Hypoxanthine Concentrations Research Articles

Quality Consistency Evaluation of Chemical Composition and Pharmacology of Pheretima aspergillum Dispensing Granules and Traditional Decoction Based on HPLC, GC-IMS, and Animal Experiments.

This study investigates the consistency of quality between the traditional decoction (TD) of Pheretima aspergillum and its dispensing granule decoction (DGD) by examining their chemical composition and antithrombotic efficacy. We first determined the nucleoside components, protein content, and volatile compounds in 10 batches of TD and 9 batches of DGD sourced from three manufacturers using high-performance liquid chromatography (HPLC), UV-vis spectrophotometry, and gas chromatography ion mobility spectrometry (GC-IMS). Next, we assessed antithrombotic efficacy by measuring the relative length of tail thrombosis and calculating the thrombus inhibition rates at 24 and 48h. Our comprehensive analysis revealed that the concentrations of hypoxanthine, uridine, inosine, adenosine, and proteins in TD were significantly higher than those in DGD. Moreover, the types and concentrations of volatile compounds in TD and DGD exhibited substantial differences, with 19 volatile compounds identified as differentially present between the two decoctions. Despite these compositional differences, both decoction types demonstrated equivalent antithrombotic efficacy. Overall, the quality of DGD from manufacturers A and B aligned closely with that of TD. However, TD exhibited a higher overall quality compared to DGD, while both decoctions maintained consistent antithrombotic efficacy.

Associations between muscle quality and whole-body vibration exercise-induced changes in plasma hypoxanthine following an oral glucose load in healthy male subjects

Blood levels of hypoxanthine (HX) have been suggested as potential biomarkers associated with intramuscular metabolic dynamics in response to exercise. This pilot randomized crossover trial (UMIN000036520) aimed to investigate the changes in plasma HX after whole-body vibration exercise (WBVE) and their relationships with body composition and muscle-related parameters, enrolling eighteen healthy male volunteers. In the WBVE-alone intervention, the study subjects performed 20-min of WBVE. In the OGTT → WBVE intervention, a 75-g oral glucose load (OGL) was administered 30 min prior to the start of the WBVE intervention. Blood samples were collected before the start and 10 min after the end of WBVE in both interventions. WBVE resulted in a significant increase in plasma HX levels, which was accompanied by increased blood ammonia, pyruvic acid, and lactic acid levels. The HX increase following WBVE was suppressed by prior OGL. In the WBVE-alone intervention, there were no significant correlations between the post-WBVE changes in plasma HX (ΔHX) levels and any of the clinical parameters. On the other hand, in the OGTT → WBVE intervention, ΔHX showed significant negative correlations with muscle mass (ρ = -0.62, p = 0.01), strength (ρ = -0.71, p = 0.005), and muscle quality (ρ = -0.81, p = 0.0007) in the legs. In conclusion, these findings suggest possible associations between post-WBVE increases in plasma HX levels and muscle status, particularly under the glucose-supplemented condition. The measurement of plasma HX concentrations following WBVE may have clinical applications in the identification of high-risk populations for sarcopenia.

Simultaneous quantitative analysis of multiple metabolites using label-free surface-enhanced Raman spectroscopy and explainable deep learning

Metabolites serve as vital biomarkers, reflecting physiological and pathological states and offering insights into disease progression and early detection. This study introduces an advanced analytical technique integrating label-free Surface-Enhanced Raman Spectroscopy (SERS) with deep learning, and leverages SHAP (SHapley Additive exPlanations) to provide a visual interpretative analysis of the predictive rationale of the deep learning model, facilitating simultaneous detection and quantitative analysis of multiple metabolites. Monolayer silver nanoparticle SERS substrates were fabricated via a triple-phase interfacial self-assembly method, which captured complex spectral information of target metabolites in mixed solutions. A custom-built deep neural network model with multi-channel feature extraction was employed to predict the concentrations of uric acid (R2=0.976), xanthine (R2=0.971), hypoxanthine (R2=0.977), and creatinine (R2=0.940). The method's scalability was validated as the performance remained consistent with an increasing number of simultaneous targets. This approach offers a sensitive, cost-effective, and rapid alternative for metabolite analysis, with significant implications for clinical diagnostics and personalized medicine.

