Contractile effects of stimulation of D₁-dopamine receptors in the isolated human atrium.

ABSTRACT: Dopamine receptors have been claimed not to directly increase contractility in the human heart. Therefore, we performed contraction experiments in isolated electrically driven human atrial preparations (HAP). For comparison, we performed contraction experiments with left atrial preparations of transgenic mice which harbor a cardiac overexpression of human D₁-dopamine receptors (D₁-TG). In D₁-TG, first we noted that dopamine (10 nM-10 µM cumulatively applied) in the presence of propranolol exerted a concentration- and time-dependent positive inotropic effect in D₁-TG. In a similar fashion, dopamine increased force of contraction in the presence of 0.4 µM propranolol in HAP and these effects were amplified by pre-treatment with inhibitor of phospho

SUBMITTER: Gergs U 

PROVIDER: S-EPMC11825631 | biostudies-literature | 2025 Feb

REPOSITORIES: biostudies-literature