  In recent years a tentative description of the short-range part of hadron
interactions with constituent quark interchange has been developed providing an
alternative approach to meson physics. Quark interchange plays a role, for
example, in the nucleon-nucleon ($NN$) phase-shifts and cross-section. In heavy
ion collision simulations at intermediate energies one of the main features is
the $NN$ cross-section in the collisional term, where in most cases it is an
input adjusted to the free space value. In this paper we introduce the quark
degrees of freedom to the $NN$ cross-section in the Vlasov-Uehling-Uhlenbeck
(VUU) model and explore the possibility that these effects appear in the
observables at lower energies.
