The Correlational Study Of L-carnitine And Renal Anemia

Research BackgroundIt is well known that incidence of chronic renal function insufficiency is increasingly higher and they will develop to chronic renal failure (CRF) at the end, which is end stage of renal disease (ESRD). A cross-sectional survey’s results were published in the Lancet in 2012 about the incidence of CRF in China. Eventually there are 47,204 cases surveyed, including glomerular filtration rate< 60 ml/min (1.7%), albuminuria (9.4%), etc. The prevalence of chronic kidney disease was 10.8%. Based on it, it is speculated that there is about 119,500,000 patients with chronic kidney disease in Chinese. Large digital indicates that each kidney worker has a long way to go.CRF is the common end result of chronic kidney disease and a variety of chronic diseases. Hemodialysis is one of the common alternative treatment of ESRD. As the state’s overall strength increased and the perfect social security system, there are more and more patients with maintenance hemodialysis (MHD). In recent years, the annual growth rate of dialysis is around 15% in China, which is far more than developed countries (about 5% is its annual rate of in the number of dialysis patients). Because a lot of patients in ESRD have not been treated in our country, so the increasing speed will be stayed for quite a long time. And according to the ministry of public health in recent data: the number of registered hemodialysis in China has reached about 260,000 (30,000 in 2001) by 2011, and about 20,000 people of peritoneal dialysis (only about 5000 people in 2011). The compound annual growth rate in hemodialysis and peritoneal dialysis are 23.8% and15.1% respectively in ten years. For such a large team of MHD patients, how to improve the quality of survival, prolong the survival period to the largest limite, increase the proportion of young patients return to society? These solving problems are hot spots for blood purification professional research.Renal anemia is one of the common complications of CRF. It affects not only the patient’s life quality and survival time, which could also be caused by secondary related diseases of the cardiovascular system, etc. Therefore prevention and amend of renal anemia has become the symbol of the quality of hemodialysis and is also necessary to improve the quality of hemodialysis center link. Renal anemia occurred mainly because of erythropoietin (EPO) secretion decline, poor nutrition (particularly iron deficiency), and shorten the life of erythrocytes, and excessive apoptosis cause shortened lifespan and decrease in the number. So for erythrocytes of patients in uremia, whether there is excessive apoptosis and ultimately affects the occurrence and development of renal anemia? It has been confirmed that cause there are more erythrocytes to apoptosis in uremia environment. In clinic, it is effectively corrected by the invention of the recombinant human erythropoietin and the wide application of intravenous iron, which was improved by blood transfusion at one time and reducing the way to spreading disease through blood transfusion. But there is still some refractory anemia, which is difficult to correct the hemoglobin rise to normal levels after conventional treatment. For these patients, what steps can we take?All the time, erythrocytes from original in bone marrow to mature, then distribute in circulation pool, finally consumed by the spleen after aging of the whole process, inevitably affected by various stimulus from internal environment. And ESRD has created a special body within the environment. The body produces metabolic product is associated with kidney failure after normal excretion, according to its different sources mainly includes the following three categories:① the body of toxins, produced by the main body, mainly through the kidneys and kidney cannot discharge, often the blood purification method is unable to remove all kinds of macromolecule toxins, protein toxin, etc;② replacement therapy for a long time can activate oxidative stress, which are reaction product of oxidative stress, etc.;③long-term replacement therapy after the activation of inflammatory cytokines produced by microinflammation, etc. These called "uremic toxins" are negative factors for the erythrocytes in the process of the entire life, which maybe produce negative effects for the survival of the erythrocytes. Erythrocytes have the normal life of about 120 days, but, erythrocytes in ESRD significantly shorten the service life, reduced from 128±28 days to 