  Optical emission-line profiles were evaluated in order to explore the
structure of galactic nuclei containing H2O megamaser sources. Galactic
rotation and outflow of narrow-line gas are common features of this sample of
water megamaser galaxies. All decomposed line-systems exhibit AGN typical line
ratios. Recent detections of H2O megamasers in starburst galaxies and the
apparent asssociation of one megamaser with a Seyfert 1 AGN suggest that
megamasers can possibly be triggered by optically detectable outflows. The
frequently encountered edge-on geometry favoring large molecular column
densities appears to be verified for NGC 1386 and IC 2560. For NGC 1052 and Mrk
1210, maser emission triggered by the optically detected outflow components
cannot be ruled out.
