ú    Subject: NEWSWIRE immune.endrocrine review

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INTERACTION OF IMMUNE AND ENDOCRINE SYSTEMS
DURING ACUTE AND CHRONIC STRESS (c)

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        In the words of Dr. Selye, stress is "the non-specific" response
of the body to any demand made upon it.  Specific responses are the ones
you can see such as crying, shivering, sweating, fainting, vomiting,
etc.  The non-specific responses are the unseen factors that incite
these specific responses.  For example, an important deadline is missed.
The boss gets angry and vents his/her feelings loudly.  This is a
specific response to the stressful situation.  The non-specific response
is the tensing of muscles, and the increased heart beat and blood
pressure.   To understand how these non-specific responses occur, it
helps to know something about the endocrine system.  The endocrine
glands that get the most attention are the pair of adrenals, which sit
on top of each kidney.  Each consists of two parts - an outer layer
called the cortex and an inner portion called the medulla.  These two
glands are under the control of the pituitary gland, which is located
at the base of the brain.  This gland is under the control of the
hypothalamus, the real conductor of the whole system.  It acts as a
bugging device on all incoming messages to the brain about sight, sound,
taste, and smell.  The hypothalamus not only has the  nerves coming in
with messages, but it is also in contact with the blood of the
circulatory system.  It directs responses by sending nerve signals
through the Autonomic Nervous System (ANS), and also by secreting
hormones that travel down to the pituitary gland.  The pituitary sets
its hormones off to the other target organs in the body, e.g. thyroid,
pancreas, adrenals, etc.



   Diagram


        When the hypothalamus receives a message to react to a crisis, it
sends a message via the ANS to the adrenal medulla and also releases
corticotropin releasing hormone (CRH) to the pituitary.  The pituitary,
in turn, releases adrenocorticotropic hormone (ACTH) which effects the
adrenal cortex.  The adrenal medulla, having received the nerve signal
from the hypothalamus, secretes adrenalin (epinephrine and nor-
epinephrine) into the blood stream to make the pituitary to secrete
more ACTH, the heart pump faster, the blood vessels narrow so that
pressure will rise and send oxygen to where it's needed, and the fat in
the adipose tissue to be mobilized, therefore, raising the blood lipid
level.  The lungs and air passages relax, too, to help the oxygen supply
still further.  Blood tends to be drawn toward the muscles, in readiness
for action, leaving the face white and the digestion interrupted.  In
the other part of the adrenals, the cortex the ACTH causes cortisol and
cortisone to be secreted.  Cortisol (a corticoid)  a critical feature
of the physiologic response to stress and illness.  It mobilizes the fat
(triglicerides) in the adipose tissue to increase blood lipid levels,
and it also induces the liver to breakdown protein and fat to glucose.
Meanwhile, the thyroid, parathyroid, sex organs, and a portion of the
pancreas get the green light, from other releasing hormones origination
from the pituitary, to secrete their particular hormones.  All of these
events, go on inside to prepare the individual for the "fight or
flight" response.  The sequence of events is the same whether there is
an actual crisis or a perceived crisis taking place, i.e., you are
about to be hit by a car or your boss drops unexpected work on your desk
to be completed within an unreasonable short-time deadline.  Either way,
your are ready to spring into action; people are able to perform
superhuman feats of strength, speed, and quick-wittedness in emergency
situations.  But, when the adrenal alarm goes off and there is no
superhuman physical feat to be accomplished, you have all these hormones
circulating in your blood with nothing too do; the result of their
actions within your body is then deleterious to both your body and your
health.  Dr. Selye put these malfunctions together into a neat"stress
concept of disease".  Here is a summary of his conclusions.  In the
face of continuing (chronic) stress, the body goes through three
phases.  One - alarm bells ring and the body reacts directly to the
stress.  Two - comes adaptation to the situation and increased
resistance.  Three - the final phase is exhaustion and collapse.  Dr.
Selye had seen the signs of stage two - shrunken thymus glands (an
important part of the immune system), and enlarged adrenal cortexes,
in both humans and rats.  These "non-specific"signs are what he referred
to as "the syndrome of just being sick".  Over the years, other doctors
as well as he noticed the same things, yet, these doctors never followed
through to nail stress as the culprit.  Dr. Selye even found out that
different people respond to stress in very individualistic ways.

