[Effect of crotonaldehyde long-term exposure induced kidney inflammatory and oxidative injury in male rats].

Objective: To observe the effect of crotonaldehyde long-term exposure on kidney injury in male rats, and to explore the specific mechanism of toxic action. Methods: 32 specific pathogen free healthy adult male wistar rats were randomly divided into 4 groups with 8 rats in each group: high-, moderate-, low-dose groups and a control group. Rats were treated with 8.5, 4.5, 2.5 and 0.0 mg/kg body weight crotonaldehyde by gavage, once a day for consecutive 128 days. After the last treatment, they were sacrificed and separated bilateral kidney. Kidney organ coefficients were calculated and the histopathology changes in kidney were observed by HE staining. The activities of malondialdehyde (MDA) , superoxide dismutase (SOD) , glutathion peroxidase (GSH-Px) and the levels of malaondialdehyde uric acid (UA) , urea nitrogen (BUN) , creatinine (CR) in serum were determined in the same time. Moreover, the levels of interleukin (IL) -6, 8, interferon (IFN) -γ and tumor necrosis factor (TNF) -α in kidney were determined by enzyme linked immunosorbent assay. Results: Bilateral kidneys in the 8.5 mg/kg group were reduced in size and dark in color. Under the microscope, the major pathology changes of kidneys could be summarized as summarized as protein cast renal tubule, inflammatory cells and lymphocytes infiltration among kidney cortex. Compared with the control group, the weight gain of rats in 8.5 mg/kg group were smaller, and the weight and organ coefficient of kidney in each groups were significant decreased ( P <0.05) . With the increasing dosage of crotonaldehyde, the serum BUN and UA levels in 8.5, 4.5 mg/kg groups, CR level in 8.5 mg/kg group were significant increased ( P <0.05) .Compared with the control group, the serum MDA level in 8.5 mg/kg group was significant increased ( P <0.05) . However, serum SOD activity in 8.5 mg/kg group and GSH-PX activity in 8.5, 4.5 mg/kg groups was significant decreased ( P <0.05) . With the increasing dosage of crotonaldehyde, there are upward trend in the kidney IL-6, IL-8, TNF-α, IFN-γ, β-2 microglobulin levels. Compared with the control group, IL-6, TNF-α, IFN-γ, β-2microglobulin levels in 8.5, 4.5 mg/kg groups and IL-8 level in 8.5 mg/kg group in kidney were significant increased ( P <0.05) . Conclusion: Crotonaldehyde could develop the inflammatory factors levels and change the oxidation balance condition in the kidney of male rats, causing the inflammatory and oxidative injures of renal tissues.