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Old 11-10-2013
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Question Progestrone and LH

Can someone explain what is the relationship between Progestrone and LH ??
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Old 11-11-2013
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In the female body:

1- LH acts on Theca Interna cells to stimulate the conversion of Cholesterol to Andostrione via desmolase. Then, the FSH works on the Granulosa Cells to convert Andostrione to Estrogen via Aromatase.

So estrogen during the first half of the menstrual cycle causes negative feedback on the hypothalamus/pituitary which causes GnRH to pulse a certain way. However, once estrogen concentration rises, it causes GnRH to change its pulsation which causes a surge in LH.

The surge in LH causes ovulation (the dominant follicle ruptures and push the ovum into the Fallopian tube). As a result of this, Progesterone levels rise and Estrogen levels begin to fall. The result of this is that the endometrium stops proliferating (which is mediated by Estrogen) and it starts to become more vascular (I think), and is maintained at this size. However, once LH levels drop, which they eventually do, Progesterone decreases and this causes the loss of maintenance of the endometrium because of decreased Progesterone. This is when menstruation starts.

However, if the ovum is fertilized, it produces hCG which is very similar to LH. LH will drop regardless of whether or not there is pregnancy, so thats why hCG is required. hCG SIMULATES LH to STIMULATE Progesterone.
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The above post was thanked by:
alekkrish (03-16-2016)


Endocrine-, Physiology-, Reproductive-

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