ABSTRACT
Objective To investigate the effect of hyperuricemia (HUA) on nuclear factor-κB (NF-κB) in myocardial tissue,Mn superoxide dismutases (Mn-SOD) activity in mitochondria,cardiac function of rats with HUA.Methods Sixty SD male rats,including 30 young rats and 30 aged rats,were randomly divided into four groups:the young control group,the young HUA group,the aged control group and the aged HUA group.Fifteen rats were in each group.The HUA rat models were set up by lavage method with yeast extract and ethambutol.Left ventricular systolic pressure (LVSP),left ventricular end-diastolic pressure (LVEDP) and left ventricular pressure at the end of the rising and falling maximum velocity (+dp/dtmax) were determined by intubation in the left ventricle with cardiac catheter.Mn-SOD activity in the mitochondria of rat myocardial tissue was detected by chemical colorimetry.The expressions of NF-κB in rats myocardial tissue were measured by immunohistochemistry (IHC) and reverse transcription polymerase chain reaction (RT-PCR).Differences between groups were analyzed with One way analysis of variance,Student-Newman-Keuls q test was used to compare the mean of multiple samples.Results Hyperuricemia had no significant effect on the cardiac function of HUA groups (P＞0.05).But the gene and protein expression of NF-κB in myocardial tissue and Mn-SOD activity of mitochondria were impacted by HUA.Both the gene and protein expression of NF-κB and the activity of Mn-SOD in HUA groups were increased (F=85.428 4,120.683 0 and 398.228 3,P＜0.01).Furthermore,the increase of gene and protein expression of NF-κB and the Mn-SOD activity in rats myocardial tissue of young HUA group were higher than those in aged HUA group (q=6.818 6,10.693 6 and 18.877 9,P＜0.05).Conclusion Hyperuricemia may cause inflammation and increase oxygen free radicals in myocardial tissue on one hand,and it may reduce inflammation and protect the myocardial tissue by increasing the activity of Mn-SOD in myocardial mitochondria of HUA rats,and removing the oxygen free radicals on the other hand.The response to uric acid in young HUA group is stronger than that in the aged HUA group.