  We study the Regge trajectories and the quark-antiquark energy in excited
hadrons composed by different dynamical mass constituents via the gauge/string
correspondence. First we exemplify the procedure in a supersymmetric system,
D3-D7, in the extremal case. Afterwards we discuss the model dual to large-Nc
QCD, D4-D6 system. In the latter case we find the field theory expected gross
features of vector like theories: the spectrum resembles that of heavy
quarkonia and the Chew-Frautschi plot of the singlet and first excited states
is in qualitative agreement with those of lattice QCD. We stress the salient
points of including different constituents masses.
