Frankie Say Relaxin! Hormonal Signals from Mother's Milk
Getting the Message via Milk We can imagine hormones are like a Facebook status post. Just as a Facebook status will only show up in the newsfeed of certain friends (I still don’t get the FB algorithm for this), hormone messages are only received by tissues that have the right receptors. In this way, specialized glands secrete a hormone to convey the body’s “status,” and the “friended” tissues—those with the receptor—are updated. This is known as the endocrine system. “Endo” of course is a Latin derivative meaning ‘within’ our own bodies. Images from Purves et al., Life: The Science of Biology, 4th Edition But what about hormones we get from someone else… like from our mother through her milk? This system is clearly not endocrine… the hormones are coming from another body via her mammary glands during lactation. For this reason they are termed “lactocrine” and the numerous bioactives in milk, including proteins, peptides, and steroids, might be messages from mother to baby. when I was