Case Report: Carnitine Palmitoyl Transferase II (CPT II) Deficiency

Carnitine Palmitoyl Transferase II (CPTII) is a very important enzyme that helps with the oxidation of long-chain fatty acid to produce energy. Deficiency in CPTII will lead to energy deficiency in the case of fasting and the accumulation of the long chain fatty in the body. There are three types of CPT II deficiency, the myopathic form, the severe infantile hepatocardiomuscular form and the lethal neonatal form. They are all inherited as an autosomal recessive. Diagnosis of the CPTII are 1) tandem mass spectrometry (MS/MS) in adult form and 2) CPTII polymorphism (F352C), which is linked to reducing the activity of CPTII in infantile form [1]. Glucose is the primary management and medium-chain fatty acid is an alternative due to the bypass of the CPTII enzyme in the pathway. For the prevention of CPTII deficiency are to avoid long chain fatty acid (C12-fatty acid), fasting, prolonged exercise, known triggers, and certain medications such as anti-epileptics and general anesthesia. During the rhabdomyolysis and myoglobinuria attack, it is very important to maintain hydration to avoid acute renal failure. If, however, renal failure occurs, dialysis is recommended. We present a case of a 27-year-old African American woman with the significant past medical history of CPT II deficiency leading to recurrent rhabdomyolysis and myoglobinuria. Together with all the research studies from diagnosis to treatment of CPTII deficiency will help in clinical management of patients. And this case report will add to the existing case reports of patients who have CPTII deficiency in terms of how we diagnose, how we treat, and how we prevent symptoms from re-occurring.

Mitochondrial carnitine palmitoyltransferase-Ⅱ dysfunction: A possible novel mechanism for nonalcoholic fatty liver disease in hepatocarcinogenesis

Nonalcoholic fatty liver disease(NAFLD)or metabolic-associated fatty liver disease has been characterized by the lipid accumulation with injury of hepatocytes and has become one of the most common chronic liver diseases in the world.The complex mechanisms of NAFLD formation are still under identification.Carnitine palmitoyltransferase-Ⅱ(CPT-Ⅱ)on inner mitochondrial membrane(IMM)regulates long chain fatty acidβ-oxidation,and its abnormality has had more and more attention paid to it by basic and clinical research in NAFLD.The sequences of its peptide chain and DNA nucleotides have been identified,and the catalytic activity of CPT-Ⅱ is affected on its gene mutations,deficiency,enzymatic thermal instability,circulating carnitine level and so on.Recently,the CPT-Ⅱ dysfunction has been discovered in models of liver lipid accumulation.Meanwhile,the malignant transformation of hepatocyte-related CD44^(+) stem T cell activation,high levels of tumor-related biomarkers(AFP,GPC3)and abnormal activation of Wnt3a expression as a key signal molecule of the Wnt/β-catenin pathway run parallel to the alterations of hepatocyte pathology.This review focuses on some of the progress of CPT-Ⅱ inactivity on IMM with liver fatty accumulation as a possible novel pathogenesis for NAFLD in hepatocarcinogenesis.

L-Carnitine拮抗培养心肌细胞缺氧/复氧损伤

目的 探讨L Carnitine对心肌细胞缺氧 /复氧损伤的防护作用及其可能的机制。方法 以原代培养新生鼠心肌细胞建立缺氧 /复氧损伤模型 ,观察不同剂量L Carnitine处理后细胞增殖活性、凋亡细胞百分率及DNA断片化率 ,作为反映L Carnitine对心肌细胞缺氧 /复氧损伤防护作用及其机制的指标。结果 在 5～ 5 0 0 0nmol/L范围内 ,L Carnitine预处理对培养心肌细胞缺氧 /复氧损伤均显示保护效应 ;在 5、5 0及 5 0 0nmol/L时均显著降低DNA断片化率 ;L Carnitine在 5 0nmol/L时与单纯缺氧 /复氧组比较可显著降低凋亡细胞百分率。结论 缺氧 /复氧对心肌细胞的影响之一是可诱导心肌细胞凋亡 ;L Carnitine对培养心肌细胞培养缺氧/复氧损伤具有防护作用 ,其机制可能与抑制缺氧 /复氧诱导细胞凋亡有关。

