High expression of type I inositol 1,4,5-trisphosphate receptor in the kidney of rats with hepatorenal syndrome

AIM: To detect the expression of type I inositol 1,4,5-trisphosphate receptor (IP(3)RI) in the kidney of rats with hepatorenal syndrome (HRS). METHODS: One hundred and twenty-five Sprague-Dawley rats were randomly divided into four groups to receive an intravenous injection of D-galactosamine (D-GalN) plus lipopolysaccharide (LPS; group G/L, n = 50), D-GalN alone (group G, n = 25), LPS alone (group L, n = 25), and normal saline (group NS, n = 25), respectively. At 3, 6, 9, 12, and 24 h after injection, blood, liver, and kidney samples were collected. Hematoxylin-eosin staining of liver tissue was performed to assess hepatocyte necrosis. Electron microscopy was used to observe ultrastructural changes in the kidney. Western blot analysis and real-time PCR were performed to detect the expression of IP(3)RI protein and mRNA in the kidney, respectively. RESULTS: Hepatocyte necrosis was aggravated gradually, which was most significant at 12 h after treatment with D-galactosamine/lipopolysaccharide, and was characterized by massive hepatocyte necrosis. At the same time, serum levels of biochemical indicators including liver and kidney function indexes were all significantly changed. The structure of the renal glomerulus and tubules was normal at all time points. Western blot analysis indicated that IP(3)RI protein expression began to rise at 3 h (P < 0.05) and peaked at 12 h (P < 0.01). Real-time PCR demonstrated that IP(3)RI mRNA expression began to rise at 3 h (P < 0.05) and peaked at 9 h (P < 0.01). CONCLUSION: IP(3)RI protein expression is increased in the kidney of HRS rats, and may be regulated at the transcriptional level.