Botulinum-A toxin injections into the detrusor muscle decrease nerve growth factor bladder tissue levels in patients with neurogenic detrusor overactivity.
OBJECTIVE
We investigated the effects of BTX-A on visceral afferent nerve transmission by measuring bladder tissue NGF levels in patients with neurogenic detrusor overactivity before and after intravesical treatment with BTX-A. We also compared the bladder tissue NGF content with clinical and urodynamic data.


METHODS
A total of 23 patients underwent clinical evaluation and urodynamics with detection of the UDC threshold, maximum pressure and maximum cystometric capacity before, and at the 1 and 3-month followups. Endoscopic bladder wall biopsies were also obtained at the same time points. NGF levels were measured in tissue homogenate by enzyme-linked immunosorbent assay (Promega, Madison, Wisconsin).


RESULTS
At 1 and 3 months mean catheterization and incontinent episodes were significantly decreased (p <0.05 and <0.001, respectively). On urodynamics we detected a significant increase in the UDC threshold and maximum cystometric capacity, and a significant decrease in UDC maximum pressure at the 1 and 3-month follow-ups compared to baseline (each p <0.001). At the same time points we detected a significant decrease in NGF bladder tissue content (each p <0.02).


CONCLUSIONS
BTX-A intravesical treatment induces a state of NGF deprivation in bladder tissue that persists at least up to 3 months. As caused by BTX-A, the decrease in acetylcholine release at the presynaptic level may induce a decrease in detrusor contractility and in NGF production by the detrusor muscle. Alternatively BTX-A can decrease the bladder level of neurotransmitters that normally modulate NGF production and release.
Giannantoni
Antonella
A
Department of Urology, University of Perugia, Perugia, Italy. agianton@tin.it
Di Stasi
Savino M
SM
Nardicchi
Vincenza
V
Zucchi
Alessandro
A
Macchioni
Lara
L
Bini
Vittorio
V
Goracci
Gianfrancesco
G
Porena
Massimo
M
D000283:Administration, Intravesical; D000328:Adult; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage* / Q000494:pharmacology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D020932:Nerve Growth Factor / Q000032:analysis* / Q000096:biosynthesis*; D009465:Neuromuscular Agents / Q000008:administration & dosage* / Q000494:pharmacology; D001743:Urinary Bladder / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism*; D001750:Urinary Bladder, Neurogenic / Q000188:drug therapy* / Q000378:metabolism*
D009465:Neuromuscular Agents; D020932:Nerve Growth Factor; D019274:Botulinum Toxins, Type A