缺氧复氧对培养仔鼠心肌细胞NRF1和mtTFA表达的影响与L-carnitine保护作用

目的 探讨培养仔鼠心肌细胞缺氧复氧能量代谢损伤的机制及L 肉毒碱 (L carnitine )的保护作用。方法 以原代培养仔鼠心肌细胞建立缺氧复氧损伤模型 ,应用高效液相色谱检测心肌细胞内ATP、ADP、AMP含量 ;应用RT PCR方法检测心肌细胞核呼吸因子 (Nuclearrespiratoryfactor1 ,NRF1 )和线粒体转录因子A(MitochondrialtranscriptionfactorA ,mtTFA)mRNA表达。结果 与正常对照组比较 ,培养的心肌细胞缺氧 2 4h复氧 0、2、4、8h ,心肌细胞ATP、ADP含量均明显下降。与单纯缺氧复氧组比较 ,L carnitine预处理组心肌细胞缺氧复氧后ATP含量明显提升 ;培养的心肌细胞缺氧 2 4h ,NRF1和mtTFAmRNA明显降低 ,复氧 2、4、8h进一步降低。L carnitine预处理使缺氧 2 4h复氧 4h的心肌细胞NRF1和mtTFAmRNA表达分别提升 1 5 %和 2 0 %。结论 心肌细胞缺氧复氧过程中能量代谢明显降低 ,其损伤可能与NRF1和mtTFAmRNA表达下调有关 ;L carnitine对培养仔鼠心肌细胞缺氧复氧能量代谢损伤具有保护作用 ,其机制可能是L carnitine从转录调控水平改善了缺氧复氧过程中心肌细胞的能量代谢。

L-carnitine对缺氧/复氧新生大鼠心肌细胞能量生成及CPT-Ⅱ mRNA表达的影响

目的 探讨L 肉毒碱 (L carnitine ,L Car)对缺氧 复氧培养新生大鼠心肌细胞能量生成的影响及其机制。方法 以原代培养新生大鼠心肌细胞建立缺氧 复氧损伤模型 ,高效液相色谱检测单纯缺氧 复氧以及L Car预处理缺氧 复氧心肌细胞ATP、ADP、AMP生成改变 ;RT PCR方法检测心肌细胞肉毒碱脂酰基转移酶 Ⅱ (carnitinepalmitoyltransferase Ⅱ ,CPT Ⅱ )mRNA表达。结果 与正常对照组比较 ,培养心肌细胞缺氧 2 4h复氧 0、2、4、8h后 ,心肌细胞ATP、ADP均明显下降。与单纯缺氧 复氧组比较 ,L Car预处理组心肌细胞缺氧 复氧后ATP含量明显增高 ;培养心肌细胞缺氧 2 4h后 ,CPT ⅡmRNA表达除复氧 2h有所上升外 ,复氧 4、8h表达渐次降低。L Car预处理使缺氧 2 4h复氧 4h心肌细胞CPT ⅡmRNA表达呈浓度依赖性增高 ,5 0nmol L处理组CPT ⅡmRNA表达显著高于 0nmol L处理组。结论 心肌细胞缺氧 复氧过程中能量生成明显降低 ,其损伤可能与三羧酸循环中呼吸酶CPT Ⅱ表达降低有关 ;L Car对培养仔鼠心肌细胞缺氧复氧损伤具有显著保护作用 ,其机制可能是与L Car从转录调控水平改善CPT Ⅱ合成有关。

A study of the ameliorating effects of carnitine on hepatic steatosis induced by total parenteral nutrition in rats

