Ask A Scientist Molecular Biology Archive

Name         abigail
status       student
age          17

Question -   -what are the histamines resposible for? is it
depresssion, alergies or blindnesss?
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Histamine "no suffix -s" refers to a specific compound that is a potent
inflammatory vasodilator naturally found in the body. Its function is to
increase the supply of blood to an injury or foreign substance that enters
the body. It can have a wide variety of physiological responses. For example
it stimulates the secretion of pepsin and acid by the stomach. Histamines
refer to related chemical compounds that stimulate similar responses.
Because vasodilation can produce a spectrum of physiological consequences,
it is difficult to say that histamines don't affect a particular response in
an individual. Itching, swelling, redness are all effects of histamines. Of
the symptoms you list -- depression, allergies, and blindness -- certainly
histamines are directly responsible for allergies. But one cannot rule out
whether histamines play (or don't play) a role in those, and other
conditions.
    You can find some additional info on the Newton Websites below.

 www.newton.dep.anl.gov/askasci/bio99/bio99385.htm
www.newton.dep.anl.gov/askasci/mole00/mole00321.htm

Vince Calder
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I have answered questions regarding histamine and antihistamines and hives,
which are all related so allow me to give a somewhat general answer to what
histamine is or does. 

Histamine is a chemical that is found pretty much throughout the human body
and in highest concentrations in lung, skin and upper gastrointestinal
tract.  Basophiles, or mast cells contain large basic staining granules that
store considerable amounts of histamine and these are the typical culprits
of histamine release.  Histamine can be released from these cells following
various physical disruption including contact (e.g., a scratch on the
skin...contact urticaria), contact with cold (e.g., ice on the skin) or
chemical initiation such as in "allergic responses" where contact with an
allergin like pollen causes the body to release IgE antibodies which in turn
bind to mast cells which then cause the mast cells to release their
histamine.  In the skin, if contact or chemical initiation of histamine
release occurs, the classic response follows: vasodilation (blood vessel
expand), increased capillary permeability (capillaries leak fluid and some
cells into the spaces between cells), and erythema (the area becomes
red)...A HIVE!    Glandular hypersecretion (nose and brochioles release
mucous), smooth muscle spasm, and tissue infiltration with eosinophils and
other inflammatory cells are also responses of respiratory system tissues. 

The most common causes of hives is allergies to foods but drugs and viral
infections can trigger hives for weeks to months. As I wrote above, hives
can also be caused by contact with something hard ( a scratch), cold, or
even sunlight.  Foods that are common culprits in causing hives are, fresh
berries, chocolate, nuts, certain fish, tomatoes, eggs, and dairy products.
Too bas spinach and kale and a all those other things we don't find enticing
are not common causes and easier to give up. Food additives and
preservatives also are reasonably common causes of hives. 

Hives can appear within minutes to hours and last for minutes to
hours...even days in some cases.  

I have my theories on what the "normal function of histamine is but suffice
to say that scientists are still arguing why our bodies have histamine other
than to aggravate us.

pf 
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