Toxicological Factors Research Articles

Thermo sensitive and pH responsive surface modulated transdermal green tea nanogel: Structural, physiochemical and in vitro safety investigations

An altered simplistic biomimetic whole green tea extract-loaded nanogel (GE-C-NGL) was fabricated possessing pH-responsive and temperature-dependent intracellular transdermal nanotherapy. A biocompatible chitosan nanogel subsequently surface modified with oleic acid aiding Pluronic 127 discharging green tea extract on transdermal delivery was evaluated in light of structural, physiochemical, thermal, and in vitro toxicological factors by optical class, index class and spectrophotometrically class, and in vitro cell line toxicological evaluations, which precisely elaborated the nanosize particle size range and significant drug entrapment suggesting a spherical and thermo stable nanogel system. Additionally, sustained drug release configuration is displayed in mildly acidic conditions (pH 6) signifying ultra-pH sensitivity of GE-C-NGL. Moreover, strong mucin binding ability, pH-dependent swelling efficiency, negligible hemolytic ratio, and high antioxidant activity were obtained for enhanced transdermal efficacy. The comprehensive augmented polymeric blend transdermal nanogel, in light of the above preclinical biological and toxicological evaluations, evidently targets transdermal potential with promising bacterial biodegradable nanodrug therapy in clinical platforms.

The Role of Enzymatic Molecular Autopsy for Law Enforcement in Cyanide Poisoning Cases in Rabat, Morocco

Introduction: Cyanide poisoning is a serious public health problem throughout the world, including in Morocco. Enzymatic molecular autopsy offers a powerful method for detecting and quantifying cyanide levels in body tissue, which can assist law enforcement in poisoning cases. Methods: This observational study was conducted on 112 research subjects who died from cyanide poisoning in Rabat, Morocco. An enzymatic molecular autopsy was performed to measure cyanide levels in the blood, liver, and brain. Data were analyzed to determine the relationship between cyanide levels and demographic, clinical, and toxicological factors. Results: The highest levels of cyanide are found in the blood, followed by the liver and brain. There is a significant relationship between cyanide levels and causes of death, with cyanide levels highest in suicides and homicides. Conclusion: Enzymatic molecular autopsy should be considered as a routine method in the investigation of cyanide poisoning cases. This can help law enforcement to achieve justice for victims and their families.

Alcohol and toxicological factors influencing fatal falls from height in the Greater Tokyo Area: a retrospective study.

Falls from height pose a significant public health concern in urban regions, including the highly urbanized Greater Tokyo Area. The Japanese population is characterized by high rates of suicide and psychoactive drug usage, underscoring the importance of investigating these attributes in falls from height. This study aimed to retrospectively analyze the alcohol and toxicological aspects influencing falls from height in the Greater Tokyo Area between 2014 and 2022 and compare the findings with existing reports on other populations. In total, 75 cases of falls from height and 159 cases of natural deaths were included. Consistent with previous findings, Fisher's exact test revealed a predominance of males (66.67%, 50/75) and young adults (57.33%, 43/75) in falls from height. Multivariate logistic regression analysis identified antidepressant usage as the most significant risk factor within the target population, while younger individuals under alcohol influence constituted another high-risk group. Notably, contradictory to other populations, female individuals involved in fatal falls in the Greater Tokyo Area exhibited a higher frequency of alcohol consumption than males (48.00%, 12/25 vs. 26.00%, 13/50), and most of them were associated with suicide (83.33%, 10/12). These findings elucidate the population characteristics that pose a high risk for fatal falls from height in Japan and can serve as a reference for other Asian populations residing in similar megacities.

Influence of pollution on fish reproduction in the southern waters of Lake Ladoga

