  We discuss the role of feedback from AGNs on the formation of spheroidal
galaxies. The energy released by an accreting Black Hole (BH) may be injected
into the ISM through blast waves arising directly from the central engine,
radiation pressure or radiative heating. A scenario is described in which
radiative heating perturbs the methabolism of a star-forming spheroid, leading
to a critical stage where SNe form a cold expanding shell, pushed out of the
galaxy by radiation pressure from the AGN. This mechanism can regulate the
BH--bulge relation to the observed value. However, this relation may be simply
imprinted by the mechanism responsible for the nearly complete loss of angular
momentum of the gas that accretes onto the BH. Using a novel model of galaxy
formation that includes AGNs, we show that models without self-regulation have
problems in reproducing the correct slope of the AGN luminosity function, while
models with winds give a much better fit; however, all these models are almost
indistingishable as far as their predicted BH--bulge relation is concerned.
Finally, we show that the downsizing of the faint AGNs is most likely due to
kinetic feedback in star-forming bulges.
