Study Of DFP On Protecting Against Heart Damage In Al-Exposed Rats

ObjectiveWith the development of industry and technology, the application of aluminum productions become more and more extensive in daily life. Although aluminum is non-essential elements of human body, the toxicity of aluminum should not be ignored. Studies have shown that aluminum can accumulate in human body and produce chronic toxicity. Furthermore, aluminum is widely distributed in the body, since the different exposure approach, dose and duration of aluminum in the body, the "target" organs are different, and the various organs of the organization will be injured. Heart is the organ pumping blood, heart disease, which caused by a variety of reasons, has aroused more and more widespread concerns. Therefore, the study of aluminum toxicity in the heart is particularly important. At present, eliminating mechanism of aluminum compound which exists in multiple exposure or can be transferred to other organs is undefined, clinical treatment tend to apply aluminum chelating agent to copy with the aluminum load. DFP (deferiprone,1,2-dimethyl-3-hydroxy-4-pyridone) is gradually known for the feature of effective and oral, initially it was applied as an iron chelator. Due to the similar nature of aluminum and iron elements, this study will consider DFP as an aluminum chelating agent in animal experiments, mainly from the DFP in the myocardium and serum aluminum in the row effect on other essential elements and myocardial cells to assess the protective effect of DFP on the heart toxicity.Methods 1 Animal treatments35 adult Male Wistar rats were obtained from the animals center of Shandong university, and they were 160～220g of weight upon arrival. The animals were acclimatized to the conditions of the animal room for about 1 week after arrival and were maintained on an adlibitum diet and tap water.The rats were divided into 5 groups randomly, the negative control group were given 0.9% saline lml/d, others were administered AICl3,5 times one week for 8 weeks. Then the groups except the negative control group were redivided into 4 groups, one of which received the 0.9%saline 1ml/day(positive control), the other three groups were administered at different doses of DFP(13.82,27.44, 54.88mg/kg/day). Two weeks later, the rats were sacrificed by decapitation and the samples were stored frozen in plastic flasks until analysis and the enzymes were determined immediately.2 Records of body weight and general situationWeighing body weight per day in order to determine the gavage measurement, rats were observed daily for appetite, mental state, actions, facial expressions and general condition of reaction speed. Weight growth was recorded once a week.3 Effects of DFP on aluminum chelation in rat's heart and serumMyocardial tissue of rats in each group were obtained, weight and dissolved with microwave instrument, then we determined Al content in myocardial tissue with graphite furnace atomic absorption spectrophotometry to observe the effect of DFP on aluminum.Serum of each group were obtained and dissolved with microwave digestion instrument. The levels of serum aluminum were observed by graphite furnace atomic absorption spectrophotometer method to analyze effect of DFP's exclusive aluminum.4 Effect of DFP on the serum myocardial enzymeRats in each group after the last gavage, fasting for 24h, were decapitated blood, the immediate collection of blood into the test tube,3500rpm×10min centrifugal, drawing the upper serum in the E-P tube, immediately AST, LDH and CK according to kit instructions determination. 5 Effects of DFP on antioxidant system in rats'myocardial tissueMyocardial, lung tissue and serum of rats in each group with a certain amount of normal saline were made into 10% tissue homogenate, the prepared tissue homogenate were used low-temperature centrifuge 3500rpm×10min, the prepared homogenization of the centrifugal clear liquid diluted with saline until determination.6 Effects of DFP on essential elements in myocardial, lung tissue and serumMyocardial, lung tissue and serum of rats in each group were obtained, weight and dissolved with microwave instrument. Then the various tissues of rats with copper, zinc, calcium, iron and magnesium were analyzed by flame atomic absorption spectrometry to exposed effects of DFP on essential element.7 Effects of DFP on rats'myocardial tissue damage morphologyRats heart tissue in each group hematoxylin-eosin staining (HE) staining for pathological observation, aluminum on rat heart cells in