The equation for the superconducting transition temperature has been obtained using the Hubbard-Stratovich method to eliminate Coulomb repulsion and local attraction between electrons. The equation includes the dynamically screened Coulomb interaction in a two-band model with “light” and “heavy” carriers. The dynamical screening is shown to lead to a reduced Coulomb pseudopotential for the “light” carriers responsible for pairing proportional to the inverse mass of “heavy” particles.