Estrogen influences the secretion of which of the following hormones?

• A. All of these
• B. Growth hormone
• C. Prolactin
• D. Luteinizing hormone

Answer: (A)

Estrogen acts on multiple points of the hypothalamic–pituitary axis, influencing several hormones, not just the reproductive ones. For LH, high estrogen levels from the dominant follicle provide positive feedback that increases GnRH signaling to the pituitary and promotes the midcycle LH surge needed for ovulation. For prolactin, estrogen lifts the inhibitory effect of dopamine on lactotrophs and also directly stimulates prolactin gene expression, so prolactin rises in states with high estrogen such as the late follicular phase and pregnancy. For growth hormone, estrogen modulates the balance of GHRH and somatostatin to the pituitary, enhancing pulsatile GH release, with pronounced effects during puberty and across the menstrual cycle. Because estrogen can influence all three, the best answer is that it affects the secretion of all of these.