The southern waters of Lake Ladoga have important fishery significance - as a place for spawning, feeding and fishing. The hydrological features of this water area, combined with the location of sources of pollution, contributed to the creation of an increased level of anthropogenic load - massive toxicosis of fish and disruption of the process of natural reproduction, which was noted in the eighties of the last century. The period of early ontogenesis of fish is the most sensitive in the life cycle of fish, and this especially affects salmon and whitefish, which are especially sensitive to anthropogenic impacts, including toxicological factors. As studies have shown, the impact of pollutants has also had a negative impact on other fish species whose spawning grounds are located in this water area. Recent ichthyopathological studies of fish in this water area, which includes three bays: Shlisselburgskaya, Volkhovskaya and Svirskaya, showed massive damage to fish by toxicosis, which prompted a study of early juvenile fish in the littoral areas of the bays. It was shown that in the surveyed water areas from 30 to 70% of early juveniles (larvae, fry) are affected by toxicosis with visual manifestations of the pathological process in the bone tissue, visual, circulatory system, etc. Typical anomalies are craniofacial defects, spinal anomalies, eye defects, of cardio-vascular system. It has been shown that the bone, circulatory, and visual systems are very sensitive to the effects of toxicants in the early stages. Population reproduction is an integral expression of the influence of the combined action of environmental factors and the fish organism itself. The results of the studies showed a pronounced disruption of the natural reproduction of fish, which negatively affects the productivity of the reservoir. Preventive measures for fish reproduction are associated with the reclamation of polluted spawning grounds and factory reproduction of valuable fish species. Typical anomalies are craniofacial defects, spinal anomalies, eye defects, and cardiovascular system defects. It has been shown that the bone, circulatory, and visual systems are very sensitive to the effects of toxicants in the early stages. Population reproduction is an integral expression of the influence of the combined action of environmental factors and the fish organism itself.

A Brief Discussion of Multi-Component Organic Solids: Key Emphasis on Co-Crystallization

Co-crystallization (CCs) is a less studied phenomenon related to its applicability and reliability as it is directly related to the generation of newer multicomponent solids like co-crystals (CS), eutectic, salts or solid solutions etc. having improved physicochemical properties compared to their pure components. Further, the design and structural aspects of these multicomponent systems remain hindered compared to other techniques such as nanotechnology or solid dispersion. CC is a newer technique to modify the physicochemical as well as pharmaceutical characteristics of various drugs having issues like solubility, stability, etc. without altering or hindering their pharmacological activities. For drug delivery purpose, CC process has numerous advantages over nanotechnology and solid dispersion drug delivery techniques. CCs can modify the physicochemical properties of active pharmaceutical ingredients (API) have issues like sensitivity toward environmental hazards like temperature, moisture, or photostability issues. The availability of large numbers of conformers makes this technique favorable for the researchers in designing CS of newer and older. Although, solid dispersion and nanotechnology techniques are being utilized to a larger extent still there are some drawbacks of these techniques like stability, toxicological factors and protection from environmental factors need to be considered, while the CCs process drastically modifies the various pharmaceutical parameters without altering the pharmacological properties of API's. Salts, design of CS, their methods of preparation, and their application in various fields with special emphasis on their applicability in the pharmaceutical industry.

Anti-Diabetic Effects of Allium hookeri Extracts Prepared by Different Methods in Type 2 C57BL/J-db/db Mice

This study was conducted to evaluate whether Allium hookeri can control diabetic symptoms. Aqueous extract (AE1: 100 mg/kg BW, AE2: 200 mg/kg BW) and ethanol extract (EE1: 100 mg/kg BW, EE2: 200 mg/kg BW) of A. hookeri were orally administrated to diabetic mice (C57BL/J-db/db) for 8 weeks. The negative (NC) and the positive (PC) control groups were treated with 0.9% saline and metformin (150 mg/kg BW), respectively. Glucose and lipid profile (triglyceride, total cholesterol (TC), LDL-C, and HDL-C) as biochemical parameters, toxicological factors such as liver/kidney functional parameters (ALT, AST, BUN, and Cr), and NK cell activity in blood were measured. Oral glucose tolerance test (OGTT) and histopathological examination were also conducted. Compared with the NC group, AE and EE decreased blood glucose, HbA1c, area under the curve (AUC) during OGTT, and leptin levels while increasing adiponectin levels. Serum lipid profiles and toxicological factors levels were reduced by the A. hookeri extract. Interestingly, HDL-C, glomerular mesangial expansion score in the kidney, and NK cell activity were effectively controlled in EE groups. Based on the results, EE is considered to be more effective in reducing high blood glucose, lipid profile, and related factor levels than AE, and is comparable to metformin in some biomarkers. It can be presumed that EE can more effectively control the major anomalies in the diabetic model than AE, and it may be used to prevent diabetic symptoms without toxicity in the Type 2 diabetic model.

Pharmacological Properties of Ginsenoside Re.

