Role of urothelial nerve growth factor in human bladder function.

AIMS: To test whether nerve growth factor (NGF) concentration in human bladder urothelium/suburothelium is related to detrusor overactivity (DO), bladder sensation, detrusor contractility, or other aspects of lower urinary tract function.

MATERIALS AND

METHODS

Concentration of NGF was measured (using ELISA) in superficial bladder biopsies from 27 women (mean age 52 years, range 22-82) after comprehensive video-urodynamics and bladder diary. Approximately half (12/27) showed clear DO and half did not.

RESULTS

There was no evidence for increased NGF concentration in subjects with DO (association negative by Mann-Whitney test, P = 0.23). NGF was not significantly associated with two measures of detrusor contractility (Spearman's r = -0.29, P = 0.17; r = -0.20, P = 0.33); nor with four measures inversely related to sensation: volume at strong desire to void and maximum capacity on cystometry (r = -0.13, P = 0.53; r = -0.23, P = 0.28), and maximum voided volume and mean daytime voided volume on bladder diary (r = -0.29, P = 0.16; r = -0.16, P = 0.44). It was significantly associated with 24-hr urine output on bladder diary (Spearman's r = -0.55, P = 0.004).

CONCLUSIONS

Elevated NGF levels in human urothelium/suburothelium are not strongly associated with DO, detrusor contractility or increased bladder sensation. NGF levels are lower in subjects with higher 24-hr urine output. This observation is consistent with a role for NGF in an active process (trafficking) involved in bladder filling.