Table 1

Actions of Vasopressin

ReceptorSignalingLocationActions
V1aG-protein, IP3Blood vesselsVasoconstriction
MyocardiumInotrope/mitogen
V2Adenyl cyclaseRenal tubuleH2oretention
EndotheliumVasodilation (high concentrations)

The predominant actions of vasopressin as relates to heart failure involve activation of the V1a and V2 receptors. See text for details.