Ginsenoside Re is a protopanaxatriol-type saponin extracted from the berry, leaf, stem, flower bud, and root of Panax ginseng. In recent years, ginsenoside Re (Re) has been attracting attention as a dietary phytochemical. In this review, studies on Re were compiled by searching a combination of keywords, namely “pharmacology,” “pharmacokinetics,” and “toxicology,” in the Google Scholar, NCBI, PubMed, and Web of Science databases. The aim of this review was to provide an exhaustive overview of the pharmacological activities, pharmacokinetics, and toxicity of Re, focusing on clinical evidence that has shown effectiveness in specific diseases, such as diabetes mellitus, nervous system diseases, inflammation, cardiovascular disease, and cancer. Re is also known to eliminate virus, enhance the immune response, improve osteoporosis, improve skin barrier function, enhance intracellular anti-oxidant actions, regulate cholesterol metabolism, alleviate allergic responses, increase sperm motility, reduce erectile dysfunction, promote cyclic growth of hair follicles, and reduce gastrointestinal motility dysfunction. Furthermore, this review provides data on pharmacokinetic parameters and toxicological factors to examine the safety profile of Re. Such data will provide a theoretical basis and reference for Re-related studies and future applications.

Identify the toxicological factors of a food poisoning caused by ingestion of Datura stramonium L. using liquid chromatography-tandem mass spectrometry

Identify the toxicological factors of a food poisoning caused by ingestion of Datura stramonium L. using liquid chromatography-tandem mass spectrometry

Machine learning models based on molecular descriptors to predict human and environmental toxicological factors in continental freshwater

Machine learning models based on molecular descriptors to predict human and environmental toxicological factors in continental freshwater

Predicting characterization factors of chemical substances from a set of molecular descriptors based on machine learning algorithms

A recommendation of: Rémi Servien, Eric Latrille, Dominique Patureau, Arnaud Hélias Machine learning models based on molecular descriptors to predict human and environmental toxicological factors in continental freshwater https://doi.org/10.1101/2021.07.20.453034

A Comparative Study of Selected Drug Delivery Systems: Key Emphasis on Cocrystallization

:The low solubility of an active pharmaceutical ingredient particularly biopharmaceutics classification system (BCS) Class II drugs leads to a lower dissolution profile, which in result causes a reduction in the overall bioavailability of drugs. Numerous approaches like nanotechnology, solid dispersion technique, micronization techniques, etc were aimed by scientists in the past to resolve this issue, but still not enough to get the desired outcomes.:Key focus of this review is the study of the advantages and disadvantages of cocrystallization, nanotechnology and solid dispersions drug delivery techniques and the benefits of using cocrystallization techniques over the above-mentioned techniques.:Various parameters including pharmaceutical, pharmacological and toxicological effects related to these mentioned drug delivery systems have been compared. Their advantages and disadvantages have been elaborated.:For drug delivery purpose, the cocrystallization process has numerous advantages over nanotechnology and solid dispersions drug delivery techniques discussed in the text. Cocrystallization is a newer technique that can modify the physicochemical and pharmaceutical properties of active pharmaceutical ingredients (API) with low solubility, low stability or sensitivity toward environmental hazards like temperature, moisture or photostability issues. During cocrystallization, the drug and the coformer interact with each other non-covalently in a fixed stoichiometric ratio. The availability of a large number of coformers makes this technique to be favorable for the researchers in designing cocrystals of newer and older API’s.:Although solid dispersions and nanotechnology techniques are being utilized to a larger extent, still there are some drawbacks of these techniques like stability, toxicological factors and protection from environmental factors that need to be considered, while the cocrystallization process drastically modifies the various pharmaceutical parameters without altering the pharmacological properties of API’s. Here in this review, we performed a comparative analysis between nanotechnology, solid dispersion and cocrystallization techniques along with the importance of cocrystallization in the modification of drug profile and various applications in the pharmaceutical and allied industry.

Chronic nitrate exposure cause alteration of blood physiological parameters, redox status and apoptosis of juvenile turbot (Scophthalmus maximus)

