[CH] Re: Heat Tolerance

George Nelson (70431.3065@compuserve.com)
Sun, 27 Feb 2000 10:58:22 -0500

There is a general observation that pepper heat tolerance varies from day
to day.  Calvin (of powder fame) observed that his experience was similar
to athletic conditioning.   The more he ate and the hotter he ate, the more
he could handle.

Sometime last summer, I read the article about the action of capsaicin at
the cellular level in Nature (rather, tried to cope with the huge words and
scientific style!).  One phrase they used struck me.  It was "...kill the
cells..." or something like that.  This has some long-term implications if
"killing" is what really occurs.  It is hard to believe this happens,
because List experience shows a return in sensitivity, and also those who
use capsaicin creams for pain relief have to keep applying them.  In
addition, I believe I have heard that nerve cells, when killed, are not
regenerated.  However, experience would indicate they keep on living or
else new ones do indeed grow.

It is well-known that capsaicin causes the depletion of P factor which is a
hormone required to transmit pain signals.  The Nature article indicated
this was done because capsaicin acted on the calcium channels in the
membranes of very specific nerve cells.  An inordinately small dose of
capsaicin has the effect of turning them on to their full response level. 
This exhausts the transmitter and takes it out of service for some time
until the transmitter can be re-synthesized in the cells.  If this is the
case, Calvin's athletic conditioning analogy is a good one (stress the
system and it adapts at the cellular level to accomodate the stress!).  Lay
off peppers for awhile, and the nerves are able to replenish the ability to
transmit the pain.

It has been awhile since I read it, so at this time, I do not recall the
issue of Nature, nor do I recall the title of the article.  It was
well-covered in the media, however, when published.

George