  For a compiled sample of disk galaxies with available photometry (B and K
bands), velocity line-widths and HI integral fluxes, several parameters which
trace the luminous, baryonic and dark matter contents were inferred. We
investigated how these parameters do vary with different galaxy properties, and
confronted the results with predictions of galaxy evolutionary models in the
context of the LCDM cosmogony. The ratio of disk-to-total maximum circular
velocity, vd/vt, depends mainly on the central disk surface density Sig_d (or
surface brightness, SB), increasing roughly as Sig_d^0.15. While a fraction of
high SB galaxies have a vd/vt ratio corresponding to the maximum disk solution,
the low SB are completely dark matter dominated. The trend is similar for the
models, although they have slightly smaller vd/vt ratios than observations. An
analysis of residuals of the vd/vt-Sig_d relation shows that vd/vt tends to
decrease as the galaxy is redder, more luminous (massive), and of earlier type.
The models allow us to explain the physics of these results, which imply a
connexion between halo structure and luminous properties. The estimated
dynamical-to-baryon mass and dynamical mass-to-light ratios at a given radius,
for observations and models, decrease with the SB and do not correlate with the
galaxy scale, contrary to what has been reported in previous works, based on
the analysis of rotation curve shapes. We discuss this difference and state the
importance to solve the controversy on whether the dark and luminous contents
in disk galaxies depend on SB or luminosity. The broad agreement between models
and observations favors the LCDM scenario. However, the excess of dark matter
inside the optical region of disk galaxies remains as the main difficulty.
(abridged)
