In physiological conditions, dopamine mainly inhibits the prolactin (PRL) secretion from lactotroph cells [5, 11], but it also regulates hormone secretion from non-lactotroph cells, mainly through the activation of D2 receptor [5, 12, 13], whereas, in pathological conditions, the expression of DRs in several types of hormone-secreting, or functioning, as well as non-functioning, pituitary tumours represents the prerequisite for the employment of DAs, mainly bromocriptine (BRC) and cabergoline (CAB), in the management of different diseases associated with the pituitary tumours [14–17]. This evidence concerns the gene PRL and pituitary tumor.