This unusual magnetization dynamics is due to the combination of two competing effects, namely, the coupling of the nuclear spins to the detection circuit that generates a radiation feedback field that drives the magnetization back to the +z direction, and known as radiation damping (RD); and an antagonist process that allows to rebuild polarization towards a negative value. In this work, the latter is provided by DNP, when negatively polarized nuclear spins are repolarized by electron spins and possibly also by other nuclear spin species that are also DNP-hyperpolarized but uncoupled to the NMR probe. In this case, the latter nuclear spins represent a reservoir of polarization that is indirectly transferred to the 1 H spins through their interactions with the electron spins.