Cystometric Evidence that Capsaicin-Sensitive Nerves Modulate the Afferent Branch of Micturition Reflex in Humans

Abstract

Intravesical instillation of capsaicin (0.1 to 10 microM) in six patients (five with hypersensitive disorders of the lower urinary tract, one with benign prostatic hyperplasia) produced a concentration-related reduction of the first desire to void, bladder capacity and pressure threshold for micturition. At a threshold concentration of one microM, capsaicin also produced a warm to burning sensation referred to the suprapubic area during the collecting phase and to the urethra during micturition. All the patients with hypersensitive disorders of the lower urinary tract reported disappearance or marked attenuation of their symptoms for a few days after capsaicin application. In three other patients with hypersensitive disorders of the lower urinary tract, intravesical instillation of capsaicin's vehicle (0.1% ethanol in saline) did not produce significant cystometric changes nor modify the symptomatology. These observations provide the first indication that capsaicin-sensitive structures (nerves?) may be present in the human urinary bladder as they have been shown to occur in various other species.

Chillies: from antiquity to urology

“…perform cystometrography or on the outer surface of the rat bladder was shown to stimulate reflex micturition In May 1990, the first attempts to treat detrusor hyper-reflexia with intravesical capsaicin were made at [28,29]. Furthermore, the intravesical instillation of xylene, a C-fibre irritant, has been shown to induce our institution using the same doses as reported by Maggi et al [33]. However, the results were disappointing visceral pain in rats via the activation of capsaicinsensitive aCerent fibres [30].…”

“…Capsaicin was therefore tried in reported by Maggi et al in 1989 [33]. Administering capsaicin (0.1-10 mmol/L) to six patients (five with patients with intractable detrusor hyper-reflexia unresponsive to anticholinergics, to determine if a similar hypersensitive bladders and one with BPH) produced a reduction in the first desire to void, the bladder capacity C-aCerent-mediated vesical reflex became active in spinal cord diseases like multiple sclerosis.…”

“…Patients initially deteriorated symptomatically for a period of 2 days to 2 weeks, but this was the capsaicin vehicle (0.1% ethanol in saline) with no significant symptomatic or cystometric changes [33].…”

“…The benefit lasted for 3-4 months, when the instillations were repeated In 1993, Barbanti et al [34] reported the relief of pain using intravesical capsaicin in the same doses as had using 2 mmol/L of capsaicin. Over a 5-year period, the beneficial eCect of these repeated instillations was susbeen used by Maggi et al [33] in patients with hypersensitive bladder disorders. However, since then a randomized, tained in those who responded to the initial instillations.…”

Advances in the pharmacological control of the bladder

“…Cystometric evidence that capsaicin-sensitive nerves may modulate the afferent branch of the micturition reflex in humans was originally presented by Maggi et al (1989), who instilled capsaicin (0-1-1 0 ,UM) intravesically in five patients with hypersensitivity disorders.…”