Central actions of bethanechol on the urinary bladder in dogs

Bethanechol has been used to promote bladder emptying although the clinical efficacy of bethanechol remains uncertain. Both laboratory and clinical observations suggest that the pharmacologic actions of bethanechol are dependent to some extent on intact reflex mechanisms of the bladder. The objective of this study was to determine the effects of central nervous system administration of bethanechol on reflex detrusor contractions. Twelve isolated cross perfusion studies of the central nervous system in dogs were done to determine the cystometric response to central bethanechol administration. Central bethanechol resulted in reflex bladder contractions, decreased cystometric volume, increased maximum intravesical pressure, and increased periurethral EMG activity. This study demonstrated a central nervous system site of pharmacologic activity of bethanechol.