AIM To investigate the effects of carnitine on ameliorating hepatic steatosis induced by total parenteral nutrition (TPN) in animal model. METHODS Eighteen normal Wistar rats and 19 cirrhotic Wistar rats induced by carbon tetrachloride were randomly divided into three groups, i.e., free access to food and drink (group A), TPN (group B) and TPN+carnitine (group C) for one week, respectively. Hepatic function, histology and its fat content were determined on the 7th day. RESULTS Hepatic triglyceride (TG) and cholesterol (CHO) contents were significantly higher in groups B and C than in group A, and significantly lower in group C than in group B in both normal and cirrhotic rats (all P <0 05). Histopathological examinations revealed that hepatic steatosis was more severe in group B than in group C in both normal and cirrhotic rats. CONCLUSION Carnitine can ameliorate hepatic steatosis associated with TPN in both non cirrhotic and cirrhotic rats.

Effects of L-carnitine in patients with hepatic encephalopathy

AIM： To evaluate the influence of Locarnitine on mental conditions and ammonia effects on patients with hepatic encephalopathy （HE）. METHODS： One hundred and fifty patients （10 patients with alcoholism, 41 patients with hepatitis virus B infection, 78 patients with hepatitis C virus infection, 21 patients with cryptogenetic cirrhosis） meeting the inclusion criteria were randomized into group A receiving a 90-d treatment with L-carnitine （2 g twice a day） or into group B receiving placebo in double blind. RESULTS： At the end of the study period, a significant decrease in NI-14 fasting serum levels was found in patients with hepatic encephalopathy （P〈0.0S） after the treatment with levocarnitine （LC）. Significant differences were also found between symbol digit modalities test and block design in patients with hepatic encephalopathy （P〈0.0S）. CONCLUSION： Results of our study suggest an important protective effect of L-carnitine against ammonia-precipitated encephalopathy in cirrhotic patients.

Mitochondrial carnitine palmitoyl transferase-Ⅱ inactivity aggravates lipid accumulation in rat hepatocarcinogenesis

AIM To investigate the dynamic alteration of mitochondrial carnitine palmitoyl transferase Ⅱ(CPT-Ⅱ) expression during malignant transformation of rat hepatocytes.METHODS Sprague-Dawley male rats were fed with normal, high fat(HF), and HF containing 2-fluorenylacetamide(2-FAA) diet, respectively. According to the Hematoxylin and Eosin staining of livers, rats were divided into control, fatty liver, degeneration, pre-cancerous, and cancerous groups. Liver lipids were dyed with Oil Red O, CPT-Ⅱ alterations were analyzed by immunohistochemistry, and compared with CPT-Ⅱ specific concentration(μg/mg protein). Levels of total cholesterol(Tch), triglyceride(TG), and aminotransferases [alanine aminotransferase(ALT), aspartate aminotransferase(AST)] were determined by the routine methods.RESULTS After intake of HF and/or HF+2-FAA diets, the rat livers showed mass lipid accumulation. The lipid level in the control group was significantly lower than that in other groups. The changes of serum TG and Tch levels were abnormally increasing, 2-3 times more than those in the controls(P < 0.05). During the rat liver morphological changes from normal to cancer development process with hepatocyte injury, serum AST and ALT levels were significantly higher(4-8 times, P < 0.05) than those in the control group. The specific concentration of CPT-Ⅱ in liver tissues progressively decreased during hepatocyte malignant transformation, with the lowest CPT-Ⅱ levels in the cancer group than in any of the other groups(P < 0.05).CONCLUSION Low CPT-Ⅱ expression might lead to abnormal hepatic lipid accumulation, which should promote the malignant transformation of hepatocytes.

Autism and carnitine: A possible link

Patients with autism spectrum disorders(ASD) present deficits in social interactions and communication, they also show limited and stereotypical patterns of behaviors and interests. The pathophysiological bases of ASD have not been defined yet. Many factors seem to be involved in the onset of this disorder. These include genetic and environmental factors, but autism is not linked to a single origin, only. Autism onset can be connected with various factors such as metabolic disorders: including carnitine deficiency. Carnitine is a derivative of two amino acid lysine and methionine. Carnitine is a cofactor for a large family of enzymes: the carnitine acyltransferases. Through their action these enzymes(and L-carnitine) are involved in energy production and metabolic homeostasis. Some people with autism(less than 20%) seem to have L-carnitine metabolism disorders and for these patients, a dietary supplementation with Lcarnitine is beneficial. This review summarizes the available information on this topic.

