  We report normal-state transport properties of the single-crystalline samples
of the silver-lead oxide superconductor Ag5Pb2O6, including the electrical
resistivity, magnetoresistance, and Hall coefficient. From the Hall coefficient
measurement, we confirmed that the carrier density of this oxide is as low as
5x10^{21} cm^{-3}, one order of magnitude smaller than those for ordinary
alkali metals and noble metals. The magnetoresistance behavior is well
characterized by the axial symmetry of the Fermi surface and by a single
relaxation time. The T^2 term of the resistivity is scaled with the specific
heat coefficient, based on the recent theory for the electron-electron
scattering. The present results provide evidence that Ag5Pb2O6 is a
low-carrier-density three-dimensional electron-gas-like system with enhanced
electron-electron scatterings.