A Lifelike guided journey through the pathophysiology of pulmonary hypertension—from measured metabolites to the mechanism of action of drugs

IntroductionPulmonary hypertension (PH) is a pathological condition that affects approximately 1% of the population. The prognosis for many patients is poor, even after treatment. Our knowledge about the pathophysiological mechanisms that cause or are involved in the progression of PH is incomplete. Additionally, the mechanism of action of many drugs used to treat pulmonary hypertension, including sotatercept, requires elucidation.MethodsUsing our graph-powered knowledge mining software Lifelike in combination with a very small patient metabolite data set, we demonstrate how we derive detailed mechanistic hypotheses on the mechanisms of PH pathophysiology and clinical drugs.ResultsIn PH patients, the concentration of hypoxanthine, 12(S)-HETE, glutamic acid, and sphingosine 1 phosphate is significantly higher, while the concentration of L-arginine and L-histidine is lower than in healthy controls. Using the graph-based data analysis, gene ontology, and semantic association capabilities of Lifelike, led us to connect the differentially expressed metabolites with G-protein signaling and SRC. Then, we associated SRC with IL6 signaling. Subsequently, we found associations that connect SRC, and IL6 to activin and BMP signaling. Lastly, we analyzed the mechanisms of action of several existing and novel pharmacological treatments for PH. Lifelike elucidated the interplay between G-protein, IL6, activin, and BMP signaling. Those pathways regulate hallmark pathophysiological processes of PH, including vasoconstriction, endothelial barrier function, cell proliferation, and apoptosis.DiscussionThe results highlight the importance of SRC, ERK1, AKT, and MLC activity in PH. The molecular pathways affected by existing and novel treatments for PH also converge on these molecules. Importantly, sotatercept affects SRC, ERK1, AKT, and MLC simultaneously. The present study shows the power of mining knowledge graphs using Lifelike’s diverse set of data analytics functionalities for developing knowledge-driven hypotheses on PH pathophysiological and drug mechanisms and their interactions. We believe that Lifelike and our presented approach will be valuable for future mechanistic studies of PH, other diseases, and drugs.

A smartphone-assisted portable sensing hydrogel modules based on UCNPs and Co3O4 NPs for fluorescence quantitation of hypoxanthine in aquatic products

Hypoxanthine is a promising index for evaluating the freshness of various aquatic products. Combined the hydrogels containing upconversion nanoparticles (UCNPs), Co3O4 NPs, and N-ethyl-N-(3-sulfopropyl)-3-methylaniline sodium salt/4-amino-antipyrine (TOPS/4-AAP) with a smartphone, a portable sensor was developed for the convenient, sensitive detection of hypoxanthine. With the H2O2 from xanthine oxidase (XOD)-catalyzed reactions of hypoxanthine, the fluorescence of UCNPs was effectively quenched by the purple product produced from the oxidization of TOPS/4-AAP catalyzed by Co3O4 NPs exhibiting peroxidase activity, among which the color change could be transformed into digital signals for quantification of hypoxanthine. The Green value in the RGB analysis of the fluorescence image was negatively proportional to hypoxanthine concentration in the range of 2.5-20mg/L with a detection limit of 0.69mg/L and a quantitation limit of 2.30mg/L. Finally, this sensor was applied for hypoxanthine detection in real aquatic products, showing potential application for freshness evaluation of aquatic products.

Targeted Metabolomics Highlights Dramatic Antioxidant Depletion, Increased Oxidative/Nitrosative Stress and Altered Purine and Pyrimidine Concentrations in Serum of Primary Myelofibrosis Patients.

To date, little is known concerning the circulating levels of biochemically relevant metabolites (antioxidants, oxidative/nitrosative stress biomarkers, purines, and pyrimidines) in patients with primary myelofibrosis (PMF), a rare form of myeloproliferative tumor causing a dramatic decrease in erythropoiesis and angiogenesis. In this study, using a targeted metabolomic approach, serum samples of 22 PMF patients and of 22 control healthy donors were analyzed to quantify the circulating concentrations of hypoxanthine, xanthine, uric acid (as representative purines), uracil, β-pseudouridine, uridine (as representative pyrimidines), reduced glutathione (GSH), ascorbic acid (as two of the main water-soluble antioxidants), malondialdehyde, nitrite, nitrate (as oxidative/nitrosative stress biomarkers) and creatinine, using well-established HPLC method for their determination. Results showed that PMF patients have dramatic depletions of both ascorbic acid and GSH (37.3- and 3.81-times lower circulating concentrations, respectively, than those recorded in healthy controls, p < 0.0001), accompanied by significant increases in malondialdehyde (MDA) and nitrite + nitrate (4.73- and 1.66-times higher circulating concentrations, respectively, than those recorded in healthy controls, p < 0.0001). Additionally, PMF patients have remarkable alterations of circulating purines, pyrimidines, and creatinine, suggesting potential mitochondrial dysfunctions causing energy metabolism imbalance and consequent increases in these cell energy-related compounds. Overall, these results, besides evidencing previously unknown serum metabolic alterations in PMF patients, suggest that the determination of serum levels of the aforementioned compounds may be useful to evaluate PMF patients on hospital admission for adjunctive therapies aimed at recovering their correct antioxidant status, as well as to monitor patients' status and potential pharmacological treatments.

