Prostate gland is sensitive to different hormonal actions and is able to absorb selectively male and female sex hormones. Here binding of androgens occurs in androgen-dependent part of prostate gland and binding of estrogens occurs in estrogen-dependent part.
Androgens in prostate gland are not accumulated, instead they are rapidly transformed. Estrogens remain mainly unchanged. Steroid hormones of all classes are transported via blood plasma in form of protein complex. Blood contains estradiol. It binds beta globulin and is able to bind steroids having hydroxyl. Unlike peptidic hormones, which act on level of external cell membranes, steroid hormones enter cells and do bind with specific protein receptor congenerous; with this steroid.
It is not established yet how do sex hormones enter the target- cells. Partially is important a simple diffusion due to positive gradient of concentration. However, this is not main way of entering. There was obtained data about mechanisms of specific transportation of steroid hormones into prostate gland cells.
With the help of mechanism, which is based on binding steroids with surface of specific carrier, testosterone may be transported against gradient of concentration in higher amounts than are usually found in male blood. A binded steroid penetrates from cytoplasm in nucleus where it reacts with chromatin and DNA, induces synthesis of messenger RNA and amenable ferment proteins responsable for hormone properties.