Getting breast milk to flow requires a soft touch

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Transcript of “Battling to breast feed ? Insulin resistance might be to blame”

insulin holng the keys in front of breast

Insulin gets breast milk production going, but, as hormones go, insulin is a bit of a bully, too much insulin leads to production troubles.

Breast feeding is best – so, you’re doing it. You’ve ensured that you don’t do anything to jeopardize the process,

You experienced the oxytocin serge of labour
You and your baby, experienced skin-to-skin contact in the delivery room and
Dummies and bottles, are not part of your baby retinue new one

But despite your commitment, you’ve run into difficulties.

The difficulty – there just doesn’t seem to be enough breast milk, to keep baby satisfied.

How come ?

Researchers from Cincinnati Children’s Hospital Medical Centre, have begun to piece together the mystery of why some women don’t have enough breast milk, by analysing which genes are involved in getting “milk to flow”.

“Operation milk”

Transforming breasts from an attractive appendage, to a fully functional milk factory, is a process and several hormones are involved in the development.

Prolactin is the chief engineer.

She kicks off the process with some serious remodelling, because the breast must first and foremost, be very grab-able, so that baby is able to latch on and tuck in. And next big enough, to keep baby fully supplied.

During the course of pregnancy, the necessary adjustments are made….

The nipple and areolar become larger
The ducts and alveoli are extended and
The blood supply is enhanced.

But, it is not just enough to have the machinery in place, the mammary gland has to step up production processes, so that it can produce large quantities of breast milk.

It seems, prolactin sub-contracts this job….

Turning on the milk machine

The first drops of breast milk, colostrum, are rather special – their release is orchestrated by oxytocin, the hormone in charge of labour. The uterus is not the only tissue, sensitive to oxytocin’s massaging …………… the mioepithelial cells in the breast tissue, also get pushing.

The first drops of milk, quite literally…………….leak out.

Squeezing through the not so tight, tight-junctions, which separate the breast epithelial cells from each other. But, moving the milk between cells is inherently inefficient and not sustainable. So, as the machine comes fully on-line, the milk is actively secreted, in an energy intensive process. New one

It typically takes a few days to get the milk production machine fully functional.

For most women, this happens around day 4 or 5 postpartum. At this point in time, breast engorgement peaks…………… Mom and baby then slip into a rhythm, where production perfectly matches consumption.

Peeking inside the factory

For years, scientists have wanted to peek inside the factory, to learn more about who is involved in the process and what goes wrong, when the machine fails to come on line properly.

Unfortunately, this was impossible to do………..

No Mom in their right mind, would allow scientists to chop out bits of breast tissue, to study gene expression.

But, technology has come to the rescue. The Cinncinati team were able to spy on what was happening inside the human milk factory, using RNA sequencing. You see, the mammary epithelial cells, who are doing the work, use RNA sequences to guide their production decisions.

And some of these RNA molecules end up in the milk…..

They don’t last very long, but if the scientist are quick, they can catch enough of them in a fresh milk sample to get a really good picture of what is going on.

The production guide

The team discovered, a staggering number of genes are involved in the process. In total, it takes 8817 genes to get the milk machine from dribbling out colostrum to real milk, but different genes are involved along the way.

The team identified three distinct phases.

Phase 1 (colostrum)

Involves the expression of genes that are important for immune defences. The proteins being produced during this phase, include isoferritins and cathepsins.

Phase 2 (transitional stage)

Involves the expression of genes that are setting up the production process, specifically genes that are part of the protein synthesis machinery.

Phase 3 (mature)

Is all about feeding baby – two “foodie” proteins dominate this phase : b-casein (CSN2) and a-lactalbumin (LALBA). Alongside these foodie proteins, many genes involved in lipid synthesis, also come on line.

It takes time….

Interestingly, the team found, women transitioned through these phases at different speeds, so day 3 milk in Mom number one, might be a little different from day 3 milk, in Mom number two.

This means many Moms who are battling to breast feed, might be calling it quits, too early………………

The flood gates only open when you hit phase 3.

The absence of copious amounts of milk, is because the factory is a little slow coming on line. It is a delay, not a failure. The milk is still coming……………….

Insulin the keeper of the keys

The team discovered that many of the genes being up-regulated, were taking their cue from insulin.

And, when production troubles arose……..insulin resistance was implicated.

Women who were insulin resistant, were slower to “fill up” – insulin sensitive women hit peak engorgement at 34 hours, while insulin resistant women, peaked around 74 hours.

Insulin resistant women, also had more trouble keeping the milk production go-ing.

“Genetically” speaking………………

Too much insulin

Moms who were insulin resistant, had altered expression of a specific gene, the PTPRF, during phase 3, of milk production.

PTPRF ?

I know, it is like alphabet soup…….

The PTPRF gene, makes an enzyme known as the protein tyrosine phosphatase enzyme – it’s job is to remove a phosphate group, from the amino acid tyrosine.

So what ?

It turns out, that this little enzyme is actually a key player in insulin resistance. The presence or absence of the phosphate group, impacts how responsive a cell is to insulin.

It seems, in women who are insulin resistant, the enzyme is working overtime in the breast tissue. It is trying to keep things in balance………….. compensating for the excess insulin.

Insulin is a bit of a bully…..