Enantiomeric Resolution on L-Carnitine Selective Polymers Prepared by Molecular Imprinting

L-carnitine selective polymers were prepared by molecular imprinting using methacrylic acid as the functional monomer. The acid function of the monomer is expected to form hydrogen bond and ionic interactions with the amine function of the target molecule L-carnitine. The imprinted polymers were used as stationary phases in high-performance liquid chromatography (HPLC). It was shown that L-carnitine imprinted polymer exhibited a higher affinity to its template molecule, while the non-imprinted polymer had no affinity to the compounds tested. Racemic carnitine hydrochloride was efficiently resolved on the L-carnitine imprinted polymer, and the separation factor is 1.9.

Progression of diethylnitrosamine-induced hepatic carcinogenesis in carnitine-depleted rats

AIM:To investigate whether carnitine deficiency is a risk factor during the development of diethylnitrosamine (DENA)-induced hepatic carcinogenesis. METHODS:A total of 60 male Wistar albino rats were divided into six groups with 10 animals in each group.Rats in group 1(control group)received a single intraperitoneal(i.p.)injection of normal saline. Animals in group 2(carnitine-supplemented group) were given L-carnitine(200 mg/kg per day)in drinking water for 8 wk.Animals in group 3(carnitine-depleted group)were given D-carnitine(200 mg/kg per day)and mildronate(200 mg/kg per day)in drinking water for 8 wk.Rats in group 4(DENA group)were injected with a single dose of DENA(200 mg/kg,i.p.)and 2 wk later received a single dose of carbon tetrachloride(2 mL/kg) by gavage as 1:1 dilution in corn oil.Animals in group 5(DENA-carnitine depleted group)received the same treatment as group 3 and group 4.Rats in group 6 (DENA-carnitine supplemented group)received the same treatment as group 2 and group 4.RESULTS:Administration of DENA resulted in a significant increase in alanine transaminase(ALT), gamma-glutamyl transferase(G-GT),alkaline phosphatase(ALP),total bilirubin,thiobarbituric acid reactive substances(TBARS)and total nitrate/ nitrite(NOx)and a significant decrease in reduced glutathione(GSH),glutathione peroxidase(GSHPx), catalase(CAT)and total carnitine content in liver tissues.In the carnitine-depleted rat model,DENA induced a dramatic increase in serum ALT,G-GT,ALP and total bilirubin,as well as a progressive reduction in total carnitine content in liver tissues.Interestingly, L-carnitine supplementation resulted in a complete reversal of the increase in liver enzymes,TBARS and NOx,and a decrease in total carnitine,GSH,GSHPx, and CAT induced by DENA,compared with the control values.Histopathological examination of liver tissues confirmed the biochemical data,where L-carnitine prevented DENA-induced hepatic carcinogenesis while D-carnitine-mildronate aggravated DENA-induced hepatic damage. CONCLUSION:Data from this study suggest for the first time that:(1)carnitine deficiency is a risk factor and should be viewed as a mechanism in DENA- induced hepatic carcinogenesis;(2)oxidative stress plays an important role but is not the only cause of DENA-induced hepatic carcinogenesis;and(3) long-term L-carnitine supplementation prevents the development of DENA-induced liver cancer.

