[en] We have detected HCO⁺ emission toward the nucleus of NGC 253. The line profile similar to those of CO and HCN emission from this source. The ratio of integrated HCO⁺ and HCN intensities is essentially unity, similar to the value seen in M82 and in typical Galactic giant molecular clouds. Also, we have obtained null results for HCO⁺ emission in several other galaxies and for HNC emission toward M82. We discuss the potential significance of HCO⁺ observations as measurements of cosmic-ray densities within and among galaxies