Keith and Dalia Abrams wrote:
 If I understood correctly, the receptors are on the cells
> that synthesize milk, the alveoli? So, when breast involution occurs, eithe
> after weaning, or as baby gets to be a toddler and doesn't drink all that
> much at breast, do alveoli dissapear, along with their receptors?
After the prolactin receptors develop (by about 6 wks postpartum) and
baseline prolactin levels drop, milk synthesis is controlled by four
factors:
-blood level of prolactin, which spurts when baby begins sucking
-presence of stored milk (too much of a specific protein/peptide in milk
produces feedback inhibition) this is called autocrine control.
-ability of prolactin to get to the milk gland cells (too much stored
milk puts pressure on the vasculature of the breast, reducing the
ability of prolactin to get in)
-pressure deformation of milk gland cells causes the machinery to not
line up anymore, stopping it from functioning.

We think that autocrine control is most important during later
lactation, once it is well established.  This is how a toddler can nurse
once a day, and mom rarely feels engorged.  Involution seems to be
gradual when lactation is well established and the demand for milk falls
very slowly (like child led weaning) and rapid when the autocrine
control system is not mature yet and pressure builds up excessively (as
in those moms who quit cold turkey after a few days or weeks of bf).

Is a
> multipara starting out with the same nuber of receptors as a primip in the
> first phase of BF? What about if mom is tandem nursing? Would the amount of
> involution that has occured effect how many receptors are left?

We don't know.

>Actually, oxytocin receptors seem more relavent to the issue of
> after pains. Do you know where these are and how many???
Oxytocin receptors responsible for afterpains are on the uterus.  They
are the same ones responsible for labor.  Afterpains seem to be more
severe after each subsequent pregnancy.

> Just really curious
Me too, eternally

--
Catherine Watson Genna, IBCLC  New York City  mailto:[log in to unmask]

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