K2Cr2O7-induced DNA damage in HT1080 cells: Electrochemical signal response mechanism

The existing DNA damage detection technology cannot meet the current detection requirements. It is critical to build new methods and discover novel biomarkers. In this study, alkaline comet and 8-OHDG ELISA assays were used to identify DNA damage in HT-1080 cells exposed to K2Cr2O7, and electrochemical behaviors of HT-1080 cells with DNA damage was studied. With an increase in K2Cr2O7 exposure time, two electrochemical signals from HT-1080 cells at 0.69 and 1.01V steadily grew before decreasing after reaching their highest values. The electrochemical signal's initial response time and peak time decreased as the concentration of K2Cr2O7 increased. The duration of the high dose group was 0.5 and 1h, while the low dose group was 1.5 and 6h. Western blotting analysis revealed that DNA damage increased the expression of proteins involved in catabolism and de novo purine synthesis, particularly de novo purine synthesis. Expressions of PRPP amidotransferase, IMPDH, and ADA were all higher than those of ADSS, XOD, and GDA, which resulted in larger concentrations of hypoxanthine, guanine, and xanthine, and in turn improved electrochemical signaling. These findings suggest that intracellular purine identified by linear scan voltammetry is predicted to evolve as a marker of early DNA damage.

Hypoxanthine in the microenvironment can enable thiopurine resistance in acute lymphoblastic leukemia.

Acute lymphoblastic leukemia (ALL) is the most common pediatric malignancy, with relapse being a major obstacle to successful treatment. Our understanding of the mechanisms driving chemotherapy resistance and ultimately relapse in leukemia remains incomplete. Herein, we investigate the impact of the tumor microenvironment on leukemia cell drug responses using human plasma-like media (HPLM), designed to mimic physiological conditions more accurately ex vivo. We demonstrate that while most chemotherapeutics maintain an efficacy in HPLM comparable to standard tissue culture media, the thiopurines 6-mercaptopurine (6-MP) and 6-thioguanine (6-TG) exhibit significantly reduced potency and efficacy against both B- and T- leukemia cells in HPLM. By merging our understanding of thiopurines' mechanism of action with the metabolites supplemented in HPLM compared to standard media, we proposed and subsequently validated the hypothesis that hypoxanthine, a purine derivative, is responsible for conferring resistance to the thiopurines. Importantly, the concentration of hypoxanthine required for resistance is comparable to physiological levels found in vivo, supporting clinical relevance. Our findings demonstrate the utility of a more physiologic media in identifying and characterizing mechanisms by which the microenvironment can enable resistance. Understanding such interactions may inform strategies to overcome drug resistance and improve therapeutic outcomes in pediatric leukemia.

Research on sweat metabolomics of athlete's fatigue induced by high intensity interval training.

Objective: Sweat is an important specimen of human metabolism, which can simply and non-invasively monitor the metabolic state of the body, and its metabolites can be used as biomarkers for disease diagnosis, while the changes of sweat metabolites before and after exercise-induced fatigue are still unclear. Methods: In this experiment, high-performance chemical isotope labeling liquid chromatography-mass spectrometry (LC-MS) was used to metabolomic 28 sweat samples before and after exercise-induced fatigue of 14 long-distance runners, also IsoMS PRO and SPSS22.0 software were used to analyze the metabolite changes and differential metabolic pathways. Results: A total of 446 metabolites with high confidence were identified, and the sweat metabolome group before and after high-intensity interval exercise-induced fatigue was obvious, among which the upregulated differential metabolites mainly included hypoxanthine, pyruvate, several amino acids, etc., while the downregulated differential metabolites mainly included amino acid derivatives, vitamin B6, theophylline, etc. Conclusion: The change of hypoxanthine concentration in sweat can be used as a good biomarker for the diagnosis of exercise-induced fatigue, while the change of pyruvate content in sweat can be used as a discriminant index for the energy metabolism mode of the body before and after exercise. The main metabolic pathways involved in differential metabolites produced before and after HIIT exercise-induced fatigue are purine metabolism and amino acid metabolism.