Nitrate (NO3−) is one of the common inorganic nitrogen compound pollutants in natural ecosystems, which may have serious risks for aquatic organisms. However, its toxicological mechanism remains unclear. In the current study, juvenile turbot (Scophthalmus maximus) were exposed to different concentrations of NO3− (CK− 3.57 ± 0.16, LN − 60.80 ± 1.21, MN − 203.13 ± 10.97 and HN − 414.16 ± 15.22 mg/L NO3–N) for 60 d. The blood biochemical assays results revealed that elevated NO3− exposure significantly increased the concentrations of plasma NO3−, NO2−, MetHb, K+, cortisol, glucose, triglyceride, lactate, while significantly decreased the concentrations of plasma Hb, Na+ and Cl−, which meant that NO3− caused hypoxic stress and further affected the osmoregulation and metabolism in fish. Besides, exposure to MN and HN induced a significant decrease in the level of antioxidants, including SOD (Point: 60th day, MN, HN v.s. CK: 258.36, 203.73 v.s. 326.95 U/mL), CAT (1.97, 1.17 v.s. 2.37 U/mL), GSH (25.38, 20.74 v.s. 37.00 μmol/L), and GPx (85.32, 71.46 v.s. 129.36 U/mL), and a significant increase of MDA (7.54, 9.73 v.s. 5.27 nmol/L), suggesting that NO3− exposure leading to a disruption of the redox status in fish. Also, further research revealed that NO3− exposure altered the mRNA levels of p53 (HN: up to 4.28 folds) and p53-regulated downstream genes such as Bcl-2 (inferior to 0.44 folds), caspase-3 (up to 2.90 folds) and caspase-7 (up to 3.49 folds), indicating that NO3− exposure induced abnormal apoptosis in the fish gills. Moreover, IBRv2 analysis showed that the toxicity of NO3− exposure to turbot was dose-dependent, and the toxicity peaked on the 15th day. In short, NO3− is an environmental toxicological factor that cannot be ignored, because its toxic effects are long-term and could cause irreversible damage to fish. These results would be beneficial to improve our understanding of the toxicity mechanism of NO3− to fish, which provides baseline evidence for the risk assessment of environmental NO3− in aquatic ecosystems.

Dose‐response relationships in health risk assessment of nutritional and toxicological factors in foods: development and application of novel biostatistical methods

Dose‐response relationships in health risk assessment of nutritional and toxicological factors in foods: development and application of novel biostatistical methods

Risk factors of tubal infertility in a tertiary hospital in a low-resource setting: a case-control study

BackgroundInfertility is the inability to sustain a pregnancy in a woman with regular (2–3 times per week) unprotected sexual intercourse for a period of 1 year. This is a major public health problem that remains under-recognised in Cameroon and most countries in sub-Saharan Africa. This study aimed at identifying the risk factors associated with tubal infertility in a tertiary hospital in Douala, Cameroon.MethodsWe conducted a case-control study at the Obstetrics, Gynaecology and Radiology Departments of the Douala Referral Hospital from October 1, 2016, to July 30, 2017. We recruited 77 women with tubal infertility diagnosed using hysterosalpingography and 154 unmatched pregnant women served as controls. Data on socio-demographic, reproductive and sexual health, and radiologic assessments were collected using a pretested questionnaire. The data were analysed using the Statistical Package for the Social Sciences (SPSS) software version 24.0. Logistic regression models were fitted to identify demographic, reproductive health factors, surgical, medical and toxicological factors associated with tubal infertility. The adjusted odds ratios (AOR) and their 95% confidence interval were interpreted. Statistical significance set at p < 0.05.ResultsSixty-one per cent of respondents had secondary infertility. Following multivariate logistic regression analysis, respondents who were housewives (AOR 10.7; 95% CI: 1.68–8.41, p = 0.012), self-employed (AOR 17.1; 95% CI: 2.52–115.8, p = 0.004), with a history of Chlamydia trachomatis infection (AOR 17.1; 95% CI: 3.4–85.5, p = 0.001), with Mycoplasma infection (AOR 5.1; 95% CI: 1.19–22.02, p = 0.03), with ovarian cyst (AOR 20.5; 95% CI: 2.5–168.7, p = 0.005), with uterine fibroid (AOR 62.4; 95% CI: 4.8–803.2, p = 0.002), have undergone pelvic surgery (AOR 2.3; 95% CI: 1.0–5.5, p = 0.05), have undergone other surgeries (AOR 49.8; 95% CI: 6.2–400, p = 0.000), diabetic patients (AOR 10.5; 95% CI 1.0–113.4, p = 0.05) and those with chronic pelvic pain (AOR 7.3; 95% CI: 3.2–17.1, p = 0.000) were significantly associated with tubal infertility while the young aged from 15 to 25 (AOR 0.07; 95% CI: 0.01–0.67, 0.021), those in monogamous marriages (AOR 0.05; 95% CI: 0.003–1.02, p = 0.05), as well as those with a history of barrier contraceptive methods (condom) (AOR 0.17; 95% CI: 0.03–1.1, p = 0.06) were less likely to have tubal infertility.ConclusionThe following factors were independently associated with tubal infertility: being a housewife, self-employed, history of Chlamydia trachomatis, Mycoplasma infection, and uterine fibroid. Furthermore, a history of pelvic surgery and other surgeries, diabetes mellitus, and chronic pelvic pain were also associated with tubal infertility. Young age, persons in monogamous marriages and users of barrier methods of contraception (condom) were less likely to have tubal infertility. Identification of these factors will be a target of intervention to avoid tubal infertility.

