Why do so many mothers have difficulty making enough milk to breastfeed? A new study by scientists at Cincinnati Children's Hospital Medical Center and the University of California Davis adds to their previous research implicating insulin's role in lactation success.
The study is the first to describe how the human mammary gland becomes highly sensitive to insulin during lactation. It is also the first study to get an accurate picture of how specific genes are switched on in the human mammary gland during lactation.
The researchers used next generation sequencing technology, RNA sequencing, to reveal "in exquisite detail" the blueprint for making milk in the human mammary gland, according to Laurie Nommsen-Rivers, PhD, a scientist at Cincinnati Children's and corresponding author of the study, published online in PLOS ONE, a journal of the Public Library of Science.
Nommsen-Rivers' previous research had shown that for mothers with markers of sub-optimal glucose metabolism, such as being overweight, being at an advanced maternal age, or having a large birth-weight baby, it takes longer for their milk to come in, suggesting a role for insulin in the mammary gland. The new research shows how the mammary gland becomes sensitive to insulin during lactation.
For a long time, insulin was not thought to play a direct role in regulating the milk-making cells of the human breast, because insulin is not needed for these cells to take in sugars, such as glucose. Scientists now, however, appreciate that insulin does more than facilitate uptake of sugars.
"This new study shows a dramatic switching on of the insulin receptor and its downstream signals during the breast's transition to a biofactory that manufactures massive amounts of proteins, fats and carbohydrates for nourishing the newborn baby," says Dr. Nommsen-Rivers.
"Considering that 20 percent of women between 20 and 44 are prediabetic, it's conceivable that
|Contact: Jim Feuer|
Cincinnati Children's Hospital Medical Center