Central effects of (5RS, 1'SR)-5-benzyl-3-(3'-morpholino-1'-phenylpropyl)-1,3-oxazolidin-2 -one monofumarate on the function of the bladder and periurethral skeletal muscle in anesthetized rats.

The effects of a newly developed drug for incontinence, (5RS, 1'SR)-5-benzyl-3-(3'-morpholino-1'-phenylpropyl)-1,3-oxazolidin-2- one monofumarate (NC-1800), on bladder and periurethral skeletal muscle functions were tested in urethane-anesthetized rats. When the bladder pressure was low, i.v. administration of NC-1800 at doses of 4 to 16 mg/kg induced dose-dependent increases of vesical pressure associated with increases in pelvic efferent nerve activity. When the bladder was expanded, the same administration of NC-1800 induced dose-dependent inhibitions of both vesical micturition contractions and rhythmic pelvic burst discharges. Hypogastric efferent nerve activity was not affected. The periurethral electromyogram (EMG) activity was excited when the bladder was contracted, and EMG activity was inhibited when the bladder was relaxed by NC-1800. Pelvic ganglionic transmission, neuromuscular transmission of both bladder and urethra, and muscle contractility itself of bladder and urethra were not affected by NC-1800. These results suggest that NC-1800 modulates the functions of the bladder and urethra by influencing pelvic and pudendal nerve activity via the central nervous system.