Relative potency factor approach enables the use of in vitro information for estimation of human effect factors for nanoparticle toxicity in life-cycle impact assessment

The major theme of the NRC report “Toxicity Testing in the Twenty-first Century” is to replace animal testing by using alternative in vitro methods. Therefore, it can be expected that in the future in vivo data will be replaced with in vitro data. Hence, there is a need for new strategies to make use of the increasing amount of in vitro data when developing human toxicological effect factors (HEF) to characterize the impact category of human toxicity in life cycle assessment (LCA). Here, we present a new approach for deriving HEF for manufactured nanomaterials (MNMs) based on the combined use of in vitro toxicity data and a relative potency factor (RPF) approach. In vitro toxicity tests with nano-CuO, nano-Ag and nano-ZnO and their corresponding ions were performed on THP-1, CaCo-2 and Hep-G2 cell lines. The ratio of the here calculated EC50 of the ionic form and the nanoform corresponds to the Relative Potency Factor (RPF). Using this approach, HEFs (case/kgintake) for the aforementioned nanoparticles were obtained. Non-carcinogenic HEFs (case/kgintake) for exposure via ingestion of 5.9E-01, 7.5E-03 and 2.5 E-02 were calculated for nano-Ag, nano-CuO and nano-ZnO, respectively. The HEF values here proposed were compared with HEF values extrapolated from in vivo toxicity data reported in the literature. The here presented procedure is the most appropriate approximation currently available for using in vitro toxicity data on MNM for application in the field of LCIA.

ВОСПРОИЗВОДСТВО РЫБ И БЕСПОЗВОНОЧНЫХ ПРИ ВОЗДЕЙСТВИИ ЗАГРЯЗНЯЮЩИХ ВЕЩЕСТВ

The pollution of surface waters has be-come rampant, which has led to the degrada-tion of many fishery reservoirs. The variety of toxicants entering water bodies in various ways is extremely large and is constantly being replenished with new substances. Their impact on aquatic organisms is associ-ated with the development of pathological processes, degradation of populations up to their death. This is especially evident in the main object of the use and protection of fish-ery reservoirs - fish. First of all, the most valuable species of whitefishes and salmon-ids suffered in the North-West region. The paper considers one of the main problems of fisheries in the North-Western region of Russia – the decrease in fish stocks and catches in natural reservoirs, and reveals the main reason for this ongoing process - the violation of natural and factory reproduction of fish and invertebrates due to the influence of a toxicological factor. This primarily affected the most valuable fish species - salmonids, white-fishes, pike perch. It has been shown that in recent years in Lake Ladoga (especially in its southern shallow zone, the main breeding and feeding zone of many fish species) and other reservoirs of the region, the negative situation of violation of repro-duction of fish and invertebrates (fish food supply) has significantly worsened, which has had a very negative impact, including the decline in the catch of especially valuable fish resources. Measures to prevent negative events are in-dicated. The need to take urgent measures to reduce the flow of pollutants into Europe's largest Lake Ladoga and other important fisheries reservoirs in the North-West region is emphasized.

Morphometric, Densitometric, and Mechanical Properties of Maxillary Teeth in 5-Month-Old Polish Merino Sheep

This study was performed to determine morphological, densitometric, mechanical, and elemental characteristics of maxillary teeth in 5-month-old Polish Merino sheep. The total tooth volume (Tvol) was determined using quantitative computed tomography. Micro-computed tomography was used to determine the total enamel volume (Evol), volumetric enamel mineral density, total dentine volume (Dvol), volumetric dentine mineral density, and total tooth enamel and dentine volume (EDvol). Compression testing was used to determine the ultimate force of teeth. Microhardness of enamel and dentine was evaluated using Vicker’s test. Elemental analysis of enamel and dentine was performed using a scanning electron microscopy technique. Tooth weight, length, Tvol, Evol, Dvol, and EDvol increased consequently from the lowest values for p², then for p³ and p⁴, to the highest values obtained for M¹ (all p < 0.05). Ultimate force reached the lowest value for p² compared with the other teeth (p < 0.05). The comparison of left and right teeth did not reveal significant differences for all the evaluated parameters (p > 0.05). Volumetric mineral density, calcium and phosphorus content, and microhardness were higher in enamel than in dentine, while the opposite results were obtained for magnesium and oxygen (all p < 0.05). Significantly higher enamel microhardness was found in mandibular i₁ compared with maxillary and mandibular premolars (p < 0.05). The elaborated experimental model of the determination of maxillary deciduous teeth traits may serve for further studies on the effects of physiological, pathological, environmental, nutritional, pharmacological, and toxicological factors affecting tooth development and mineralized tissue properties.

