Dimethyl sulfoxide: does it change the functional properties of the bladder wall?

PURPOSE: Dimethyl sulfoxide (DMSO) is used in a 50% solution to treat interstitial cystitis. Symptomatic relief occurs in about two-thirds of cases. The mechanism of action and effects of DMSO on bladder tissue function are poorly understood. Therefore, the effect of DMSO on bladder muscle compliance and contractility was evaluated.

MATERIALS AND METHODS: Contractility and compliance were evaluated in rat bladder strips exposed to various concentrations of DMSO for 7 minutes, followed by 7 to 60-minute washout periods. The effect of DMSO at concentrations of 25%, 30%, 35%, 40% and 50% on electrical field stimulation induced contractions was assessed. Acetylcholine and high KCl (Sigma Chemical Co.) induced contractions were measured after exposure to 30% DMSO. Compliance was evaluated after exposure to 30% and 50% DMSO.

RESULTS: Exposure to 40% DMSO completely abolished electrical field stimulation contractions, while 30% DMSO decreased the electrical field stimulation contraction to 40% +/- 6% of the initial force but there was almost complete recovery within 30 minutes. Contractile force was unaltered by 25% DMSO. Acetylcholine and KCl stimulation after exposure to 30% DMSO produced contractile forces of 78% +/- 6% and 39% +/- 6% of pre-DMSO control contractions, respectively. Compliance decreased by 2.4 and 4.6-fold following 30% and 50% DMSO exposure, respectively.

CONCLUSIONS: DMSO completely and irreversibly abolishes contractions at a 40% concentration. Compliance is altered at even lower concentrations (30%). These findings bring into question the current practice of treating patients who have IC with 50% DMSO. Lower concentrations (25%) of DMSO may serve as a safe, effective analgesic and anti-inflammatory treatment for IC and other bladder pathologies.