Decrease of serum carnitine levels in patients with or without gastrointestinal cancer cachexia

AIM： To evaluate the levels of serum carnitine in patients with cancer in digestive organs and to compare them with other cancers in order to provide new insights into the mechanisms of cachexia. METHODS： Fifthy-five cachectic patients with or without gastrointestinal cancer were enrolled in the present study. They underwent routine laboratory investigations, including examination of the levels of various forms of carnitine present in serum （i.e., long-chain acylcarnitine, short-chain acylcarnitine, free carnitine, and total carnitine）. These values were compared with those found in 60 cancer patients in good nutritional status as well as with those of 30 healthy control subjects. RESULTS： When the cachectic patients with gastrointestinal cancer were compared with the cachectic patients without gastrointestinal cancer, the difference was -6.8 μmol/L in free carnitine （P 〈 0.005）, 0.04 μmol/ L in long chain acylcarnitine （P 〈 0.05）, 8.7 μmol/L in total carnitine （P 〈 0.001）. In the cachectic patients with or without gastrointestinal cancer, the difference was 12.2 μmol/L in free carnitine （P 〈 0.001）, 4.60 μmol/L in short chain acylcarnitine （P 〈 0.001）, and 0.60 μmol/L in long-chain acylcarnitine （P 〈 0.005） and 17.4 μmol/L in total carnitine （P 〈 0.001）. In the cachectic patients with gastrointestinal cancer and the healthy control subjects, the difference was 15.5 μmol/L in free carnitine （P 〈 0.001）, 5.2 μmol /L in short-chain acylcarnitine （P 〈 0.001）, 1.0 μmol/L in long chain acylcarnitine （P 〈 0.001）, and 21.8 μmol/L in total carnitine （P 〈 0.001）. CONCLUSION： Low serum levels of carnitine in terminal neoplastic patients are decreased greatly due to the decreased dietary intake and impaired endogenous synthesis of this substance. These low serum carnitine levels also contribute to the progression of cachexia in cancer patients.

Plasma carnitine ester profile in adult celiac disease patients maintained on long-term gluten free diet

AIM： To determine the fasting plasma carnitine ester in patients with celiac disease. METHODS： We determined the fasting plasma carnitine ester profile using ESI triple quadrupol mass spectrometry in 33 adult patients with biopsy-confirmed maturity onset celiac disease maintained on long term gluten free diet. RESULTS： The level of free camibine did not differ as the celiac disease patients were compared with the healthy controls, whereas the acetylcarnitine level was markedly reduced （4.703± 0.205 vs 10.227 ± 0.368 nmol/mL, P〈0.01）. The level of propionylcarnitine was 61.5%, butyrylcarnitine 56.9%, hexanoylcarnitine 75%, octanoylcarnitine 71.1%, octenoylcarnitine 52.1%, decanoylcarnitine 73.1%, cecenoylcarnitine 58.3%, lauroylcarnitine 61.5%, miristoylcarnitine 66.7%, miristoleylcarnitine 62.5% and oleylcarnitine 81.1% in the celiac disease patients compared to the control values, respectively （P〈0.01）. CONCLUSION： The marked decrease of circulating acetylcarnitine with 50-80 % decrease of 11 other carnitine esters shows that the carnitine ester metabolism can be influenced even in clinically asymptomatic and well being adult celiac disease patients, and gluten withdrawal alone does not necessarily normalize all elements of the disturbed carnitine homeostasis.

Changes of plasma fasting carnitine ester profile in patients with ulcerative colitis

AIM： To determine the plasma carnitine ester profile in adult patients with ulcerative culitis （UC） and compared with healthy control subjects. METHOD： Using ESI triple quadrupole tandem mass spectrometry, the carnitine ester profile was measured in 44 patients with UC and 44 age- and sex-matched healthy controls. RESULTS： There was no significant difference in the fasting free carnitine level between the patients with UC and the healthy controls. The fasting propionyl- （0.331 ± 0.019 vs 0.392 ± 0.017 μmol/L）, butyryl- （0.219 ± 0.014 vs 0.265 ± 0.012）, and isovalerylcarniUne （0.111 ± 0.008 vs 0.134 ± 0.008） levels were decreased in the UC patients. By contrast, the level of octanoyl- （0.147 ± 0.009 vs 0.114 ± 0.008）, decanoyl- （0.180 ± 0.012 vs 0.137 ± 0.008）, myristoyl- （0.048 ± 0.003 vs 0.039 ± 0.003）, palmitoyl- （0.128 ± 0.006 vs 0.109 ± 0.004）, palmitoleyl- （0.042±0.003 vs 0.031 ± 0.002） and oleylcarnitine （0.183 ± 0.007 vs 0.163 ± 0.007; P 〈 0.05 in all comparisons） were increased in the patients with UC. CONCLUSION： Our data suggest selective involvement of the carnitine esters in UC patients, probably due to their altered metabolism.

