The progression of doxorubicin-induced intestinal mucositis in rats

Chemotherapy-induced intestinal mucositis is a severe side effect contributing to reduced quality of life and premature death in cancer patients. Despite a high incidence, a thorough mechanistic understanding of its pathophysiology and effective supportive therapies are lacking. The main objective of this rat study was to determine how 10 mg/kg doxorubicin, a common chemotherapeutic, affected jejunal function and morphology over time (6, 24, 72, or 168 h). The secondary objective was to determine if the type of dosing administration (intraperitoneal or intravenous) affected the severity of mucositis or plasma exposure of the doxorubicin. Morphology, proliferation and apoptosis, and jejunal permeability of mannitol were examined using histology, immunohistochemistry, and single-pass intestinal perfusion, respectively. Villus height was reduced by 40% after 72 h, preceded at 24 h by a 75% decrease in proliferation and a sixfold increase in apoptosis. Villus height recovered completely after 168 h. Mucosal permeability of mannitol decreased after 6, 24, and 168 h. There were no differences in intestinal injury or plasma exposure after intraperitoneal or intravenous doxorubicin dosing. This study provides an insight into the progression of chemotherapy-induced intestinal mucositis and associated cellular mucosal processes. Knowledge from this in vivo rat model can facilitate development of preventive and supportive therapies for cancer patients.