Eosinophil Question...

Hey MLTs and Juelle,

Vanessa and I I were reading the Hematology text book today, and noticed its mention of eosinophils having antihistamine in their pink granules. My understanding was always that it is histamine in the granules. Have I been wrong all these years. When I looked in about 3 other textbooks, it mentions only that they release cytotoxic proteins/enzymes.
In looking them up on Wikipedia it says that they release histamine, but are also modulators... does that mean they release both? Pubmed has no answers either, just found stuff on horse eosinophils.

---Does anybody know what is released from pink/red granules in eosinophils????

Thanks in advance,
Dan and vanessa.

Just wondering, where exactly in the text did you read this? I'm having trouble finding the specific statement. I know for sure that it's histamine, not antihistamine. I have nowhere in a book that I can point this out, but this is something that has been hammered into my head somewhere along the line. You're definitely not crazy!

I know that eosinophils have a little histamine, but the WBC that is really 'famous' for it is the basophil. Baso's also have the substance that triggers anaphylactic shock. It seems counter-intuitive that eosinophils are the ones associated with allergies when baso's have the lion's share of histamine, but from the sounds of the site below, they are what stimulate basophils to release their histamine.

There seem to be four different things in the pink granules that help with various functions, the most important appears to be Major basic protein(MBP). I have no other sites to correlate this site with, but it does give a good explanation and seems to be in line with the bits and pieces of other sites and sources as well as our text. It also sounds like there is much more to learn about them in terms of their specific function.

http://nic.sav.sk/logos/books/scientific/node14.html

I hope the link works(I've never made one before), if not let me know and I can email it to you. Hopefully this is helpful. If not, at least you've got me thinking about it!

Regards,

Lindsay

Please see pg 130 of your text for granule contents. Notice that histamine/antihistamine is not listed.

The eosinophil is considered to be a homeostatic regulator of inflammation that leaves the circulating blood when adrenal cortical hormone increases. It attempts to suppress inflammatory tissue reactions to prevent the excessive spread of inflammation. Eosinophils proliferate in response to antigenetic stimulation and contain substances that inactivate factors released by mast cells and basophils (histamine/heparin) and other soluble substances in the blood such as the coagulation factors, complement, and hormones.

antihistamine properties perhaps??
I'll look into it more and let you know.
Juelle

Hi all,

So, page 3 of the textbook a typo, in the little bullet on EOs, or is it right, but not one of the important tidbits, about EOs?

Vanessa

For the sake of simplicity...lets say that eosinophils are filled with granules that are histamine antagonists (antihistamines a broad general term)

For our purposes now...if you know that eosinophils are leukocytes...I am happy.

We will do more on eosoinophils in Leukopoiesis.

Juelle

Thanks!