appreciated...I might have missed that one.
 

ahmo

Senior Member
Messages
4,805
Location
Northcoast NSW, Australia
@Gondwanaland I don't think I'll be going anywhere with folate. I have no symptoms indicating going either up or down. I believe what I have is a whole body response to overdoing, red flags for an upcoming crash if I don't stop now.
stop-sign-smiley.gif
 

nandixon

Senior Member
Messages
1,092
That study talks about eNOS. Would the same mechanism work for iNOS?

I'm asking because I've got three (3!) homozygous NOS2 mutations. This looks to me like the worst part of my methylation profile. What to do, what to do?

Thanks, I'm taking a crash course from all you fine people!

I would think methylfolate could act as a peroxynitrite scavenger for iNOS (NOS2) in the same way it does for eNOS (NOS3) to help maintain BH4 levels and prevent decoupling.

I don't know offhand whether your homozygous NOS2 SNP results are up-regulations or down-regulations of nitric oxide (NO) production, or a combination, but my recollection is that iNOS tends to be up-regulated in ME/CFS (due to induction by cytokines, for example).
 

nandixon

Senior Member
Messages
1,092
This is really interesting because so many of us with the MTHFR A1298C are operating under the assumption that methylfolate is helping depression, anxiety, etc. because we are getting more neurotransmitters out of the biopterin cycle - which could still be true with your explanation, because there is more BH4. Some questions come to mind (editing starting here because something happened and it posted before I was through):

1. How would an enzyme have different in vitro and in vivo characteristics, such that the reaction is reversible in vitro but not in vivo?

2. How do hypercholesterolemic patients form a good model for folate therapy - what didn't the therapy do: lower cholesterol? raise biopterin? Why would they choose this population? Would it be the same for the rest of us with normal cholesterolemia?

3. Would something else be affecting the "improved redox state" they were looking for in this population?

4. What is that antioxidant action against peroxynitrite that you are referring to? I've never seen that equation.

Thanks for your patience with me. I am not a truster of Yasko's interpretations of biochemistry in general, despite the great work she does clinically. I'm just having a hard time getting my brain around this one.
I've talked about this before here (http://forums.phoenixrising.me/inde...sive-cbs-ammonia-fix.31835/page-2#post-500142), but you have to understand that this is all almost entirely a moot point.

The initial fundamental problem is that it seems clear that Yasko confused q-BH2 with BH2 when she found the research showing MTHFR can run in reverse - in vitro - to convert q-BH2 to BH4.

In the human body, that reaction is actually carried out by DHPR (aka QDPR).

So a person is likely not going to have a problem converting q-BH2 into BH4 unless there is a problem in QDPR. (And typically this will be congenital, if I remember correctly.)

And with respect to the recycling of BH2 (as opposed to q-BH2), that is handled by DHFR (not to be confused with DHPR).

And so a person is likely not going to have a problem converting BH2 into BH4 unless there is a problem in DHFR. (Note that both green tea and, presumably, folic acid will interfere with this enzyme.)

So in either case, whether we're talking about the conversion of q-BH2 into BH4, or BH2 into BH4, MTHFR is not likely to be directly involved.

If in fact Yasko is really seeing lower BH4 levels in her patients with MTHFR A1298C, it's not going to be because MTHFR is having problems recycling BH2, because it definitely doesn't perform that function, and it probably doesn't recycle q-BH2 in vivo.

Rather the problem, relative to MTHFR, will simply be whether a person is making enough methylfolate for it to scavenge peroxynitrite to prevent the oxidation of BH4 (i.e., BH4 -> BH2), at least according to the 2006 reference I cited in an earlier post.

And this is dependent on folate intake (either methylfolate or folinic acid) - regardless of whether a person has a C677T variation, an A1298C variation, or neither.

So there should be no need to treat A1298C as special with respect to BH4.
 

picante

Senior Member
Messages
829
Location
Helena, MT USA
I'm only on this page in the moment because of picante's tag above. So I'm taking this opportunity to note my current situation. I have no idea if it's covered here or elsewhere, because I'm just too much "in" it, that looking for understanding is beyond me just now. That is, it seems to me that having just spent 4 very intense weeks being far more active than I've been for years, by necessity, oxidative stress is pushing up my ammonia levels. A couple weeks ago I ran into trouble after taking high doses (for me) of B2, and there was a near-immediate high ammonia response. But this is not acute like that. Everything in me knows that the only place I belong right now is in bed. Or I will be in big trouble. AND, I'm also experiencing high ammonia, increased need for malic acid. Wondering if this rings true for anyone else, or fits into some pathway. o_O

I hope you're feeling better, dear ahmo. What you say here about B2 is a good clue for me. I tried taking some sublingual FMN recently and in a few days had major inflammation in my lower back. Plus a steady descent into depression.

I've been struggling with ammonia for a while, but it did get worse while I was taking the FMN. And yes, the malic acid helps me with that. I seem to need 4 X 1mg methylfolate every day, pretty consistently.

I wonder if this happens because of problems converting it to FAD. T4 is needed for conversion apparently, and I don't have much T4 in my system.
 

picante

Senior Member
Messages
829
Location
Helena, MT USA
Yes, that work has been updated to show the involvement of peroxynitrite. Last that I was aware, the current understanding (and I haven't researched this in a while) is that methylfolate (MTHF) helps maintain BH4 levels (and NOS coupling) by preventing oxidation of BH4 by peroxynitrite, i.e., MTHF possibly acts as a unique antioxidant in this regard. This was reported in 2006. ("5-Methyltetrahydrofolate Rapidly Improves Endothelial Function and Decreases Superoxide Production in Human Vessels"; http://circ.ahajournals.org/content/114/11/1193.long)
This was very helpful.

If in fact Yasko is really seeing lower BH4 levels in her patients with MTHFR A1298C, it's not going to be because MTHFR is having problems recycling BH2, because it definitely doesn't perform that function, and it probably doesn't recycle q-BH2 in vivo.

Rather the problem, relative to MTHFR, will simply be whether a person is making enough methylfolate for it to scavenge peroxynitrite to prevent the oxidation of BH4 (i.e., BH4 -> BH2), at least according to the 2006 reference I cited in an earlier post.

And this is dependent on folate intake (either methylfolate or folinic acid) - regardless of whether a person has a C677T variation, an A1298C variation, or neither.

This really sorted out some confusion for me. I'm compound heterozygous for MTHFR, but I'm thinking the 3 homozygous NOS2 snps are having a bigger impact. Thanks, Nan!