Oxidative stress and enhanced paracellular permeability in the small intestine of methotrexate-treated rats
- 352 Downloads
We previously demonstrated the increase of reactive oxygen species (ROS) production and myeloperoxidase (MPO) activity in the small intestine of methotrexate (MTX)-treated rats. In the present study, we investigated the role of ROS modulating intestinal mucosal permeability in this damage.
MTX (20 mg/kg body weight) was administered to rats intravenously. N-Acetylcysteine (NAC; 80 mg/kg body wt), an antioxidant and a precursor of glutathione (GSH) was administered to rats intraperitoneally to investigate the contribution of ROS to the intestinal permeability enhancement. Intestinal permeability was evaluated by determining that of a poorly absorbable marker, fluorescein isothiocyanate-labeled dextran (FD-4; average molecular mass, 4.4 kDa) using the in vitro everted intestine technique. The occurrence of oxidative stress in the small intestine was assayed by measuring chemiluminescence and thiobarbituric acid reactive substances (TBARS) productions in mucosal homogenates of the small intestine.
The mucosal permeability of FD-4 significantly (p < 0.01) increased in MTX-treated rats compared with control rats, as demonstrated by a twofold increase of FD-4 permeation clearance. This suggests an increase in paracellular permeability. Interestingly, the ROS production was observed preceding the increase of paracellular permeability. Treatment with NAC prevented the MTX-induced ROS production and the increase of paracellular permeability.
NAC protected the small intestine of rats from MTX-induced change in paracellular permeability, suggesting that ROS played an important role in the enhanced paracellular permeability.
KeywordsMethotrexate Reactive oxygen species Intestinal permeability Chemiluminescence N-Acetylcysteine Glutathione
- 1.Thomas HJ (1987) Searching for magic bullet: early approaches to chemotherapy-antifolate, methotrexate. Cancer Res 47:5528–5536Google Scholar
- 2.Rosen G, Caparros B, Huvos AG, Kosloff C, Nirenberg A, Cacavio A, Marcove RC, Lane JM, Mehta B, Urban C (1982) Preoperative chemotherapy for osteogenic sarcoma: selection of postoperative adjuvant chemotherapy based on the response of the primary tumor to preoperative therapy. Cancer 49:1221–1230CrossRefPubMedGoogle Scholar
- 7.Khan SA, Wingard JR (2001) Infection and mucosal injury in cancer treatment. NCI Monogr 29:31–36Google Scholar
- 8.Keefe DM, Schubert MM, Elting LS, Sonis ST, Epstein JB, Raber-Durlacher JE, Migliorati CA, McGuire DB, Hutchins RD, Peterson DE (2007) Mucositis Study Section of the Multinational Association of Supportive Care in Cancer and the International Society for Oral Oncology updated clinical practice guidelines for the prevention and treatment of mucositis. Cancer 109:820–831CrossRefPubMedGoogle Scholar
- 9.Gibson RJ, Keefe DM, Clarke JM, Regester GO, Thompson FM, Goland GJ, Edwards BG, Cummins AG (2002) The effect of keratinocyte growth factor on tumour growth and small intestinal mucositis after chemotherapy in the rat with breast cancer. Cancer Chemother Pharmacol 50:53–58CrossRefPubMedGoogle Scholar
- 18.Sonis ST, Elting LS, Keefe D, Peterson DE, Schubert M, Hauer-Jensen M, Bekele BN, Raber-Durlacher J, Donnelly JP, Rubenstein EB (2004) Perspectives on cancer therapy-induced mucosal injury: pathogenesis, measurement, epidemiology, and consequences for patients. Cancer 100:1995–2025CrossRefPubMedGoogle Scholar
- 28.Edens HA, Levi BP, Jaye DL, Walsh S, Reaves TA, Turner JR, Nusrat A, Parkos CA (2002) Neutrophil transepithelial migration: evidence for sequential, contact-dependent signaling events and enhanced paracellular permeability independent of transjunctional migration. J Immunol 169:476–486PubMedGoogle Scholar