# Serotonin and IBS from the Winter 2000 issues of IFFGD's Participate Newsletter



## eric (Jul 8, 1999)

Serotonin and IBSFrom the Winter 2000 issue of Participate:iffgd ï¿½ 1999-2001 IFFGD http://www.aboutibs.org/IFFGD_Serotonin.html ------------------ http://www.ibshealth.com/ www.ibsaudioprogram.com[This message has been edited by Jeffrey Roberts (edited 01-23-2001).]


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## JeanG (Oct 20, 1999)

Thanks for posting this, Eric. I hadn't realized that the brain had the 5HT1 and 2, and the gut different ones. This is one I'm going to print out and keep for reference.







JeanG


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## BQ (May 22, 2000)

Eric, I'm trying to get it, I really am. Is the Seratonin the chemical that makes the contractions occur? "Dave, Dave's not here" HELP! BQ


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## Kathleen M. (Nov 16, 1999)

Serotonin is a neurotransmitter. What serotonin causes depends on what receptors the cell receiving it have. How nerves transmit information is by chemical. The electrical impulse goes down the nerve cell and if the conditions are met neurotransmitters are released. Neurotransmitters cross the space between the nerves (the synapse) and if the conditions are met, that nerve transmits an electrical impulse along it's length to release neurotransmitters at the end.When a nerve cell ends in the muscle, it tells the muscle to contract by releasing chemicals into the space between the nerve cell and the muscle cell. When serotonin binds to the 5HT-3 receptor this is the speed up signal. When 5HT-4 is bound by serotonin this is the slow things down signal. I'm not sure if the receptors are on the muscles or on the nerves, but I think it is the nerves. Drugs that block 5HT-3 help with diarrhea, and drugs that block 5HT-4 help with constipation.KK.


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## BQ (May 22, 2000)

K, I'm embarrassed yet again. Note the time of this post. I just found this; quite by accident actually. I was beginning to think the Levsin was making me more loopy than I thought. I knew Eric had posted something again, but couldn't find it. Copywrite thing...Jeff... moved post to here. Got it. I'm right on top of things as usual!







I actually wrote your above post on a piece of paper because at the moment it escapes me how to print this out. I'll remember though, eventually.... I'm beginning to think I gaining on this understanding. Thanks so much. BQ


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## Mike NoLomotil (Jun 6, 2000)

Another intersting aspect of what all that serotonins stored in the gut is for and does, is that serotonin is one of the main mediators of immune response of the gut. In the immediate-phase of an immune response mast cells release many mediators but the primary ones are histamine and serotonin, as they are powerfully "vasoactive", and essential element in marshalling the bodies circulating immune defense cells to the site of any insult or danger (cause the blood vessels to dilate and allow fluid and cells out). As has also been pointed out in studies related to investigating 5HT receptors in and of themselves, serotonin acts to increase smooth muscle contraction. Serotonin will also be released by platelets as they become activated in an immune response. Some investigators using techniques of jejunal isolation in patients with non-atopic food sensitivities manifesting as bowel dysfunction symptoms (commonly associated with so called "d-predominant IBS") have found surprising but consistent mast cell degranulation of small bowel mucosal mast cells in response to provocation by foods to which the patient was confirmed reactive by double blind placebo controlled oral challenge, and to which they were NOT allergic (IgE negative). Another apparently "local" mechanism heretofore unseen elicits mast cell response along with basophils as well as eosinophils (suggesting on-going not acute insult)!As most of the serotonin in the body is stored in these compartments of the gut, it is suggestive of where the serotonin is "coming from" as well as the whole upregulation of neural and smooth muscle response (immune mediators alter the depolarization threshold of the gut wall smooth muscle as well, reducing the stimulus that must be applied to result in depolarization and contraction: twitchy muscles). This is very intriguing work has been going on in Sweden primarily, and the same group has recently been "diggin deeper" into the food intolerance phenomena immunologically, found large numbers of CD1d positive cells in the lamina propria of food-sensitive patients NOT present in confirmed Non-reactive patients. Hmmm...complement receptors. The small bowel plot thickens.MNL_______________ www.leapallergy.com


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## Guest (Jan 25, 2001)

Lotronex was alosterone a 5ht3 receptor antagonist. I have done some research and for that ondesterone and grandisterone are also 5ht3 receptor antagonists marketed under the names of Kytil and Zofran respectively. Are there any compatibilities? They are prescribed for post-op vomiting I believe but are there compatibilities with alosterone that would give relief to an IBS-D female that was truly helped by Lotronex?


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## badfoot (Oct 5, 1999)

Gracias, again. It is great to understand some of these basic issues about serotonin.


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## eric (Jul 8, 1999)

David N, there are similarities with those drugs. There is also remeron.------------------I work with Mike and the audio 100 program. www.ibshealth.com www.ibsaudioprogram.com


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## Guest (Feb 22, 2001)

Eric, my question would be this. If Kytril and Zofran are 5ht3 receptor antagonists, and if they act on seratonin in the gut to relieve post op vomiting, and if they have been judged to be safe, is there any likelihood that either of these drugs would act the same way as Lotronex a 5ht3 receptor antagonist. If my wifes doctor is able to prescribe either of these two drugs is it worth a try. They are not experimental, they are on the market, they are safe, and they may help. Am I missing something in the science here?


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## Kathleen M. (Nov 16, 1999)

It makes some logical sense that they could be tried. Whether the doc is willing or not is another matter, but it maynot hurt to ask or try (check the potential side effects on something like www.drugchecker.com to help with that decision). Also you may have to pay out of pocket or have some negotiations with insurance for off-label use.K.------------------I have no financial, academic, or any other stake in any commercial product mentioned by me.And from the as if IBS isn't enough of a worry file...from New Scientist's Feedback column: photographed on the door of a ladies' loo in the Sequoia National Park in California by reader Liz Masterman: "Please keep door closed to discourage bears from entering."


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## Mike NoLomotil (Jun 6, 2000)

DAVE:I am sure I have read a paper that will answer that questions and it is in this mountain here in my office...it reelated to that "off-label use" so to speak. While the results where not astounding I beleive I remember there appearing to be some level of efficacy....just cannot memorize them all anymore. Feel like an old man who cannot remember anything except how to order the Ceasar Salad....If nobody else "pops up" with it/the, all of a sudden I will look around over the weekend to see what I have to help answer your questionMNL___________ www.leapallergy.com


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