<prompt> Prolactin:Has somatotropic activity.It flow can cause infertility in women.Can suppress menstrual cycle in lactating women.Levels are increased by dopamine.  <response>: Prolactin, though structurally related to growth hormone does not share its somatotropic activity. Dopamine binds to the lactotropes and inhibits the synthesis and release of prolactin. Hyperprolactinemia suppresses the hypothalamic-pituitary-gonadal axis, causes infertility in women and suppresses the normal menstrual cycle in lactating women. 