Exploiting Purine as an Internal Standard for SERS Quantification of Purine Derivative Molecules Released by Bacteria.

Surface-enhanced Raman scattering (SERS) is a highly sensitive technique used in diverse biomedical applications including rapid antibiotic susceptibility testing (AST). However, signal fluctuation in SERS, particularly the widespread of signals measured from different batches of SERS substrates, compromises its reliability and introduces potential errors in SERS-AST. In this study, we investigate the use of purine as an internal standard (IS) to recalibrate SERS signals and quantify the concentrations of two important purine derivatives, adenine and hypoxanthine, which are the most important biomarkers used in SERS-AST. Our findings demonstrate that purine IS effectively mitigates SERS signal fluctuations and enables accurate prediction of adenine and hypoxanthine concentrations across a wide range (5 orders of magnitude). Calibrations with purine as an IS outperform those without, exhibiting a 10-fold increase in predictive accuracy. Additionally, the calibration curve obtained from the first batch of SERS substrates remains effective for 64 additional substrates fabricated over a half-year period. Measurements of adenine and hypoxanthine concentrations in bacterial supernatants using SERS with purine IS closely align with the liquid chromatography-mass spectrometry results. The use of purine as an IS offers a simple and robust platform to enhance the speed and accuracy of SERS-AST, while also paving the way for in situ SERS quantification of purine derivatives released by bacteria under various stress conditions.

Inulin Supplementation Modulates the Hepatic Transcriptome, Metabolome, and Ferritin Content in Ovariectomized Rats.

Liver is an important metabolic organ regulating whole-body homeostasis. This study aims to investigate how prebiotic-induced changes in the metabolic activity of the gut microbiome (GM) and dietary calcium depletion modulates the hepatic metabolome and transcriptome. The serum metabolome, liver metabolome, and transcriptome are determined on samples from ovariectomized (OVX) rats fed a control diet (Control, n = 7), a control diet supplemented with 5% w/w inulin (Inulin, n = 7), or a calcium-deficient diet (CaDef, n = 7). Inulin fortification is associated with higher serum concentrations of acetate, 3-hydroxybutyrate, and reduced concentration of dimethyl sulfone, revealing that changes in the metabolic activity of the GM are reflected in circulating metabolites. Metabolomics also reveal that the inulin-fortified diet results in lower concentrations of hepatic glutamate, serine, and hypoxanthine while transcriptomics reveal accompanying effects on the hepatic expression of ferric iron binding-related genes. Inulin fortification also induces effects on the hepatic expression of genes involved in olfactory transduction, suggesting that prebiotics regulate liver function through yet unidentified mechanisms involving olfactory receptors. Inulin ingestion impacts hepatic gene expression and is associated with an upregulation of ferritin synthesis-related genes and liver ferritin content.

Effects of Dietary Chlorogenic Acid Supplementation on Growth Performance, Meat Quality, and Muscle Flavor Substances in Finishing Pigs.

