  We reinvestigate the $J/\psi$ dissociation processes induced by the reactions
with nucleons, $J/\psi + N \to \bar{D}^{(*)} + \Lambda_c$, in the
meson-exchange model. Main constraints used in this work are vector-meson
dominance and charm vector-current conservation. We show that the cross section
for $J/\psi + N \to \bar{D} + \Lambda_c$ can be larger than that for $J/\psi +
N \to \bar{D}^{*} + \Lambda_c$ when these constraints are imposed. The
dependence of the cross sections on the coupling constants is analyzed in
detail, and the comparison with the recent quark-interchange model predictions
is also made.
