Abstract. HI absorption measurements against strong continuum background sources are an excellent tool to study the cold ISM in the line of sight to the object (e.g. pulsars, galaxies, quasars). Here we present a brief overview of such studies against the nuclear region of starburst galaxies. The high angular resolution provided by synthesis telescopes allows us to resolve the central region of nearby galaxies and thus investigate the gas kinematics close to the nucleus. The detection of fast-rotating nuclear rings is related to the bars in these galaxies which in turn might have been triggered by tidal galaxy-galaxy interactions.
Keywords. galaxies: individual (NGC 253, NGC 660, NGC 1511, NGC 6215, NGC 6221, NGC 7552, NGC 7582) - galaxies: starburst, barred, nuclear rings - galaxies: interaction.