  We study theoretically single electron loss from helium-like highly charged
ions involving excitation and decay of autoionizing states of the ion. Electron
loss is caused by either photo absorption or the interaction with a fast atomic
particle (a bare nucleus, a neutral atom, an electron). The interactions with
the photon field and the fast particles are taken into account in the first
order of perturbation theory. Two initial states of the ion are considered:
$1s^2$ and $(1s2s)_{J=0}$. We analyze in detail how the shape of the emission
pattern depends on the atomic number $Z_{I}$ of the ion discussing, in
particular, the inter-relation between electron loss via photo absorption and
due to the impact of atomic particles in collisions at modest relativistic and
extreme relativistic energies. According to our results, in electron loss from
the $1s^2$ state autoionization may substantially influence the shape of the
emission spectra only up to $Z_{I} \approx 35-40$. A much more prominent role
is played by autoionization in electron loss from $(1s2s)_{J=0}$ where it not
only strongly affect the shape of the emission pattern but also may
substantially increase the total loss cross section.