89±28 days. Vos FE etc. studied the patients in maintenance hemodialysis and peritoneal dialysis, the median survival time of erythrocytes of both has no statistical difference, which is about 20% less than normal survival. The result indicated abnormal environment in uremia directly make RBC life to decline to almost a third, and shorten the life of erythrocytes will increase the degree of the occurrence of renal anemia. Erythrocyte quantity is negatively correlated with the demand for exogenous EPO , the more the number of erythrocytes, the less amount of EPO supplementary. Of course, body weight, serum creatinine, albumin, urea nitrogen, total cholesterol influence factors of exogenous EPO dose. Bi SH etc. investigated there is a negative correlation between hemoglobin and phosphatidylserine (PS) expression on erythrocytes. Their tests prompted PS excessive expression is a risk factor for renal anemia, which promotes the occurrence of anemia.Sinistral carnitine (L-carnitine, LC) usually appears as a cofactor in fat mobilization, mainly through transporting long-chain fatty acyl coenzyme A from outside activating site of mitochondria to the oxidation of location in the mitochondrial matrix for beta oxidation. So far, it have been confirmed in part that LC has positive significance in improving renal anemia. And some literatures in recent years showed that maintenance hemodialysis patients could reduce the dosage of EPO and correct anemia more effectively after LC supplement. For refractory anemia, it also has certain corrective effect. But for the maintenance hemodialysis patients within only one year, this utility is not obvious after added LC. Therefore, we speculated that the LC in the human body is mainly by maintaining moderate concentration in the blood and has a positive role on the decline and fall of erythrocytes. Since population entering blood dialysis can temporarily keep quite concentration and normal, lack is not very serious which can explain why the method isn’t effective in dialysis patients which a year.LC is benefit for renal anemia. The possible mechanisms involved include the following aspects. LC can improve the sensitivity of erythrocytes of EPO, thus promotes the generation of erythrocytes; LC increase the red cell membrane fluidity and permeability,improve the resistance of the external environment, directly to extend the lifetime of erythrocytes; LC inhibit apoptosis of Jecet cells, the trial shows that it can inhibit apoptosis pathways related Fas. Arduini A the experiment confirmed in 25℃ environment, LC can reduce the hemolysis of erythrocytes, improve the survival of suspended erythrocytes. These conclusions indicate LC may be have inhibitory effect on the decline of erythrocytes.It has been validated by test that LC can prolong the life of erythrocytes. Through 51Cr markers, Arduini A found that the storage of erythrocytes can also produce acetoxylation carney, which is basic energy consumption of storaged erythrocytes and is associated with fatty acid oxidation. Erythrocytes in the storage of the 42nd, LC associated with reducing hemolysis of erythrocytes and ATP levels in red cells increasing, and have obvious difference between the control group and the test group. Sweeney JD etc. found that adding LC to storage liquid more conducive to the survival of erythrocytes and platelets. He observed in storage liquid adding LC to the platelets, platelet on morphology, liquid PH, lactate, the range of deformation is saline liquid storage, has obvious effectiveness, and has some certain relevance. So he speculated that LC extended the survival of the platelets by reducing the glycolysis to maintain a good PH level. Although the authors did not further discussed from the molecular mechanism, but these experiments still prompted LC can extend the life of the erythrocytes.In recent years, it also found that the LC has powerful antioxidant effect which plays a positive role in a variety of kidney diseases. For example, in renal ischemia-reperfusion injury, the renal toxicity of drug damage (including cisplatin and cyclophosphamide; effective antibiotics gentamicin; hypertonic pharmaceutical glycerine, doxorubicin, etc.), by such, LC have been proved to have the exact kidney protection.But what exactly mechanisms participate in LC influence on erythrocyte decay? There has not report about the LC of erythrocytes in uremia decay and related mechanism in China and abroad. We speculate that the LC can effectively restrain uremia patients by antioxidant effect, so as to prolong the