International Board of Certified Lactation Consultant (IBCLC) Practice Exam

Is galactopoiesis primarily under autocrine or endocrine control?

1. Endocrine

2. Autocrine

3. Neural

4. Both endocrine and autocrine

The correct answer is: Autocrine

Galactopoiesis, the process of maintaining milk production after it has been established, is primarily under autocrine control. This means that the signals that regulate milk production predominantly originate from the milk itself, particularly from components produced by the alveolar cells in the mammary gland. As milk accumulates in the breast, it exerts a feedback mechanism through hormones and growth factors, such as prolactin and insulin-like growth factors, which are secreted by the mammary tissue in response to the needs of the infant. In autocrine regulation, the cells respond to substances that they themselves produce. During galactopoiesis, the milk components like lactose and fat act on the mammary epithelial cells to promote continued milk synthesis and secretion. Therefore, the autocrine signals created by the cells play a crucial role in sustaining milk production in a way that effectively meets the infant's demands. While endocrine factors, such as certain hormones, do play a role early in lactation and in initiating milk production, the maintenance phase is predominantly characterized by this autocrine feedback loop. The specific nature of this control highlights the importance of local factors over distant signals in the regulation of ongoing lactation.