ABSTRACT
Dopamine is a biogenic amine synthesized in the hypothalamus, in the arcuato and caudate nuclei and in several areas of the central peripheral nervous system. It has been widely established that dopamine and its agonists play an important role in cardiovascular, renal hormonal and central nervous system regulation through stimulation of alpha and beta adrenergic and dopaminergic receptors. There are several agonists of DA2 dopaminergic receptors such as: bromocriotine, pergolide, lisuride, quinpirole, and carmoxirole, which inhibit nerepinephrine release, and produces a decrease of arterial blood pressure and, in some cases, bromocriptine and pergolide reduce heart rate. From a therapeutical point of view, the abone mentined agonists are used for treatment od Parkinson's disease, acting on DA2 dopaminergic receptors of the nigrostriatal system. Bromocriptine and the other domaminergic agonists mentioned act on DA2 receptor of the tuberoinfundibular system inhibiting prolactin release, decreasing hyperprolactinemia and tumor size. Among DA1 receptor agonists we can mention: fenoldopan, pirebedil, ibopamine, SKF 3893, apomorphine (non specific). Activation of these receptors decreases peripheral resistance and reduces arterial blood pressure, increases heart rate and sympathetic tone and the renin aldosterone system activity. Among DA2 receptor antagonists we can mention: metoclopramide, domperidone, sulpiride and haloperidol. From a therapeutic point of view, metoclopramide and domperidone are used in gastric motility disorders and haloperidol in psychotic alterations. Antagonists of DA1 receptors are: SCH23390 and clozapine. Clozapine is used for traating schizophrenia