  Pressure sensitivity (up to 1 GPa) of the electrical resistivity and of the
ac susceptibility was measured for low electron doping levels of
Ca$_{1-x}$Y$_x$MnO$_3$ (CYMO) and of Ca$_{1-x}$Sm$_x$MnO$_3$ (CSMO) ceramic
samples (0.05 $\leq$ x $\leq$ 0.15). A very weak pressure dependence of the
Curie temperature (T$_c$) was observed for both systems ($\sim$ 6 K
GPa$^{-1}$), when compared to the hole-doped manganites of the same T$_c$
($\sim$ 20 K GPa$^{-1}$). Our results can be interpreted within a modified
Double Exchange scenario, where pressure alters the reduction of the bandwidth
produced by the electron-phonon interaction associated with small Fr\"{o}hlich
polarons in the weak to intermediate coupling regime.
