A VERY DANGEROUS FORM OF ESTROGEN
What is going on here? Estrogen is a steroid hormone that acts during the menstrual cycle to prepare uterine and mammary gland tissues for possible pregnancy. It does this by by activating the appropriate parts of the chromosomal material (DNA) so that cell division and other necessary processes occur. The specific form of estrogen (called estradiol) that is normally secreted by the follicles that produce the egg cells acts on tissues in the uterus and mammary gland cells in a way that is normally well controlled. But there happens to be another form of estrogen called 16-hydroxyestrone that binds very tightly to the chromosomal material, causing the cell division process to become permanently locked so that it then procedes in a wildly uncontrolled manner.
The biochemical details of how 16-hydroxyestrone can be formed involve two breakdown pathways, a safe pathway, and a dangerously unsafe pathway. The important difference is whether a hydroxyl group gets put on the number 2 carbon atom, making it 2-hydroxyestrone or whether it gets put on the number 16 carbon
atom, making it the dangerously unsafe 16-hydroxyestrone:
