I have been following the MER thread with interest.  A sentence of Lisa
Marasco's message about the physiology of the MER (oxytocin and prolactin
receptors in the breast) jumped out at me because I am slowly trying to
piece together information on the elusive implications of progestin-only
pills on lactation.  Lisa wrote, "Like milk production issues, I do wonder
if there comes a point of "no return" when too many receptors have died off
and the response to suckling is limited.  I also wonder what, if any, other
factors might affect the development and maintenance of oxytocin receptors,
as I have recently learned that *prolactin receptors can be "down-regulated"
by excess male hormones*" (my emphasis).

Lisa, in my quest for more knowledge about a hormonal contraceptive which
contains norgestrel I have learned that this synthetic progesterone has
"androgenic activity".  If prolactin receptors can be down-regulated by
excess male hormones, could this be another piece of the puzzle in the POP
story?  Can you elaborate?  And do you have a journal reference, please?

Pamela, Zimbabwe