With the prohibition of antibiotics in feed, certain phytocompounds have been widely studied as feed additives. Chlorogenic acid (CGA), a natural polyphenol found in plants, possesses anti-inflammatory, antioxidant, and metabolic regulatory features. The objective of this study was to investigate the effects of dietary chlorogenic acid supplementation on growth performance and carcass traits, as well as meat quality, nutrient value and flavor substances of Duroc × Landrace × Yorkshire (DLY) pigs. Forty healthy DLY pigs (initial body weight (BW): 26.69 ± 0.37) were allotted to four treatment groups and were fed with the control diet, which was supplemented with 25 mg kg-1, 50 mg kg-1, and 100 mg kg-1 CGA, respectively. The trial lasted 100 days. The results suggested that dietary CGA supplementation had no effect (p < 0.05) on the average daily gain (ADG) and feed conversion ratio (FC). Herein, it was found that 50 mg kg-1 CGA-containing diet not only increased the dressing percentage and perirenal fat, but also reduced the rate of muscular pH decline (p < 0.05). In the longissimus thoracis (LT) muscle, the myofiber-type-related genes such as the MyHC IIa and MyHC IIX mRNA levels were increased by 100 mg kg-1 CGA. The results also indicated that the 100 mg kg-1 CGA-containing diet increased the content of crude fat, glycogen, total amino acids, and flavor amino acids, but decreased the inosine and hypoxanthine concentration in LT (p < 0.05). Meanwhile, the lipogenic gene ACC1 mRNA level was elevated by 50 mg kg-1 CGA. Instead, 100 mg kg-1 CGA downregulated the expression level of NT5C2, an enzyme responsible for inosine-5'-monophosphate (IMP) degradation. Additionally, 100 mg kg-1 CGA decreased the malondialdehyde (MDA) content, but increased the glutathione peroxidase (GSH-Px) content as well as antioxidant gene (HO-1, NQO-1, NRF2) mRNA levels in LT muscle. These findings showed that dietary CGA could partly improve carcass traits and muscle flavor without negatively affecting growth performance, and the underlying mechanism may be due to the antioxidant properties induced by CGA.

High-Accuracy Renal Cell Carcinoma Discrimination through Label-Free SERS of Blood Serum and Multivariate Analysis.

Renal cell carcinoma (RCC) represents the sixth most frequently diagnosed cancer in men and is asymptomatic, being detected mostly incidentally. The apparition of symptoms correlates with advanced disease, aggressive histology, and poor outcomes. The development of the Surface-Enhanced Raman Scattering (SERS) technique opened the way for investigating and detecting small molecules, especially in biological liquids such as serum or blood plasma, urine, saliva, and tears, and was proposed as a simple technique for the diagnosis of various diseases, including cancer. In this study, we investigated the use of serum label-free SERS combined with two multivariate analysis tests: Principal Component Analysis combined with Linear Discriminate Analysis (PCA-LDA) and Supported Vector Machine (SVM) for the discrimination of 50 RCC cancer patients from 45 apparently healthy donors. In the case of LDA-PCA, we obtained a discrimination accuracy of 100% using 12 principal components and a quadratic discrimination function. The accuracy of discrimination between RCC stages was 88%. In the case of the SVM approach, we obtained a training accuracy of 100%, a validation accuracy of 92% for the discrimination between RCC and controls, and an accuracy of 81% for the discrimination between stages. We also performed standard statistical tests aimed at improving the assignment of the SERS vibration bands, which, according to our data, are mainly due to purinic metabolites (uric acid and hypoxanthine). Moreover, our results using these assignments and Student's t-test suggest that the main differences in the SERS spectra of RCC patients are due to an increase in the uric acid concentration (a conclusion in agreement with recent literature), while the hypoxanthine concentration is not statistically different between the two groups. Our results demonstrate that label-free SERS combined with chemometrics holds great promise for non-invasive and early detection of RCC. However, more studies are needed to validate this approach, especially when combined with other urological diseases.

MnO2 in-situ coated upconversion nanosystem for turn-on fluorescence detection of hypoxanthine in aquatic products

Hypoxanthine concentration is a potential indicator to evaluate the freshness in the early post-mortem of several aquatic products. Based on MnO2 in-situ coated upconversion nanoparticles (UCNPs) and xanthine oxidase (XOD), a novel sensor was conducted for the efficient, sensitive determination of hypoxanthine. In this strategy, upconversion fluorescence quenched by MnO2 would be restored by H2O2 and uric acid (UA), two products from the XOD-catalyzed reactions of hypoxanthine. Through pretreatment with short-time heating and alkylation by N-ethylmaleimide (NEM) to avoid potential interference from reducing substances in the food matrix, this method exhibited satisfactory selectivity. The fluorescence intensity of green emission Igreen was positively proportional to hypoxanthine concentration at a wide range of 0.5-50mg/L with a detection limit of 0.14mg/L. Moreover, this convenient method was employed to quantify the hypoxanthine in fish, shrimp, and shellfish samples, showing excellent potential for the application in quality control of aquatic products.