        Let's get back to a description of the"fight or flight" response.
The epinephrine, nor-epinephrine, cortisol and cortisone deliver an
alarm throughout the body.  We will only look at a select number of this
total.  First, let's look at epinephrine and nor-epinephrine.  These are
responsible for the most visible responses of the body.  The increase in
blood pressure and heart rate, the increase in the rate of breathing,
and the tensing of muscles.  All these measures increases the work of
the heart to pump blood.  Now, let's look at cortisol, which directs the
body to release fats form storage in the  adipose tissue into the blood.
The serum lipid rises and when it is not used as a source of fuel by
cells it is deposited in the blood vessels.  This is not so good as it
leads to artherosclerosis.  Another one is cortisone,  which damps down
the body's immune responses through the lymph nodes particularly the
thymus gland, as one does not need to be worried about a scratch when
there are more serious things to be concerned with during a crisis (even
when they don't exist).  Other immune responses to chronic stress are:
an individual's immune system shows sustained depression of Natural
Killer (NK) cells, there are changes in the number and competence of
lymphocytes released into the blood, and the function of macrophages and
lymphocytes are inhibited, and the ability of lymphocytes to divide is
affected.  These responses are referred as immuno-suppression.

        These are all okay, if the stress is acute (occurring once and
then over), however, if stress is chronic (the person is still huffing
and puffing in anger, or still fretting with worry 6 hours later) the
effects of the adrenal hormones are detrimental.  Chronic stress is a
result of the pace of life today - hectic, deadlines, quotas, global
economics with 24-hour business, constant communication with cellular
phones and fax machines, modems attached to computers, proliferation of
information (computerized), down-sizing of companies/institutions to
stay completive, and pagers!!  One can scarcely find time to slow down
to sleep, let alone, to relax and rest.  The are constantly faced with
the pressure of never-ending-work, the noise of the open office and
traffic,  and the demands of family; it all looks and feel like a
vicious circle.  There is never any time leftover.

        The trick is to break the stress cycle by paying yourself first,
i.e., make time for yourself and set it aside to let BOTH your BODY and
your MIND slow down on a daily basis.  How you do it is up to you, and
YOU ARE WORTH IT!!!!!  Try to establish what it is that you really want
form life and, if you're not happy, stop doing what other people think
you ought/should  be doing.  Try to be a graceful loser, and to develop
the knack of knowing when something is worth getting steamed up about
and when it isn't.  The AA serenity prayer comes in handy; "God grant
me the serenity to accept the things I cannot change, the courage to
change the things I can, and the wisdom to know the difference".  Nobody
knows your stress thresholds better than you do.  You should be able to
know instinctively when you've had enough, when it's time to switch off,
to quit.  Each individual must find his/her own tolerance level of
stress (comfort zone), because below that you'll feel bored and
frustrated, and above that you'll suffer exhaustion.  Reactions to
stress may vary, but research shows that a tremendous number of
unexplainable illnesses occur within a short time after an individual
has been exposed to a particular major stressor.

        Genetically every one is different, including their  personalities.
Some personality types are more prone to illness than others.  There
is a growing body of opinion that this is because it is how the
different personality types handle stress that is the key to their
illnesses.  If one is typically "type A" most or all of the time, that
person is very tense physically and intense psychologically.  This means
that there is a "fight or flight" response is going on in their bodies
continuously, and their bodies hardly have a break in the stress cycle
for the hormones to subside, and the body tissues and organs are
constantly being assaulted with the stress hormones.  As a result, the
thymus shrinks, the rest of the immune system becomes weakened, the
adrenal cortexes increase in size, and the person becomes more
susceptible to disease.  Health is about balance, i.e., everything in
moderation - work, sleep, play, nutrition, exercise.  Or, stop to
really take time to smell the roses along the way!

Bibliography


1.      The Adrenal.  Scientific American Medical. Scientific American, Inc.
        New York, U.S.A.  1990.

2.      Immunology.  Scientific American Medical.  Scientific American, Inc.
        New York, U.S.A.  1990.

3.      Chronic Fatigue, The Silent Epidemic by William Vayda.  Simon and
        Schuster, Australia. 1992.

4.      Function of the Human Body by A.C. Guyton, M.D.  W.B. Saunders
        Company.  Toronto. 1974.

Biography:   Dr. Philipa Corning has a Doctorate in Microbiology;
additional education and is continuing studies in "The Physiology of
Exercise", "Nutrition and Exercise"; is a trained Aerobic Fitness
instructor; and current president of the Ottawa MESH chapter (M.E.
Self Help).

Copyrighted Dr. Philipa Corning 1993
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