Nobody knows this?

[finwon]

Advertisement - Members don't see this ad

I asked a question about the reproduction hormones and their negative feedback effects, but didn't get an answer.
Anyone knows?

I asked:

I know estrogen inhibits FSH secretion, but what about progesterone?

According to one of the Kaplan bio question, progesterone does NOT shuts off FSH production.

Is this correct?

In some bio books, it's unclearly stated that estrogen and progesteron secretion inhibits FSH and LH secretion.

Which one's correct?

Does estrogen or progesterone inhibit LH?

Thank you for your answer in advance

 

[phungy]

In Schaum's Bio Outline it says "One important effect of the high levels of progesterone is the suppression of follicular development in the ovary."

In Berkley Review it says: You need both progesterone and estrogen to have a negative feedback effect on LH and FSH in the anterior pituitary as well as hypothalamus and the making of GnRH. Estrogen at high levels has a positive feedback on LH. Estrogen at low levels has a negative feedback on FSH.

Please correct me if I'm wrong.

 

[blasterx]

In Schaum's Bio Outline it says "One important effect of the high levels of progesterone is the suppression of follicular development in the ovary."

In Berkley Review it says: You need both progesterone and estrogen to have a negative feedback effect on LH and FSH in the anterior pituitary as well as hypothalamus and the making of GnRH. Estrogen at high levels has a positive feedback on LH. Estrogen at low levels has a negative feedback on FSH.

Please correct me if I'm wrong.

I'm pretty sure that's right. Although I don't think it's necessarily high _levels_ of estrogen that cause positive feedback of LH, it's the length of time. Estrogen suppresses the release of LH initially, but after something like 36 hrs it positively effects LH secretion.