Diabetic Cardiovascular Risk and Carnitine Deficiency <br/>—Carnitine Deficiency in Clinical Diabetes Mellitus

Background: Type 1 diabetes mellitus increases the risk of coronary heart disease. The Pittsburgh IDDM morbidity and mortality study reported greater than 10 fold coronary heart disease mortality compared with US national data?[1]. Adults with diabetes have heart disease death rates 2 to 4 times higher than adults without diabetes [2]. Diabetic cardiomyopathy explains much of this survival difference and carnitine deficiency is a cause of cardiomyopathy. Research Design and Methods: Adult subjects (40) with type 1 diabetes mellitus were seen for a routine annual visit having no clinical complaints. Fasting serum samples were collected for annual chemistries and the measurement of carnitine. Results: The mean total (40.8 ± 8.8) [40 - 80 nmol/ml] and free (32.9 ± 7.9) [30 - 60 nmol/ml] carnitine levels for this group included 43% low total and 28% low free carnitine. The mean esterified/free (E/F) carnitine ratio (0.25 ± 0.09) for this group was elevated indicating carnitine insufficiency. Conclusions: Fatty acids are the primary energy source for diabetic heart muscle, and carnitine is essential for intracellular fatty acid transport and ATP production. Therefore, mild carnitine deficiency can compromise fatty acid energy production in a failing heart. Carnitine deficiency in subjects at high risk for cardiovascular failure is a possible unrecognized reason for the 4 fold increased death rate in patients with type 1 diabetes. Supplementation with oral carnitine could reduce that increased risk of heart failure, in patients with type 1 diabetes. Intravenous carnitine may be life saving when managing acute cardiac failure in patients with diabetes mellitus. Normal carnitine levels in patients with type 1 diabetes may provide a biochemical environment that prevents the long recognized idiopathic heart failure that occurs in insulin requiring diabetics as first reported in the 1974 Framingham Study.

Beneficial effect of butyrate, Lactobacillus casei and L-carnitine combination in preference to each in experimental colitis

AIM: To investigate the beneficial effect of the combination of butyrate, Lactobacillus casei, and L-carnitine in a rat colitis model.

L-carnitine protects C2C12 cells against mitochondrial superoxide overproduction and cell death

AIM To identify and characterize the protective effect that L-carnitine exerted against an oxidative stress in C2C12 cells.METHODS Myoblastic C2C12 cells were treated with menadione, a vitamin K analog that engenders oxidative stress, and the protective effect of L-carnitine(a nutrient involved in fatty acid metabolism and the control of the oxidative process), was assessed by monitoring various parameters related to the oxidative stress, autophagy and cell death. RESULTS Associated with its physiological function, a muscle cell metabolism is highly dependent on oxygen and may produce reactive oxygen species(ROS), especially under pathological conditions. High levels of ROS are known to induce injuries in cell structure as they interact at many levels in cell function. In C2C12 cells, a treatment with menadione induced a loss of transmembrane mitochondrial potential, an increase in mitochondrial production of ROS; it also induces autophagy and was able to provoke cell death. Pre-treatment of the cells with L-carnitine reduced ROS production, diminished autophagy and protected C2C12 cells against menadione-induced deleterious effects. CONCLUSION In conclusion, L-carnitine limits the oxidative stress in these cells and prevents cell death.

