estradiol vs estrogen on LH and FSH levels
I had always thought that estrogen created a negative feedback loop to both the hypothalamus and anterior pituitary to prevent secretion of LH, FSH, and GnRH.
However, in Kaplan FL 3 Bio Question 47, the answer explanation said
Quote:
Estradiol has a positive feedback effect on the pituitary, causing it to secrete LH and FSH. Estradiol also has a positive feedback effect on the hypothalamus, causing it to secrete GnRH. Estradiol injection will lead to an LH surge in rodents capable of cycling.
Which is right? Estradiol is a type of estrogen so shouldn't it have a negative feedback and not a positive feedback?
Source: Student Doctor Network Forums - Category: Universities & Medical Training Authors: ihatebluescrubs Tags: MCAT Study Question Q&A Source Type: forums