Depressed respiration induced by intravenously administered dopamine in anesthetized dogs.

Dopamine has increasingly become the drug of choice for treating patients with cardiogenic shock (1, 2). Numerous studies on the cardiovascular actions of dopamine revealed that dopamine itself has a specific action, which is distinct from its stimulating actions on α- and β-adrenergic receptors (3). This action is associated with specific dopamine receptors, except for those in the central nervous system, which exist mainly in the renal and mesenteric vascular beds. The specific action of dopamine is partly antagonized by haloperidol or chlorpromazine (3). In contrast, there are relatively few reports concerning the respiratory actions of dopamine. In our studies we found that exogenous dopamine was a transient but potent depressant of respiration in anesthetized dogs. Dopamine therapy in the treatment of shock is a comparatively new maneuver, and the therapeutic value and adverse effects are still open to assessment. Using anesthetized dogs, the respiratory and cardiovascular effects of dopamine, especially as a depressant of respiration, were examined. The current concepts of dopamine as an inhibitory modulator in respiratory control were then studied.