  We study the $\rho$-meson spectral function in hot nuclear matter by taking
into account the isospin-symmetric pion and the nucleon loops within the
quantum hadrodynamics (QHD) model as well as using an effective chiral SU(3)
model. The spectral function of the $\rho$ meson is studied in the mean field
approximation (MFA) as well as in the relativistic Hartree (RHA) approximation.
The inclusion of the nucleon loop considerably changes the $\rho$-meson
spectral function. Due to a larger mass drop of $ \rho $ meson in the RHA, it
is seen that the spectral function shifts towards the low invariant mass
region, whereas in the MFA the spectral function is seen to be slightly shifted
towards the high mass region. Moreover, while the spectral function is observed
to be sharper with the nucleon-antinucleon polarization in RHA, the spectral
function is seen to be broader in the MFA.
