  The effects of rotation on low-metallicity stellar models are twofold: first,
the models reach break-up during main sequence and may lose mass by mechanical
process; second, strong internal mixing brings freshly synthesized elements
towards the surface and raises the effective metallicity to higher values, so
that the initially very low radiative winds are enhanced. Those two effects are
also found in Z=0 models, but to a lesser degree because of structural
differences. This weak mass loss becomes interesting though in the case of the
black hole-doomed stars (25-140 M_\sun and > 260 M_\sun) because it allows
these stars to contribute to the enrichment of the medium by stellar winds.
