Role of dopamine in the pathogenesis of hypertension

1. Dopamine, via different dopamine receptor subtypes, regulates cardiovasc ular functions by actions on the central and peripheral nervous systems, va scular smooth muscle, the heart anal the kidney, The dopaminergic system in the central nervous system (CNS) may participate in the regulation of syst emic blood pressure, 2. Dopamine 'D2-like' (D2, D3 and D4) receptors, rather than 'D1-like' (D1 and D5) receptors, are involved in the CNS regulation of blood pressure; po st-synaptic D2-like receptors increase blood pressure, while presynaptic D2 -like receptors (the predominant action) produce the opposite effect, 3. Outside the CNS, dopamine may regulate blood pressure via pressure contr ols that art with intermediate sapidity (e.g. stress relaxation, arginine v asopressin and renin-angiotensin vasoconstriction), as well as those system s related to the longterm control of body fluid volume. 4. Dopamine D1- and D2-like receptors have been described in resistance ves sels, such as the renal, mesenteric, coronary, pulmonary and cerebral arter ies, The ability of D1-like receptors to inhibit renal smooth muscle hypert rophy indicates their importance in longer-term regulation of blood pressur e. 5. Aberrant dopaminergic regulation of aldosterone secretion via D2-like re ceptors, has been reported to be involved in some forms of hyperaldosteroni sm and hypertension, Some forms of hypertension may also be caused by an ab errant renal dopaminergic system. Abnormalities of three aspects of the ren al dopaminergic system may lead to hypertension: (i) renal production of do pamine; (ii) transduction of the renal vascular dopamine signal; and (iii) transduction of the renal tubular dopamine signal. 6. Thus, increased blood pressure occurs after either blockade of D1-like r eceptors or of dopamine production in rats or disruption of the D1 receptor or the D3 receptor gene in mice.