The Effects of Local Anesthetics on the Human Bladder Contractility: Organ Bath Study

Paick, Sung Hyun; Lim, Dae Jung; Lee, Eunsik; Lee, Sang Eun; Choi, Hwang; Oh, Seung June

Abstract

PURPOSE: We investigated the in vitro effects of local anesthetics on the contractility of the human bladder.
MATERIALS AND METHODS
Using human bladder strips obtained from 20 patients undergoing cystectomy, we investigated the effects of tetracaine, bupivacaine, lidocaine, and ropivacaine on the basal spontaneous contractions and contractions induced by various stimuli: KCl, carbachol (CCh), and electrical field stimulation (EFS). The effect of local anesthetic agents on the Ca2+ -independent sustained tonic contraction (SuTC) was also investigated.
RESULTS
Spontaneous contraction was not observed in 181 out of 187 bladder strips. Local anesthetics inhibited nerve-mediated contractions (EFS, 0.8msec) in a concentration-dependent manner and also inhibited non-nerve mediated contractions induced by KCl, long pulse EFS (direct muscle stimulation, 100msec), and CCh. The rank order of inhibitory potency on nerve-mediated contractions and CCh-induced contractions was ropivacaine, tetracaine, bupivacaine, and lidocaine, while the rank order on KCl-induced contractions was ropivacaine, tetracaine, lidocaine, and bupivacaine, both in decreasing order. Higher concentrations of local anesthetics were needed to inhibit the non-nerve-mediated bladder contraction than the nerve-mediated contraction. SuTC was also suppressed by all local anesthetics in a concentration dependent manner.
CONCLUSIONS
Our study demonstrates that local anesthetics have inhibitory effects on the contraction of human bladder that is induced by various stimuli. These effects suggest that local anesthetics may be useful as diagnostic and therapeutic agents for bladder dysfunction.