subject: exons

Prolactin: One Hormone, Many Effects

Prolactin: One Hormone, Many Effects

Hormones are the body’s bike messengers, carrying important information from the endocrine glands (e.g., thyroid, pituitary, ovaries) to tissues throughout the body. Whereas GPS helps bike messengers find their intended recipients, hormones know they have found their target tissue when they are able to bind to hormonal receptors attached to a cell’s surface. Like a key fitting into a lock, hormones only bind to their specific receptor. Turning the key and opening the receptor’s lock allows the hormone to deliver its message to the cell, which responds by taking a particular action. The lactation hormone prolactin (PRL) has more than one target tissue, with prolactin receptors (PRLR) found in mammary glands, intestines, kidneys, ovaries, and even the heart. Mammary gland cells respond to PRL’s signal by secreting milk and initiating lactation, whereas cells of the intestines respond by increasing their absorption of calcium. How does the same hormonal signal result in the delivery of such different messages? Read More...