The possibility of LA-induced expression of ROS was assessed. This could lead to an increased cell death rate. Production CP-868596 clinical trial of ROS after a short incubation (5 h) with lidocaine or bupivacaine was enhanced

with increasing concentrations from 0·3 mg/ml and 0·6 mg/ml to 1·3 mg/ml (Fig. 5a). For ropivacaine, no ROS production was observed. After incubation with lidocaine and bupivacaine a decrease in viability was measured, while viability of fibroblasts was not impaired in the presence of ropivacaine (Fig. 5b). Viability of fibroblasts correlated negatively with production of ROS (Fig. 6a and b). The highest correlation was observed in the bupivacaine group (Pearson’s correlation −0·74) (Table 1), while the correlation value for lidocaine was −0·53. As no ROS were generated in the presence of ropivacaine, the correlation coefficient was not relevant for this

LA. Caspase-3 activity did not increase upon short-term learn more incubation with any of the three LA tested (data not shown). This in vitro study shows a cytotoxic effect of lidocaine, bupivacaine and ropivacaine on fibroblasts. In group 1, with exposure to local anaesthetics for 2 days followed by incubation with normal medium, cells were only slightly impaired upon stimulation with lidocaine and ropivacaine. However, bupivacaine had a significant concentration-dependent impact. In group 2, where fibroblasts were exposed permanently to LA, cells were impaired time- and concentration-dependently with all LA. The most negative effect was observed after exposure to bupivacaine. We assume that single injections do not

impair the tissue. Compared to previous investigations, the present study is original because: (i) three different local anaesthetics were tested, (ii) experiments were performed Verteporfin in vivo in cell culture of human fibroblasts, (iii) different concentrations of LA were evaluated, (iv) different incubation periods were assessed and (v) a possible mechanism of cytotoxicity was tested. This broad and carefully designed approach allows detailed conclusions to be drawn concerning wound healing in the presence of LA. Previous experiments have demonstrated a possible impairment of the proliferation rate of cells such as type II pneumocytes or endothelial cells [21,22]. These data reflected the impact of local anaesthetics in very low concentrations, as found in the respiratory or vascular compartments. Our study, however, focused upon concentrations observed after injection into a wound area. A retrospective analysis of shoulder arthroscopy with intra-articular bolus injection of 0·25% bupivacaine with adrenaline described chondrolysis as a devastating complication [23].