When electrical components are combined, quantum mechanics can affect even the simplest rules of electrodynamics such as the addition of series impedances when one component involves quantum transport. In this situation, the transfer of electrons across the element is associated to the creation of excitations in any series impedance, resulting in inelastic electron tunneling and hence in the so-called zero-bias anomaly of the conductance. For low series impedances, the excitation of the series impedance by the shot noise of the quantum element is at the origin of this Dynamcial Coulomb blockade of the conductance, as demonstrated by experiments in break junctions and quantum point contact. One important question now arises: what is the general relation between the current shot noise and Dynamical Coulomb Blockade ? Is there a Coulomb blockade of shot noise?

To investigate this question, we have embedded a tunnel junction in a microwave resonator which implements a "single-mode" electromagnetic environment, with a charcarateristic impedance large enough to observe DCB corrections to the conductance of the junction and to its the shot noise, well described by a recent theory.