Effect of esophagus distention on urinary bladder function in rats

Micturition process is a spinobulbospinal reflex that is affected by the viscero-visceral interactions due to convergent inputs into spinal and/or supraspinal centers controlling that reflex. Although interaction between bladder and other pelvic organs, such as colon, are well studied, the viscero-visceral interaction between urinary bladder and internal organs in other regions are rarely studied.

In the present study, continuous filling cystometry recordings, in male rats, were used to investigate the effects of mechanical stimulation of distal-esophagus (distention), as well as, electrical stimulation of abdominal branches of the vagus nerve on urinary bladder micturition cycles.

Distal esophagus distention and electrical stimulation of the vagus nerve significantly increased the micturition frequency through decreasing the time of the storage phase of the micturition cycle. However, bilateral cervical vagotomy eliminated the effects of distal esophagus distention and electrical stimulation of vagus nerve on micturition cycles.

The results of this study indicate that there is a viscero-visceral interaction between esophagus and urinary bladder, which is mediated through vagal afferents. Understanding the properties of the viscero-visceral interactions affecting the urinary bladder will help in the diagnosis and management of micturition problems.