On the role of carnosinase.

Olafur Pall Olafsson

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May 11, 2008, 4:41:13 AM5/11/08

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A few months ago I upped my dose of carnosine to 500mg twice daily
from 500mg once daily. One of the reasons I did not take more in the
past is that I did not want to take the risk of overriding the
carnosinase enzyme. I had asked myself the following question:

Why does the human body contain carnosinase, an enzyme that rapidly
hydrolyzes ingested carnosine to it's corresponding amino acids beta-
alanine and histidine?

One possible answer to that question is that perhaps having higher
amounts of carnosine in the body is harmful and the enzyme carnosinase
exists in humans to protect them from having too high levels of
carnosine in the body. Because of this possibility and my young age I
decided that the potential added benefits of taking higher doses of
carnosine were not worth the risk for me. Doing more research and
thinking I have since then become increasingly convinced that
carnosinase exists not to control carnosine levels but to provide a
source of histidine and beta-alanine. Based on that I decided to
increase my dose. Thomas Carter actually mentioned this possibility on
this group several years ago, citing some references (thanks Thomas).
Here is a link to that discussion: http://tinyurl.com/46ajan

In addition here is another abstract I came across that lends further
support to this:

Agents Actions. 1990 Nov;31(3-4):190-6.
Related Articles, Links

The presence and significance of carnosine in histamine-containing
tissues of several mammalian species.

Flancbaum L, Fitzpatrick JC, Brotman DN, Marcoux AM, Kasziba E,
Fisher H.

Department of Surgery, UMDNJ-Robert Wood Johnson Medical School,
New Brunswick.

Histamine is known to exert profound effects on the cardiovascular
system in many mammals. Carnosine (beta-alanyl-L-histidine) is a
dipeptide previously known to be present only in a few tissues. It is
our hypothesis that carnosine serves as a non-mast cell reservoir for
histidine, available for histamine synthesis during periods of
physiologic stress. To validate this hypothesis, we demonstrated the
existence of carnosine in multiple histamine-rich tissues in several
mammalian species; documented a metabolic link between carnosine and
histidine, histamine and 3-methylhistamine (a degradation product of
histamine) in unstressed animals, and showed that tissue carnosine is
decreased simultaneously with an increase in tissue histamine during
stress.

Publication Types:

* Research Support, Non-U.S. Gov't

PMID: 2085137 [PubMed - indexed for MEDLINE]

trigonometry1972@gmail.com |

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May 11, 2008, 6:50:48 AM5/11/08

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Might it be possible for supplemental beta-alanine and histidine
to downregulated the production of carnosinase?

I dimly recall considering histidine as a possible lower cost
alternative to carnosine. It seems I lost focus
and didn't put into practice.

You deserve a better response so I'll poke around
and see if I can provide any other comments.

trigonometry1972@gmail.com |

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May 11, 2008, 7:58:12 AM5/11/08

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On May 11, 3:50 am, "trigonometry1...@gmail.com |"

This piece may have been what suggested
the idea to Thomas Carter. I didn't go
back and look at the thread. There is
newer research since I looked last.

J Nutr. 1985 Jun;115(6):824-6.

Essentiality of histidine in adult mice.

Parker CJ Jr, Riess GT, Sardesai VM.

The difficulty in demonstrating a histidine deficiency in adult
animals may be due in part to the histidine reserve in
skeletal muscle in the form of carnosine.
Mice are unusual among vertebrates in that their
muscle is free of carnosine and its methylated analogue,
anserine. When mice were fed a histidine-free diet,
weight loss was noticeable within 3 d and continued
over a period of 18 d. At this point the animals had
lost 25-30% of their original weight. These results
are compatible with the view that a dietary histidine
deficiency can be offset by carnosine. Mice, whose
muscle contains no carnosine, show early signs of a
deficiency when deprived of histidine.

PMID: 3998873

Olafur Pall Olafsson

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May 11, 2008, 11:27:37 PM5/11/08

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On May 11, 11:58 am, "trigonometry1...@gmail.com |"

It's a possibility but I have not seen any study on the effects on
beta-alanine and histidine supplementation on the concentration of
carnosinase. On the other hand the activity of carnosinase would
likely be enhanced when taking beta-alanine and histidine because of
the resultant increase in it's substrate carnosine. In rats f.ex.
exercise has been shown to increase carnosine synthesis resulting in
elevated plasma carnosine concentration and an increase in the
activity of carnosinase http://pmid.us/14610252 .

> > I dimly recall considering histidine as a possible lower cost
> > alternative to carnosine. It seems I lost focus
> > and didn't put into practice.

Some of the benefits of carnosine are derived from it's breakdown to
histidine. And yes, for those specific benefits supplementing with
histidine directly would be a lower cost alternative. But not all of
the benefits of carnosine are derived from it's breakdown to histidine
so my recommendation is to take both carnosine and histidine.

> > You deserve a better response so I'll poke around
> > and see if I can provide any other comments.
>
> This piece may have been what suggested
> the idea to Thomas Carter. I didn't go
> back and look at the thread. There is
> newer research since I looked last.

I had not seen this one before, thanks. But I think this abstract is
more likely be the one that suggested the idea to him: http://pmid.us/16112643
It specifically talks about the benefits of carnosine being derived in
part from it's breakdown product histidine. I discussed this abstract
a while ago on this group. Here is a link to the thread: http://tinyurl.com/3w2muf

Olafur

Olafur Pall Olafsson

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May 11, 2008, 11:30:49 PM5/11/08

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Oops, that's the wrong url. Sorry here is the correct one: http://pmid.us/15234195