  In this work the influence of the post-Newtonian corrections to the equations
of stellar structure is analysed. The post-Newtonian Lane-Emden equation
follows from the corresponding momentum density balance equation. From a
polytropic equation of state the solutions of the Lane-Endem equations in the
Newtonian and post-Newtonian theories are determined and the physical
quantities for the \textit{Sun}, for the white dwarf \textit{Sirius B} and for
neutron stars with masses $M\simeq1.4M_\odot, 1.8M_\odot$ and $2.0M_\odot$ are
calculated. It is shown that the post-Newtonian corrections to the fields of
mass density, pressure and temperature are negligible for the \textit{Sun} and
\textit{Sirius B}, but for stars with strong fields the differences become
important. For the neutron stars analysed here the central pressure and the
central temperature which follow from the post-Newtonian Lane-Emden equation
are about fifty to sixty percent greater than those of the Newtonian theory and
the central mass density is about three to four percent smaller.
