Rajnee, Sunita Choudhary, Bijendra Kumar Binawara.
Short review of pathophysiology of catechol estrogen.
Pak J Physiol Jan ;6(2):60-2.

In women of reproductive age, the primary source of circulating estrogens is the ovaries. There are three forms of estrogen circulating in our bloodstream: estradiol, estrone and estriol. The normal ratio of these three types of estrogens ideally should be 10– 20%, 10–20%, and 60–80% respectively. The estrogen that accounts for most of the tissue stimulation is called estradiol. Estrone is a little bit less potent with estriol being the weakest. Brain converts estrone and estradiol to 2- and 4- hydroxylated derivatives known as catechol estrogens.

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