Estrogen and Progesterone negative feedback

[pm1]

Estrogen and Progesterone has a negative feedback on the anterior pituitary or hypothalamus? I've seen info talking about both.

---

Members don't see this ad.

 

[MedPR]

Estrogen and Progesterone has a negative feedback on the anterior pituitary or hypothalamus? I've seen info talking about both.

Both. Do you have a more specific question?

 

[pfaction]

Stops GnRH @ Hypo, FSH/LH @ pit.

 

[pm1]

Both. Do you have a more specific question?

No. I was just wondering because I've seen questions talking about both.
Thank you!!

 

[SaintJude]

I have the Kaplan book that has a chart on the feedback process. Like pfaction said, estrogen feedsback at hypo and progesterone at anterior pituitary.

Estrogen feedbacks on hypothalamus.
Estrogen feeds negatively back on the hypothalamus early in the cycle (to prevent multiple egg development). But estrogen also feeds back positively later in cycle. (found that curious)

Progesterone feeds back on the anterior pituitary
Progesterone feeds negatively back on the anterior pituitary (to ↓ LH) after the LH surge to prevent development of multiple follicles.

 

[chiddler]

I have the Kaplan book that has a chart on the feedback process. Like pfaction said, estrogen feedsback at hypo and progesterone at anterior pituitary.

Estrogen feedbacks on hypothalamus.
Estrogen feeds negatively back on the hypothalamus early in the cycle (to prevent multiple egg development). But estrogen also feeds back positively later in cycle. (found that curious)

Progesterone feeds back on the anterior pituitary
Progesterone feeds negatively back on the anterior pituitary (to ↓ LH) after the LH surge to prevent development of multiple follicles.

Estrogen only feeds positively above some threshold during ovulation. After that phase has passed, it continues to feed back negatively which is why when the corpus luteum regresses, FSH bumps up again. So it might be misleading to say "later", but rather middle or during ovulation.

&#8595;&#8595;&#8595; <-- nice

 

[Temperature101]

Reproduction with these hormonal interactions is a difficult subject for me no matter how much I study it.

 

[Medical Muse]

Estrogen normally has negative feedback on the hypothalamus and pituitary, but right before the LH surge and ovulation, the feedback switches from negative to positive (we still don't know exactly why). Progesterone then causes the LH levels to decrease through its negative feedback on the hypothalamus and pituitary.

 

[Temperature101]

Estrogen normally has negative feedback on the hypothalamus and pituitary, but right before the LH surge and ovulation, the feedback switches from negative to positive (we still don't know exactly why). Progesterone then causes the LH levels to decrease through its negative feedback on the hypothalamus and pituitary.

I thought it switches from positive to negative right before LH surge and ovulation because Estrogen act positively on GnRH, which in acts to the anterior pituitary to increase LH before ovulation. May be I got it backwards... Can someone else chime on that?

 

[MedPR]

I thought it switches from positive to negative right before LH surge and ovulation because Estrogen act positively on GnRH, which in acts to the anterior pituitary to increase LH before ovulation. May be I got it backwards... Can someone else chime on that?

If it switched from positive to negative right before the LH surge, the LH surge wouldn't happen. Negative feedback inhibits LH secretion, positive feedback stimulates LH secretion (as in the LH surge).

 

[Temperature101]

If it switched from positive to negative right before the LH surge, the LH surge wouldn't happen. Negative feedback inhibits LH secretion, positive feedback stimulates LH secretion (as in the LH surge).

I meant right after LH surge

 

[MedPR]

I meant right after LH surge

Oh, well I guess it might switch back to negative feedback post-ovulation, but I don't know for sure. Just prior to the LH surge, estrogen has a positive feedback effect on LH. At all points prior to that, estrogen has a negative feedback so I assume that right after the LH surge it switches back to neg feedback.

 

[chiddler]

Oh, well I guess it might switch back to negative feedback post-ovulation, but I don't know for sure. Just prior to the LH surge, estrogen has a positive feedback effect on LH. At all points prior to that, estrogen has a negative feedback so I assume that right after the LH surge it switches back to neg feedback.

Yes, it does.

 

[MrNeuro]

Oh, well I guess it might switch back to negative feedback post-ovulation, but I don't know for sure. Just prior to the LH surge, estrogen has a positive feedback effect on LH. At all points prior to that, estrogen has a negative feedback so I assume that right after the LH surge it switches back to neg feedback.

Yes, it does.

remember though that its not just the estrogen acting after the LH surge its both estrogen and progesterone working together to inhibit LH production via what everyone else said above (LH and GnRH inhibition @ ant pit and hypo respectively)