The present invention relates to acylamino-substituted heteroaromatic
compounds of formula I, ##STR00001## wherein R.sup.1, R.sup.2, R.sup.3,
R.sup.4 and R.sup.5 and X are as defined herein, to pharmaceutical
compositions comprising such compounds, to methods for the stimulation of
the expression of endothelial NO synthase, and methods of treatment
comprising administering such compounds.