p.) had bladders removed 4 h after treatment. Changes in urinary bladder wet weight/body … CY-Induced Hepatic and Systemic Toxicity. In addition to changes in bladder, we also measured systemic markers of general toxicity to assess whether GSTP-induced protection was restricted to the bladder. Treatment with CY (200 mg/kg, i.p.) significantly increased selleck chemicals Olaparib plasma total and low-density lipoprotein cholesterol. CY increased plasma aspartate aminotransferase and decreased plasma total protein in GSTP-null mice but not in WT mice (Table 4). Because these data indicated a hepatic locus of CY toxicity, we measured hepatic metabolism of CY. Our results show that acrolein formation from CY was similar in hepatic microsomes isolated from WT and GSTP-null mice (WT, 2.28 �� 0.15; GSTP-null, 2.10 �� 0.

06 nmol product formed/min/mg protein). These observations show that there was no difference in the microsomal activation of CY in the livers of CY-treated WT and GSTP-null mice. Likewise, we did not observe any obvious alterations in hepatic histology in H&E-, MPO+-, acidified toluidine blue-, and apoptosis-stained sections in CY-treated WT and GSTP-null mice (4 and 24 h post-CY), indicating no obvious hepatic damage. No significant differences in the relative weight of major organs were noted (Table 5). Mesna pretreatment significantly decreased the gain in stomach weight gain in treated GSTP-null mice (+138 �� 12% of control; n = 5) to a greater degree than in WT mice (+214 �� 15% of control; n = 5). Overall, these observations suggest that deletion of GSTP neither exaggerated systemic CY toxicity nor affected hepatic activation of the prodrug.

Table 4 Blood and plasma parameters in WT and GSTP-null mice Table 5 Body weight (BWT) and organ wet weight/BWT ratios in WT and GSTP-null mice Discussion The major finding of this study is that GSTP protects against CY-induced bladder toxicity, in part by promoting bladder-specific metabolism and detoxification of acrolein, the major urotoxic CY metabolite. This conclusion is based on the observations that CY-treated GSTP-null mice displayed greater bladder injury, disintegration of lamina propria, and additional sloughing (exfoliation) of the urothelium than in the WT mice. The GSTP-null mice also displayed a greater increase in vascular permeability (edema, albumin leakage) and inflammation.

These changes were accompanied by a greater accumulation of protein-acrolein adducts and JNK/c-Jun hyperactivation in the bladder of CY-treated GSTP-null mice. Nevertheless, pretreatment with mesna prevented increased bladder injury and inflammation in CY-treated GSTP-null mice to the same extent as in WT mice, indicating that these changes in GSTP-null mice were caused by exaggerated electrophilic stress and not the result of nonspecific genetic changes caused by constitutive deletion Brefeldin_A of the GSTP gene.