Preliminary study of ethylene glycol-induced alanine-glyoxylate aminotransferase 2 expression in rat kidney

Ethylene glycol (EG), a frequently used lithogenic agent, causes calcium oxalate crystal deposits in the renal cortex and causes death if over-dosage. In this study, we compared the protein expression pattern of rat renal lithiasis induced by EG with that of normal renal tissues using two-dimensional electrophoresis (2-DE). Sixteen male Sprague-Dawley rats were divided into 2 groups. In control group (n = 8), rats were fed with normal drinking water; in EG group (n = 8), rats were fed with 0.75% EG in drinking water. After 4 weeks, rats fed with EG had calcium oxalate deposited in renal cortex. The renal cortex proteins were extracted and isolated by 2-DE. Comparative analysis of the respective spot patterns on 2-DE were identified by matrix-assisted laser desorption ionization-time of flight-mass spectrometry technique. Among them, overexpression of alanine-glyoxylate aminotransferase 2 (AGT2) in rat renal lithiasis was confirmed by realtime polymerase chain reaction analysis. The data show that overexpression of AGT2 was involved in EG-induced rat renal lithiasis. Since AGT2 is a key enzyme in glyoxylate detoxification, our preliminary results suggest AGT2 may play some important roles in response to EG-induced stone formation.