Evidence for a role of dopamine in cardiac function

Experiments were carried out to further investigate the possibility that dopamine may have a functional role in the heart. Measurement of the activity of the enzyme tyrosine hydroxylase showed that this enzyme was present both in control hearts and in tissue with total sympathetic denervation. Furthermore, radioligand binding studies showed that there are high-affinity binding sites for dopamine in both control and denervated hearts. Our results support the view that there is dopamine in the heart which is not associated with noradrenergic nerves.