[Q]What is PMA converted to ?

David L. Haviland, Ph.D. dhavilan at IMM2.IMM.UTH.TMC.EDU
Thu Feb 6 14:23:01 EST 1997


At 06:06 2/6/97 -0800, Hisanori Yamamoto wrote:
>
>In commercial technical sheets or technical advicing books,
>it is mentioned that PMA (phorbol myristate acetate) is not stable agent and 
>its carcinogenic efficiency reduces gradually in DMSO.
>
>What is PMA converted to ?
>Is PMA-derivative stable ?
>What is its effect as a drug?

Yamamoto:

That is news to me.  I won't argue with technical sheets, but I have been
using a TPA (PMA) stock in DMSO that is about 2 years old.  From what I can
tell, I see no visible or biological loss of activity in stimulating U937
or HL-60 cells at 50-100 ng/ml.

I'm splitting hairs, but I take exception to the technical sheets use of
"carcinogenic".  TPA is a tumor promoter (the most potent one), it, in of
itself is not carcinogenic and will not produce tumors without first
applying some initiator.

A more water soluble TPA analogue is phorbol-dibutyrate.  Non-specific
binding is minimal and it is almost as biologically as activte as TPA.

Hope this helps,
David

=============================
 David L. Haviland, Ph.D.
 Asst. Prof. Immunology 
 University of Texas - Houston, H.S.C.
 Institute of Molecular Medicine  
 2121 W. Holcombe Blvd.  
 Houston, TX  77030 
 Internet:"dhavilan at imm2.imm.uth.tmc.edu" 
 Voice: 713.500.2413  FAX: 713.500.2424
 ------------------------------------------------------  
" Sometimes you're the windsheild, sometimes you're the bug."
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