life of RBC, improve the renal anemia. This may be one of the mechinisms that maintenance hemodialysis patients reduce the dosage of EPO after using LC.This study will test the hypothesis. In vitro, we use human erythrocyte as a cell model, apply different uremic serum concentrations in culture to stimulate the healthy erythrocytes, the healthy erythrocytes in patients with uremic serum spurred by the expression of PS, PS expression changes after LC intervention. And at the same time, reactive oxygen species (ROS) and glutathione (GSH) of erythrocytes were determined. Through the research of ROS and GSH of erythrocytes changed,; we observed whether LC inhibit eryptosis in uremia and whether the mechanism is related to the oxidation.THE FIRST PARTL-CARNITINE INHIBITES ERYPTOSIS IN UREMIC SERUM AND THE RELATED MECHANISMPurposeExplore the protective effects of L-carnitine in uremic serum of erythrocytes and the related mechanisms.Methods1% of healthy erythrocytes suspension was incubated respectively in different cultures in vitro. Three groups included:control group (group C), uremic serum groups (group U) and L-carnitine group (group L). Erythrocytes were collected at 24 h,48 h of incubation, respectively. Flow cytometry instrument were used to detect eryptosis (PS) and erythrocytes reactive oxygen species (ROS), and enzyme-linked immunoassay were used to detect of erythrocyte glutathione (GSH) content.Results1. With the extension of incubation time in vitro, eryptosis increase. In each group, eryptosis is higher at 48 h compared with at 24 h. Eryptosis is higher in group U compared with in group C (24 h:6.51 ± 0.71 vs.3.43±0.37, P< 0.01; 48 h:8.55 ± 0.76 vs.4.21 ± 0.44, P< 0.01), while lower in the L group compared with U group (24 h:5.80 ±0.69, P< 0.05; 48 h:P< 0.05; 7.87±0.76, P< 0.05).2. With the extension of incubation time in vitro, ROS generation of erythrocytes increased and GSH decreased. In each group, ROS generation is higher and GSH generation is lower at 48 h compared with at 24 h. ROS generation is higher (24 h:33.12±1.61 vs.14.83±2.22, P< 0.01; 48 h:42.06±1.81 vs.20.94±1.78, P< 0.01), GSH generation is lower (24 h:25.66±0.32 vs.31.27±0.38, P< 0.01; 48 h:8.53 ± 0.59 vs.17.29±0.54, P<0.01.) ROS generation is lower (24 h:26.29 ±1.69, P< 0.01; 48 h:36.21±2.00, P< 0.01) and GSH generation is higher (24 h:27.54±0.60; P< 0.01; 48 h:15.18±0.42; P< 0.01) in group L compared with group U.3. Correlation analysis is made by each index. Eryptosis is positively correlated with ROS and negatively correlated with GSH, ROS is negatively correlated with GSH.Conclusion1. The uremic serum induced normal erythrocytes to accelerate eryptosis which is dependent on time.2. L-carnitine inhibits eryptosis induced by uremic serum and the mechanism may be related to the antioxidant effect.THE SECOND PARTL-carnitine’s influence on renal anemia by intravenous ironPurposeIt is of great significance of for renal anemia. But at the same time, oxidative stress is enhanced. L-carnitine is supplied with intravenous iron at the same time and observed the change of oxidative stress.MethodsThe Prospective, randomized, controlled study was adopted.20 cases of MHD group patients were selected and divided into control group (intravenous iron) and experimental group (intravenous iron L-carnitine group). There were 10 cases in each group.100 mg of iron will be diluted to 100 ml saline solution and were intravenous dripped at the third hour in each process of hemodialysis. Iron sucrose Injection was used 3 times a week in the control group. At the same time, L-carnitine was injected 1.0 g after the hemodialysis intravenous in experimental group. The tota amount of iron in both groups was 1000 mg. All cases were combined use of EPO treatment. Oxidative stress indicators were observed and compared after treatment between the two groups.Results1. There were no difference in Hb and indexes of oxidative stress between control group and experimental group before the treatment.2. After treatment, Hb was increased (90.34±12.87 vs.84.32 ± 10.25, P<0.01) and (92.56±15.67 vs.85.41±12.63, P<0.01) in the control group and experimental group, respectively.3. After treatment, MDA and AOPP were higher in both groups. There was statistically difference between the two groups. SOD, CAT, TAOC, GSH-Px were lower in both groups. There was statistically difference between the two groups.Conclusion1. Intravenous iron causes oxidative stress in the patients in chronic renal failure.2. L-carnitine restrains oxidative stress caused by iv. iron in part.