Scratching behavior of ICR-derived glomerulonephritis (ICGN) mice.

The ICR-derived glomerulonephritis (ICGN) mouse, an inbred strain with a hereditary nephrotic syndrome, is considered a good animal model of human idiopathic nephrotic syndrome. ICGN mice show proteinuria at a young age, developing hypoalbuminemia, hyperlipidemia, anemia and edema later on. However, their behavior associated with pruritus due to renal dysfunction has not been sufficiently investigated. In the present study, we examined whether ICGN mice exhibit the scratching behavior reflecting pruritus. Mice aged 21 or 27 weeks were found to scratch persistently or intermittently, particularly those with scars. Furthermore, the scratching may have reflected a pruritus associated with renal dysfunction because it was inhibited by an opioid antagonist, naltrexone (3 mg/kg), effective against pruritus in hemodialysis patients. The results suggest that the ICGN mouse is a useful model with which to examine pruritus due to renal dysfunction.