The integrated analysis strategy of unstable hypoxanthine, a potential quality marker in Shuxuetong injection based on standard addition method and multi-level pharmacokinetics by LC-MS/MS

Objective: As an injection made from traditional Chinese medicine, Shuxuetong (SXT) injection is used for the treatment of ischemic stroke. Hypoxanthine is regarded as one of its potential quality markers. The purpose of this study is to lay the foundation for the quality control of SXT injection by the analysis of the quantitation and pharmacokinetic behavior for hypoxanthine. Methods: A quantitative method of hypoxanthine in SXT injection based on standard addition method by liquid chromatography-tandem mass spectrometry (LC-MS/MS) was established for the first time. On the other hand, a determination method of hypoxanthine in rat plasma samples after administration of SXT was also successfully established based on LC-MS/MS. Results: It was found that the content of hypoxanthine was higher using conventional liquid-mass spectrometry technology compared to the application of LC-MS/MS combined standard addition method in the same batch of SXT injection. The ratio of low, medium and high dose of intravenous SXT were 1: 2: 4, and the AUC0-t was 848.34 ± 324.53, 1483.94 ± 497.74, and 3074.84 ± 910.29 μg·h/L, respectively. AUC0-t shows good linear dose-dependent relationship. Conclusions: The influences of endogenous substance tend to be eliminated through calibrating the concentration level of the target compound by the introduction of standard addition method. The added allopurinol could inhibit the conversion of the target compound, and ensure the accuracy of the detection during the pharmacokinetic studies. “Blank biological matrix” obtained from pretreatment of blank plasma successfully distinguished endogenous and drug-derived hypoxanthine. There is a good linear relationship between the blood concentration of intravenous hypoxanthine and the dosage of administration. Similarly, there was no drug accumulation in the multiple medium-dosage group, which is similar to the pharmacokinetic characteristics of the single medium-dosage group.

Surface-Enhanced Raman Analysis of Uric Acid and Hypoxanthine Analysis in Fractionated Bodily Fluids.

In recent years, the disease burden of hyperuricemia has been increasing, especially in high-income countries and the economically developing world with a Western lifestyle. Abnormal levels of uric acid and hypoxanthine are associated with many diseases, and therefore, to demonstrate improved methods of uric acid and hypoxanthine detection, three different bodily fluids were analysed using surface-enhanced Raman spectroscopy (SERS) and high-performance liquid chromatography (HPLC). Gold nanostar suspensions were mixed with series dilutions of uric acid and hypoxanthine, 3 kDa centrifugally filtered human blood serum, urine and saliva. The results show that gold nanostars enable the quantitative detection of the concentration of uric acid and hypoxanthine in the range 5-50 μg/mL and 50-250 ng/mL, respectively. The peak areas of HPLC and maximum peak intensity of SERS have strongly correlated, notably with the peaks of uric acid and hypoxanthine at 1000 and 640 cm-1, respectively. The r2 is 0.975 and 0.959 for uric acid and hypoxanthine, respectively. Each of the three body fluids has a number of spectral features in common with uric acid and hypoxanthine. The large overlap of the spectral bands of the SERS of uric acid against three body fluids at spectra peaks were at 442, 712, 802, 1000, 1086, 1206, 1343, 1436 and 1560 cm-1. The features at 560, 640, 803, 1206, 1290 and 1620 cm-1 from hypoxanthine were common to serum, saliva and urine. There is no statistical difference between HPLC and SERS for determination of the concentration of uric acid and hypoxanthine (p > 0.05). For clinical applications, 3 kDa centrifugal filtration followed by SERS can be used for uric acid and hypoxanthine screening is, which can be used to reveal the subtle abnormalities enhancing the great potential of vibrational spectroscopy as an analytical tool. Our work supports the hypnosis that it is possible to obtain the specific concentration of uric acid and hypoxanthine by comparing the SER signals of serum, saliva and urine. In the future, the analysis of other biofluids can be employed to detect biomarkers for the diagnosis of systemic pathologies.

Gelatin-based smart film incorporated with nano cerium oxide for rapid detection of shrimp freshness

Gelatin-based smart film incorporated with nano cerium oxide for rapid detection of shrimp freshness

Metabolic Signature of Energy Metabolism Alterations and Excess Nitric Oxide Production in Culture Media Correlate with Low Human Embryo Quality and Unsuccessful Pregnancy.

