Fwd: diamine oxidase information

[Guest guest]

Hello,

I asked if I could share this info with our group, and she kindly gave

me the go-ahead. Now you can see why we are both so intrigued with diamine

oxidase...

Air hugs,

Jackie

Life is tough, but I'm tougher.

Diamine oxidase

Someone made a suggestion to me that spurred a bit of research, and I

believe you would be interested in what we have found. As usual, I'll start

with some background. All statements refer to human findings unless

specified otherwise.

After histamine has been released by mast cells and/or basophils, or after

it has been eaten in food, it is changed by an enzyme named diamine oxidase.

This change causes histamine to lose its ability to " turn on " histamine

receptors, so is important in clearing active histamine out of our system

quickly. The question was this: If a person is deficient in diamine

oxidase, will they have symptoms resulting from increased histamine levels

in their system?

Diamine oxidase is continuously released by the intestinal mucous membrane

and is found inside the intestine as well as being carried by the lymphatic

vessels into the circulating blood. One abstract we found mentioned diamine

oxidase in placental tissue, so there may be several tissues that produce

it, but small intestinal mucosa seems to be the most important. The serum

level of diamine oxidase is considered to indicate the amount of functioning

small intestine mucous membrane tissue a person has.

Histamine in food has been shown to cause reactions that look like food

allergy; these reactions may be due to reduced diamine oxidase activity.

One group worked with patients who had chronic idiopathic urticaria. They

measured serum levels of histamine and of diamine oxidase while the patients

were eating a normal diet, then had them change to a diet including only

foods containing no histamine. Other foods that are frequently found to

cause allergic reactions were eliminated also. They did the same

measurements on people without urticaria as well. They found that people

with chronic idiopathic urticaria, eating their normal diet, had a higher

serum level of histamine than the well people did. When the diet was

changed, though, the people with urticaria had the same serum level of

histamine as the well people. They also had a significant reduction in

symptoms. What caught my eye (and mind) was the finding that people with

urticaria had a lower serum level of diamine oxidase than the well people,

and this was true both on and off the diet.

So it would appear that, at least for some people with chronic idiopathic

urticaria (and possibly with other types of histamine-related symptoms), the

problem lies in an inability to process histamine and inactivate it rapidly,

rather than from an increased secretion of histamine by mast cells or

basophils. These people would have a normal level of urinary histamine

metabolites and would have at least some relief from antihistamines.

OK, that is all very interesting, but how practical is it?

In order to be functional, diamine oxidase needs to have a copper atom as

part of its structure, so presumably having an adequate copper intake is

important in keeping our diamine oxidase working.

In rats, one group showed that a high content of protein in the small

intestine reduced the amount of diamine oxidase found in part of the small

intestine. Triglycerides and fatty acids increased the amount of diamine

oxidase being carried by the lymph system into the blood circulation. I

wouldn't really recommend increasing your intake of triglycerides, but it is

possible that increasing fatty acids, such as in oily fish, nuts, and

whatever else we can get M. (a member of the masto group) to tell us

about, may increase the ability of your body to deal with histamine rapidly.

Non-fat foods appear to increase diamine oxidase inside the intestine,

where it can deal with histamine in ingested food.

Another group of researchers added one of several antihistamines to diamine

oxidase in the test tube, then tested its ability to change histamine. Their

results showed that Benadryl caused an increase in enzyme activity (thus,

allowed increased metabolism of histamine), cimetidine (Tagamet) inhibited

diamine oxidase activity by 25% (thus, caused decreased metabolism of

histamine), and ranitidine (Zantac) and ketotifen had no effect on the

ability of diamine oxidase to change histamine. So, anyone still having

symptoms who is also

taking Tagamet might discuss with their doctor the possibility of changing

to Zantac or one of the other H2 antihistamines to see if their symptoms

decrease.

There are some drugs that are " commonly used in intensive care units " that

inhibit the action of diamine oxidase when tested in the lab. These drugs

may allow an increased level of histamine to accumulate in the body, causing

symptoms. These drugs may also cause symptoms to occur in people whose mast

cells are releasing excessive amounts of histamine but who are usually

adequately controlled by antihistamine. Strong inhibitors of diamine

oxidase included some of the drugs that are used as muscle relaxants in

surgery, such as d-tubocurarine, pancuronium and alcuronium; however

suxamethonium did not have that effect. Several of the cephalosporine

antibiotics inhibit diamine oxidase, such as cefotiame and cefuroxime

(Ceftin, Zinacef); however, cefotaxime (Claforin) had no effect on diamine

oxidase.

This may explain why some of us have increased symptoms when we take some

drugs.

And, finally, another group looked at the danger of a large amount of

dietary histamine. These researchers gave to pigs a drug that inhibits the

activity of diamine oxidase and then fed them a normal serving of food that

contains a large amount of histamine; symptoms occurred that in some cases

were severe enough to be life-threatening. Some of the drugs that strongly

inhibited diamine oxidase (and allowed an increased serum level of

histamine) were dihydralazine, chloroquine (used for malaria treatment),

pentamidine, cycloserine, clavulanic acid (Augmentin), dobutamine and

pancuronium (muscle relaxant).

I'm interested in knowing whether anyone feels that this information may

help explain some of your symptoms, and in discussing it with you.

References for this information are:

" Daily variations of serum diamine oxidase and the influence of H1 and H2

blockers: a critical approach to routine diamine oxidase assessment. By F

Wantke et al; from Inflamm Res 1998 Oct 47:396-400:

" Histamine plasma levels and elimination diet in chronic idiopathic

urticaria " by B. Guida et al; in Eur J Clin Nutr 2000 Feb 54:155-8

" Nutrients regulate diamine oxidase release from intestinal mucosa " by A

Wollin; in the Am J Physiol 1998 Oct 275:R969-75

" Changes in serum diamine oxidase activity during chemotherapy in patients

with hematological malignancies " by T Tsujikawa; in Cancer Lett 1999 Dec

147:195-8:

" Intestinal diamine oxidases and enteral-induced histaminosis: studies on

three prognostic variables in an epidemiological model " J Sattler and W

Lorenz; J Neural Transm Suppl 1990;32:291

" Inhibition of human and canine diamine oxidase by drugs used in an

intensive care unit: relevance for clinical side effects? " J Sattler et al,

Agents Actions 1985 Apr; 16(3-4):91-94

Cheers, NZ 61 SM & UP

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