Physical, chemical, technological and toxicological characteristics of teiu potato flour (Jatropha elliptica (Pohl) Oken)

Jatropha elliptica (Pohl) Oken, popularly known as teiu potato, is widely used in folk medicine as a purgative and in the treatment of snake bites. There is no scientific data on the physicochemical characterization or anti-nutritional compounds, nor are there any reports on the application of this root in the production of flours for food purposes. Thus, the objective of this work was to contribute with new knowledge concerning the production yield of teiu potato root flour, characterize its physical, chemical and technological properties, and determine its anti-nutritional and toxicological factors. The flour was obtained on three repetitions (batches) and all analyses were carried out in triplicate for each repetition. The flour production yield was 34.29%, and the product obtained was an orange powder with a carbohydrate content of 77.55 g·100 g-1, high contents of total dietary fiber (22.8 g·100 g-1), protein (8.3 g·100 g-1) and ash (3.5 g·100 g-1), and a low lipid (0.8 g·100 g-1) content. The thermogram of the flour showed three endothermic peaks: temperature of gelatinization of the flour starch (77.42 °C); glass transition (106.55 °C) and protein and lipid-amylose complexes (131.77 °C). The flour presented antioxidant potential (89.59% of DPPH discoloration), a high concentration of phenolic compounds (12.67 mg eq gallic acid·100 g-1), nitrates (4.4 g·Kg-1), tannins (5.4 g tannic acid·100 g-1) and trypsin inhibitors (4.3 UTI·mg-1). The teiu potato flour requiring further, more profound studies before being indicated for human nutrition, due to the presence of anti-nutritional factors and the toxicity presented in the test with Artemia salina.

Antioxidant Activities of Quercetin and Its Complexes for Medicinal Application.

Quercetin is a bioactive compound that is widely used in botanical medicine and traditional Chinese medicine due to its potent antioxidant activity. In recent years, antioxidant activities of quercetin have been studied extensively, including its effects on glutathione (GSH), enzymatic activity, signal transduction pathways, and reactive oxygen species (ROS) caused by environmental and toxicological factors. Chemical studies on quercetin have mainly focused on the antioxidant activity of its metal ion complexes and complex ions. In this review, we highlight the recent advances in the antioxidant activities, chemical research, and medicinal application of quercetin.

Free amino acid concentration in serum and trapezius muscle from male and female silver foxes (Vulpes vulpes)

Serum and muscle concentrations of 29 amino acids were determined in Silver fox. Serum concentrations of proline, alanine, tyrosine and aromatic amino acids were significantly higher in males than in females (all P = 0.05). Taurine and glycine concentrations in skeletal muscles were significantly higher in males than in females (P &amp;lt; 0.01). Muscle concentrations of cysteic acid, taurine, aspartate, threonine, serine, glycine, alanine, citruline, valine, leucine, gamma-amino-butyrate, ethanoloamine, lysine and histidine were significantly higher than in serum in both sexes (P &amp;lt; 0.05). In females, the concentrations of glutamate, glutamine, cystathionine, isoleucine, tyrosine, phenylalanine, arginine and amino-adipic acid were significantly higher in muscles than in serum (P &amp;lt; 0.05). Tryptophan concentration was significantly higher in serum from males than in muscles (P = 0.01). The concentration of branched-chain amino acids in skeletal muscles was approximately two times higher than in serum in both groups of foxes (P ≤ 0.01). Similar differences were obtained for aromatic amino acids in females (P = 0.04). The elaborated experimental model may serve for further studies focused on amino acid metabolism regulation in Canide and other monogastric mammals, especially with the use of environmental, dietary, pharmacological and toxicological factors. The elaborated experimental model may be an attractive alternative to replace some experiments on dogs.