Richard E. Clopton
septate at tamsun.tamu.edu
Sun Mar 20 13:54:46 EST 1994
Niccy Scholfield (Scholfield at bchm.unp.ac.za) wrote:
: We were wondering just exactly how tattoos work. Unlike a protein dye that
: comes off when the skin sloughs off, a tattoo is guaranteed for 99 years!
: Niccy and Linda.
I don't profess to know all the answers, but I might be able to help you along
your way. If any netter finds a glaring error--feel free to correct. I'm
just an "old classical zoologist".
Tattoos: This is my understanding of how tattoos work-->
The dyes/pigments are engulfed by macrophages. Normally (or so I
understand) macrophages are wandering bodies; however, when they
engulf enough material, they remain static until the material is
digested or broken down. The trick seems to be that they can't break
down the pigments/dyes used in the tattoo process--thus they hang
around in the same place indefinitely. Of course macrophages seem
to be VERY long-lived cells--so they tend to remain "painted in
place" for a VERY long time.
I suppose my question is--> why do tattoos fade over time? Do the
pigments break down over time, or do the colored pigments kill
their macrophages faster than the balck/green dyes? Don't know.
Oops. One other comment--> since macrophages are recognized as self,
nothing else is going to come along and get rid of them -- adds
to the permanency of the tattoo.
Never had a tattoo myself, but I did accidently jab the back of my
hand with a lead (madagascan clay & graphite ;>) pencil when I was
about 7 or 8 years old. 21 years later the black dot is still right
where I left the pencil lead--stuck inthe skin on the back of my hand.
Good luck, and I hope you get what you want,
R. E. Clopton Center for Urban and Public Health Entomology
septate at tamsun.tamu.edu Department of Entomology
Gregarines Texas A&M University (Gig'em Aggies!)
"I don't mind a parasite, but I object to a cut-rate one." - Mr. Rick
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