  Using the self--consistent Hartree-Fock approximation for electrons with spin
at zero temperature, we study the effect of the electronic interactions on the
charge distribution in a one-dimensional continuous ring containing a single
$\delta $ scatterer. We reestablish that the interaction suppresses the decay
of the Friedel oscillations. Based on this result, we show that in an infinite
one dimensional conductor containing a weak scatterer, the current is totally
suppressed because of a gap opened at the Fermi energy. In a canonical ensemble
of continuous rings containing many scatterers, the interactions enhance the
average and the typical persistent current.
