Contractile function of the smooth-muscle wall and its adrenergic regulation in megaureter.

We demonstrated disordered contractile capacity of megaureters formed against the background of reflux, organic or functional obstruction. The rhythmic and tonic contractions were suppressed in the megaureters with organic obstruction in comparison with megaureters caused by reflux. Norepinephrine stimulation induced pronounced pressor responses in obstructive megaureters. The state of the smooth-muscle walls of megaureters with functional obstruction was characterized by high tone, weak phase contractions, and increased capacity to pressor tonic reactions induced by norepinephrine.