[The experimental evaluation of the difference in closing dynamics of internal urethral ostium on the urinary continence and on the ejaculation induced by an administration of phenylephrine].

BACKGROUND

The internal urethral ostium is usually closed both on the ejaculation and on the urine collection, although the difference of the closing characteristics have not been known.

METHODS

The difference in closing style of bladder neck (internal urethral ostium) between on the phenylephrine administration corresponding state to the ejaculation and on the filling of urinary bladder corresponding state to the urinary continence was evaluated by Stereo-UPP method using mongrel dogs.

RESULTS

On phenylephrine administration, the length between verumontanum and bladder neck was lengthened, and a remarkable pressure increase was observed in the area. On the urinary continence filling physiological saline in the bladder, the length of the urethra on the UPP curve of the anterior wall of urethra was lengthened (10%) and the base of bladder was gradually become flat. The pressure in the bladder neck was not relatively increased.

CONCLUSIONS

The internal urethral ostium was closed both on the phenylephrine administration and on the urine collection, although the closing characteristics of each was very different. It was demonstrated that on the phenylephrine administration the area between the verumontanum and the bladder neck was lengthened, together with the rise of pressure in the area, whereas on the urine collection bladder neck was closed in low pressure by flattening the base of bladder.