The Protective Effect of L-carnitine on Ischemia-reperfusion Heart

To investigate the protective effect of L-carnitine on myocardial ischemia-reperfusion injury in rat heart,all harvested isolated hearts were perfused on Langendorff apparatus with oxygenized K-H solution for 20 min. The hearts were then exposed to ischemia for 30 min. Following the ischemia the hearts were re-perfused with K-H solution for 120 min to serve as the control group A. Either 5 or 10 mmol/L of L-carnitine was added into the K-H solution for 20 min at the beginning of reperfusion to generate group B and group C, respectively. The derivatives of the intraventricular pressure curve （DP/DT）, left ventricular developed pressure （LVDP）, and coronary flux were monitored during the entire experiment. The levels of ATP, hepatin, malondialdehyde （MDA）, and superoxide dismutase （SOD） in tissue, and lactic dehydrogenase （LDH）, creatine phosphate kinase （CPK）, malondialdehyde （MDA）, and superoxide dismutase （SOD） concentration in the coronary efflux were all measured. Compared with the control group, the treatment with L-carnitine resulted in better results, i. e. , higher DP/DTmax and LVDP. At the same time, ventricular fibrillation was reduced, and the levels of ATP, hepatin and SOD were all elevated. However, the concentrations of MDA, CPK and LDH were all reduced. In conclusion, L-carnitine has a protective effect on ischemia-reperfusion injury, which is partly due to its prevention of energy loss and its antioxidant activity.

Development and validation of a UPLC–MS/MS assay for the determination of gemcitabine and its L-carnitine ester derivative in rat plasma and its application in oral pharmacokinetics

A simple and rapid UPLC–MS/MS method to simultaneously determine gemcitabine and its L-carnitine ester derivative(2’-deoxy-2’, 2’-difluoro-N-((4-amino-4-oxobutanoyl) oxy)-4-(trimethyl amm-onio) butanoate-cytidine, JDR) in rat plasma was developed and validated.The conventional plasma sample preparation method of nucleoside analogues is solidphase extraction(SPE) which is time-consuming and cost-expensive. In this study, gradient elution with small particles size solid phase was applied to effectively separate gemcitabine and JDR, and protein precipitation pretreatment was adopted to remove plasma protein and extract the analytes with high recovery(>81%). Method validation was performed as per the FDA guidelines, and the standard curves were found to be linear in the range of 5–4000 ng/ml for JDR and 4–4000 ng/ml for gemcitabine, respectively. The lower limit of quantitation(LLOQ)of gemcitabine and JDR was 4 and 5 ng/ml, respectively. The intra-day and inter-day precision and accuracy results were within the acceptable limits. Finally, the developed method was successfully applied to investigate the pharmacokinetic studies of JDR and gemcitabine after oral administration to rats.

Acetyl-L-carnitine:An Effective Antioxidant against Cryo-damage on Human Spermatozoa with Asthenospermia

A variety of natural and artificial cryoprotectant extenders have been explored to enhance sperm recovery following cryopreservation-thawing process. The current investigation is aimed at evaluating the effect of acetyl-L-carnitine on human spermatozoa and reactive species oxygen（ROS） level after freezing-thawing process. The spermatozoa were collected from 35 male patients diagnosed as having asthenospermia. The cryopreservation of human spermatozoa treated with acetyl-L-carnitine at different concentrations（group B： 2.5 mmol/L, group C： 7.5 mmol/L, group D： 15 mmol/L） was compared with control（group A： no acetyl-L-carnitine given）. For the frozen-thawed spermatozoa, the viability, motility and DNA integrity were measured by comet assay, acrosome integrity by FITC-PNA staining and ROS level was determined in each group. The results showed that there were no significant differences in motility and viability between group A and group B, while the motility and viability of spermatozoa in group C and group D were significantly increased as compared with those in group A. As compared with group A, the values for DNA integrity parameters including comet rate（CR）, tail DNA percentage（TD）, tail length（TL） and Oliver tail moment（OTM） were significantly reduced in group C and group D. Group C and group D also displayed a higher proportion of intact acrosome than group A. No significant difference in ROS level was found between group A and group B, while with the increase in acetyl-L-carnitine concentration, the ROS level in groups C and D was significantly reduced as compared with that in group A. In conclusion, acetyl-L-carnitine at a concentration of 7.5 mmol/L is an effective antioxidant against cryo-damage on post-thawed human spermatozoa.