Those Binding to the Steroid Hormone Receptors

The system of male hormones, androgens, can also be subject to disrnption by some compounds. Such compounds include DDE (a DDT metabolite mentioned earlier) and some esters of phthalic acid. However, whether the esters of phthalic acid are indeed endocrine disruptors is still being investigated. 

2 Those Affecting AH Receptor and Cytochrome-P450 Enzymatic Systems 

Dioxin, PCB, DDT, and the like, i.e., chlorinated aromatic hydrocarbons are believed to bind to a special receptor called AH receptor (AH stands for aryl hydrocarbon). The AH receptor bound with dioxin (or PCB) enters into the nucleus of the cell, and binds to a specific site of a DNA. One of the effects caused by such a binding seems to be an induction of an enzyme dependent on cytochrome P-450. Cytochrome P-450-dependent monooxygenase was talked about in Sect. 6.2.2, and is involved in the metabolism of a wide variety of compounds including steroids and foreign substances (drugs). Probably the P-450 enzymes induced by dioxin, PCB, and others would then metabolize steroid hormones unnecessarily, and thus disrupt the endocrine system. The details are still not very well understood. However, you see that the processes are all chemical reactions at the deepest level. 

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