Why does dobutamine act on beta 1 receptor on renal vessels?

All over the body: Because doputamine acts on beta receptors all over the body. And Dobutamine is a partial vaso dilator, it decreases systemic vascular resistance, svr. It can mediate sympathetic nerve activity.

It is an agonist: Dobutamine is a b1 receptor agonist, b1 receptors are located throughout the body. It stimulates viscous, amylase-filled secretions from salivary glands, increase cardiac output, increase heart rate in sinoatrial node (sa node) (chronotropic effect), increase atrial cardiac muscle contractility. (inotropic effect)increases contractility and automaticity of ventricular cardiac muscle.