morphological changes and the role of DFP on their resume were observed.Results1 Records of body weight and the general situationRats in negative group were in good condition, well eating, thick and shiny coat, bright eyes, responsive, flexible movement, muscular flexibility; in the first 4 weeks, rats with narcotics showed matte coat, poor response and motility; A small number of rats in middle and high dose group showed skin redness, sweating and other phenomena, days later they were not unusual. Rats in each group were body weight growth, but no significant differences in the rate.2 Effects of DFP on aluminum chelation in ratsAfter administration of AICl3 for 8 weeks, significant accumulation of Al in heart tissue of Al-only was observed in comparison with negative control rats (P<0.01).The treatment of DFP administration significantly decreased the aluminum content in comparison to the positive control group.Aluminum exposure levels of serum aluminum content was higher than the negative control group (P<0.01), high-dose DFP group and decreased serum aluminum, but is still high compared with the negative control group (P<0.01).3 DFP on the serum myocardial enzyme of ratsIn the experiment, the level of LDH in serum of al-only group were significantly increased (P<0.01). While, after the treatment with DFP, the level in serum decreased singnificantly (P<0.01).CK is also a marker enzyme of heart injury, an increased level was found in positive group (P<0.01), the treatment with Lower dose DFP and median dose DFP were not significantly decreased, but the level of CK in higher dose of DFP decreased significantly (P<0.01).However, in this study, the results did not show any significantly difference in AST. So Al accumulation do not affect the level of AST in serum, and DFP is still no harm to the AST.4 Effects of DFP on antioxidant system in myocardial tissueThe tissue levels of MDA in Al-only animals increased siginificantly compared to the animals in the negative control group(P<0.01), and decreased significantly in animals with the median and high doses of DFP treatment comparing to the positive control animals (P<0.05, P<0.01).In the present study, the effects of DFP on antioxidant system which were damaged by aluminum were performed in.The level of GSH-Px in positive control group was found decreased obiviousely. However, the level of antioxidant enzyme GSH-Px increased significantly under three different doses. There was no change in overall T-SOD level was achieved between groups.5 Effects of DFP on other essential elementsThe comparison of the content of essential element in the myocardium between groups is illustrated. It shows that the decrease the content of iron, while, DFP was found effective in reducing heart Al, and recovering the Fe.Al-exposed rats serum Fe lower than the negative control group (P<0.05), in which high-dose group reduced DFP (P<0.05).However, it shows that there was no difference of Cu, Zn, Mg and Ca between groups.6 Effect of DFP on myocardial tissue damage morphologyNegative control group rats myocardial cells in morphologically normal cells, a clear cross striations, nucleus integrity, eosinophilic cytoplasm stained myofibrils arranged in neat rows, no obvious pathological changes in the normal stromal cells.Al-exposed group of myocardial cell injury, myocardial cells, gap increased, cell stripes and blurred staining increased eosinophilic cytoplasm, nucleus condensation, fragmentation. Myofibrils distorted, mesenchymal cells edema, a small number of muscle cells broken.In lower, medium and high-dose DFP group myocardial interstitial gradually reduced, the structure of rat myocardial cells gradually returned to normal.Conclusion1 The aluminum compounds can be accumulated in the myocardium, which can result in myocardial cell injury and affect the myocardial iron content..2 DFP promotes aluminum exclusion by chelating, thereby reduces aluminum load in serum and myocardium, so that makes the myocardial cell injury recover gradually.3 DFP improves biochemical indicators and myocardial pathological changes, such as myocardial enzymes, peroxides enzymes caused by aluminum, by means of promoting the exclusion of aluminum in myocardial tissue of rats carrying aluminum,4 DFP has no effect on the content of essential elements, Zn, Fe, Ca, Mg, and Cu, of the heart organs of rat dyeing of aluminum, but has some exclusive effect on the element Fe in serum to a certain degree, so in the DFP treatment of aluminum intoxication, the supplement of iron should be attention.