> I'm looking for references for the theory that there are suppressor
> peptides produced in the breast when milk is stagnant, not removed
> thoroughly and frequently.

I have always liked this "theory" because it made so much sense, but Peter
Hartmann told us a few months ago at the NMAA Conference that his recent
research has been unable to support the peptide theory in humans.  He now
thinks the suppressor factor may be the build up of pressure in the
ducts/alveolae as milk volume  increases. This too makes sense. I don't
think he has published on this yet so can't give a reference.