Notwithstanding the great improvement of ART, the overall rate of successful pregnancies from implanted human embryos is definitely low. The current routine embryo quality assessment is performed only through morphological criteria, which has poor predictive capacity since only a minor percentage of those in the highest class give rise to successful pregnancy. Previous studies highlighted the potentiality of the analysis of metabolites in human embryo culture media, useful for the selection of embryos for implantation. In the present study, we analyzed in blind 66 human embryo culture media at 5 days after in vitro fertilization with the aim of quantifying compounds released by cell metabolism that were not present as normal constituents of the human embryo growth media, including purines, pyrimidines, nitrite, and nitrate. Only some purines were detectable (hypoxanthine and uric acid) in the majority of samples, while nitrite and nitrate were always detectable. When matching biochemical results with morphological evaluation, it was found that low grade embryos (n = 12) had significantly higher levels of all the compounds of interest. Moreover, when matching biochemical results according to successful (n = 17) or unsuccessful (n = 25) pregnancy, it was found that human embryos from the latter group released higher concentrations of hypoxanthine, uric acid, nitrite, and nitrate in the culture media. Additionally, those embryos that developed into successful pregnancies were all associated with the birth of healthy newborns. These results, although carried out on a relatively low number of samples, indicate that the analysis of the aforementioned compounds in the culture media of human embryos is a potentially useful tool for the selection of embryos for implantation, possibly leading to an increase in the overall rate of ART.

Influence of hypoxanthine concentrations on capacitation, acrosome reaction and In vitro fertilization in Ram Spermatozoa

The aim of the study was to evaluate the effect of hypoxanthine concentrations and incubation time on motility, hyperactivity (HA) and acrosome reaction (AR) in ram sperm in vitro. Semen samples (n= 40) were collected using artificial vagina from 3 mature Barki rams. Freshly ejaculated spermatozoa were pooled and subjected to swim up technique in modified sperm Tyrode's albumin lactate pyruvate (S-TALP) medium supplemented with different concentrations of hypoxanthine (5, 10, 15, 20 mg/ml). Motility, hyperactivity percentage and acrosomal status were recorded at 0, 1, 2, 3 and 4 h post-incubation. They were examined for ability to fertilize oocyte in vitro. The results showed that hypoxanthine concentrations and incubation time for 2 h did not significantly affect the motility. However, increase in incubation time for >2 h significantly (P<0.05) decreased the motility of spermatozoa as compared to control. Treatment of spermatozoa with 20 mg/ml hypoxanthine significant (P<0.05) increased in HA after 2 h of incubation compared to control (5.2±0.3 vs. 1.0± 0.1%). Significant (P<0.05) increase in total AR was associated to the increase in concentration of hypoxanthine with maximum at 20 mg/ml at 3h of incubation (82.0±2.2%). The fertilization rate of oocytes treated with 20 mg/ml hypoxanthine was higher as compared with control (42.8 vs. 26.0%). In conclusion, treatment of ram spermatozoa with 20 mg/ml hypoxanthine for 2 to 3 h was considered the best concentration for in vitro fertilization in sheep.

Purine and lipid metabolism in rats with a rotenone model of Parkinson’s disease under the influence of methanindiazenone

This study aims to evaluate the effect of methanindiazenone (МD), a new benzodiazepine derivative, on the levels of purine metabolites and lipids in the blood plasma of rats with rotenone (ROT) induced Parkinson’s disease (PD). The concentrations of ATP, ADP, AMP, xanthine, hypoxanthine, phospholipids (PL), cholesterol (CHOL), cholesterol esters (ECHOL), free fatty acids (FFA), and triglycerides (TG) were quantified in plasma samples by thin-layer chromatography. Our data demonstrate that in rats with ROT-induced PD the AMP/ATP ratio in plasma increased by 2.5 times compared to the control, and this indicator returned to normal values under the influence of MD. ROT also increased the concentration of xanthine and hypoxanthine by 26.7% (Р &lt; 0.001) and 42.4% (Р &lt; 0.001), respectively, compared to the control. MD restored xanthine concentration to 86.7% of the control level and returned hypoxanthine concentration to normal values. Besides, ROT reduced the blood plasma concentrations of PL, CHOL, ECHOL, FFA, TG by 22%, (Р &lt; 0.001), 18% (Р &lt; 0.001), 25% (Р &lt; 0.001), 28% (Р &lt; 0.001), 33% (Р &lt; 0.001), respectively. Under the influence of MD, such indicators as the blood plasma concentration of PL, CHOL, FFA returned to control levels. Оur results suggest that MD improves the metabolism of both purines and lipids in rats with ROT-induced PD.