  Centaurus A, the closest active galaxy, has been detected from radio to
high-energy gamma-rays. The synchrotron radiation by extremely high energy
protons may be a suitable mechanism to explain the MeV to GeV emission detected
by the instruments of the Compton Gamma-Ray Observatory, as coming from the
inner jets. This scenario requires a relatively large magnetic field of about
10^4 G that could be present only close to the central black hole. We
investigate the spectral energy distribution (SED) resulting from a one-zone
compact acceleration region, where both leptonic and hadronic relativistic
populations arise.
  We present here results of such a model, where we have considered synchrotron
radiation by primary electrons and protons, inverse Compton interactions, and
gamma-ray emission originated by the inelastic hadronic interactions between
relativistic protons and cold nuclei within the jets themselves. Photo-meson
production by relativistic hadrons were also taken into account, as well as the
effects of secondary particles injected by all interactions. The internal and
external absorption of gamma rays is shown to be of great relevance to shape
the observable SED, which was also recently constrained by the results of HESS.
