The impairment of sympathetic innervation of the urinary bladder neck was supposed to be a cause of the syndrome of diabetic retrograde ejaculation (DRE). The performance of the sphincter system had not been studied in this category of patients. The liquid profilometric technique was used to examine 3 groups of males: 8 patients with the DRE syndrome; 5 patients with diabetes mellitus (DM) without ejaculation disorders; and 7 apparently healthy subjects. All the examinees showed no organic changes in the prostate and urethra. The groups were matched by age, type, duration and severity of DM. The DRE syndrome patients had no elevation of intraureteral pressure in the area the inner sphincter of the urinary bladder, which evidenced its atony. In health the elevation of vesical pressure is usually accompanied by an increase in ureteral resistance (r = 0.96; p less than 0.001), thus maintaining the stability of the positive pressure gradient and preventing the escape of urine. Correlation analysis revealed alterations of interrelations between intravesical and sphincter pressures in diabetes mellitus patients. This phenomenon evidenced the disorders of somatic innervation of the outer ureteral sphincter more pronounced in patients with the DRE syndrome. No significant differences were revealed in the length of the anatomical and functional ureter as well as in the length of the posterior ureter of all the patients involved in the study.(ABSTRACT TRUNCATED AT 250 WORDS)