Final answer:
Anastrazole and Letrozole act by inhibiting the aromatase enzyme, leading to decreased estrogen synthesis. Antagonists that bind plasma membrane receptors for steroid hormones like testosterone would block the effects of these hormones.
Step-by-step explanation:
The mechanism of action of Anastrazole and Letrozole results in the inhibition of the aromatase enzyme. This action effectively reduces estrogen synthesis in the body by preventing the conversion of androgens into estrogens. This mechanism inhibits estrogen production, primarily in postmenopausal women, which is crucial in the treatment of certain types of breast cancers that grow in the presence of estrogen.
Effects of Steroid Hormone Antagonists:
Antagonist molecules binding to plasma membrane receptors, including those for steroid hormones like testosterone, would block the hormone from binding to its receptor. As a result, this blockade would prevent the downstream signaling and physiological effects that testosterone would normally mediate in the body.