Morphology of glomerular hematuria is reproduced in vitro by carbonyl stress.

ABSTRACT

BACKGROUND: In glomerulonephritides, dysmorphic red blood cells (RBCs) with membrane blebs can be found in the urine; this is referred to as glomerular hematuria. Glomerulonephritides are characterized by increased carbonyl stress and elevated methylglyoxal (MGO) levels. MGO causes oxidative stress and intracellular calcium accumulation. In the present study, we investigated whether the effect of MGO-induced calcium accumulation in RBCs develops through increased oxidative stress. Furthermore, we studied whether MGO can lead to RBC membrane blebbing. METHODS: RBC suspensions from healthy volunteers were incubated with different concentrations of MGO at 37 degrees C. We measured oxidative stress and intracellular calcium level using fluorescent indicators. We determined the frequency of dysmorphic RBCs, and also performed scanning electron microscopy. RESULTS: MGO increased oxidative stress and caused accumulation of calcium in isolated RBCs. These effects could be prevented using antioxidants. In the presence of MGO, RBC membrane blebbing developed. CONCLUSION: According to our findings, MGO causes calcium accumulation through oxidative stress. Carbonyl and oxidative stress may play an important role in the formation of dysmorphic RBCs in glomerular hematuria.