Protective Effect of Hyaluronic Acid on Cyclophosphamide-Induced Cystitis in Rats

Abstract

Purpose: We investigated the effect and duration of hyaluronic acid (HA) on the bladder of rats with cyclophosphamide (CYP)-induced cystitis. Materials and Methods: CYP (250 mg/kg) was injected intraperitoneally in female Sprague-Dawley rats to induce cystitis. HA (0.5%) was instilled intravesically. First, the rats were separated into 2 groups for urodynamic study (CYP group, CYP+HA group), and we assessed the inter-contraction interval, maximal voiding pressure (MVP), and pressure threshold of the 2 groups. Second, the rats were separated into 3 groups to assess the duration of effect of HA (CYP group; HA-1 group: HA was instilled 1 day before injection of CYP; HA-3 group: HA was instilled 3 days before injection of CYP), and we assessed the voiding interval for 7 days after confining the rats in metabolic cages. Results: The inter-contraction interval of the CYP+HA group (236.018.3 min) was significantly longer than that of the CYP group (178.013.4 min; p 1.2 vs. 34.02.4 cmH2O, respectively; p=0.56). The pressure threshold of the CYP+HA group (9.90.5 cmH2O) was significantly longer than that of the CYP group (13.20.7 cmH2O; p=0.002). The voiding interval decreased in each of the 3 groups according to the time after cystitis had been induced. The voiding interval was maximally decreased on the second day and returned to the pre-CYP injection level on the fifth day in each group. There was a significant difference in voiding interval among the 3 groups on the second day (p0.05). Conclusions: HA has an effect of increasing the voiding interval in rats with CYP-induced cystitis, and the duration of effect is concluded to be 5 days.