Levels In Muscle Tissue Research Articles

GlutaR: AHigh-Performance Fluorescent Protein-Based Sensor for Spatiotemporal Monitoring of Glutamine Dynamics In Vivo.

Glutamine is the most abundant amino acid in human blood and muscle, and is integral to a wide variety of functions in cancer cells. However, the inability to monitor the subcellular distribution of glutamine in real-time has obscured understanding of glutamine metabolism under physiological and pathological conditions. Here, we report the development of a genetically encoded fluorescent sensor and demonstrate how this GlnBP-cpYFP fusion "GlutaR sensor" undergoes glutamine-induced conformational changes reflected in detectable fluorescence responses. Obtained after iterative screening of approximately 1,600 variants, GlutaR exhibits a ratiometric readout, fast response kinetics, and high responsivity, and we demonstrate its selectivity for monitoring glutamine fluctuations in multiple cell types. Additionally, using digitonin permeabilization of GlutaR HeLa cells, we generated a calibration curve and performedin situtitration to quantify free glutamine concentrations in subcellular compartments (cytosol, nucleus, mitochondria). Subsequently, we applied GlutaR to investigate how chemical and genetic inhibition of GS and GLS differentially alter glutamine levels in subcellular compartments. Finally, we demonstrate GlutaR's ability to monitor dynamic glutamine levels in muscle and liver tissues of diabetic micein vivo.These findings collectively demonstrate GlutaR as a versatile tool for the spatiotemporal characterization of glutamine metabolism in living cells and tissues.

The muscle-intervertebral disc interaction mediated by L-BAIBA modulates extracellular matrix homeostasis and PANoptosis in nucleus pulposus cells.

Upon engaging in physical activity, skeletal muscle synthesizes myokines, which not only facilitate crosstalk with various organs, including the brain, adipose tissue, bone, liver, gut, pancreas, and skin but also promote intramuscular signaling. Crosstalk is vital for maintaining various physiological processes. However, the specific interactions between skeletal muscle and intervertebral discs remain largely unexplored. β-Aminoisobutyric acid (BAIBA), an exercise-induced myokine and a metabolite of branched-chain amino acids in skeletal muscle, has emerged as a key player in this context. Our study demonstrated that exercise significantly elevates BAIBA levels in skeletal muscle, plasma, and nucleus pulposus (NP) tissues. Moreover, exercise enhances extracellular matrix (ECM) synthesis in NP tissues and upregulates L-BAIBA synthase in skeletal muscle. Both in vivo and in vitro evidence revealed that L-BAIBA impedes PANoptosis and ECM degradation in NP cells by activating the AMPK/NF-κB signaling pathway. These findings suggest that exercise, coupled with the resulting increase in L-BAIBA, may serve as an effective intervention to decelerate the progression of intervertebral disc degeneration (IDD). Consequently, L-BAIBA, which originates from skeletal muscle, is a promising new therapeutic approach for IDD.

The modulatory effects of Lonicera caerulea L. extract and omega-3 on sarcopenia via regulating PI3K and FOXO signaling pathways in rats

Introduction: Sarcopenia is an inflammatory disease caused by a disruption of muscle homeostasis. Lonicera caerulea L. (Haskap berry) (HB) extract and omega-3 (ω−3) possess antioxidant and anti-inflammatory activities. This study assesses the potential ameliorating effects of HB extract and ω−3 supplementation on dexamethasone (DEXA)-induced sarcopenia. Methods: Rats were divided into five groups; the negative control group was injected with saline (i.p.); groups 2, 3, 4, and 5 were injected with DEXA (2 mg/kg/d, i.p.); groups 3 and 4 also received 400 mg/kg/d and 100 mg/kg/d of HB extract and ω−3, respectively, while group 5 received both treatments daily for 21 days. The ameliorative effects of treatments were investigated by measuring lysosomal proteolytic enzyme cathepsin activity, phosphatidylinositol 3 kinase (PI3K) activity, nuclear factor kappa beta (NF-κB) level, and heme oxygenase-1 (HO-1) activity. The gene expression levels of muscle ring-finger protein (MuRF) and forkhead box O (FOXO) transcription factor were also evaluated. Biochemical and histological examinations were done on muscle tissues. Results: DEXA caused a significant elevation (P<0.05) in NF-κβ level and cathepsin activity in muscle tissue. Also, it significantly upregulated the muscle atrophy markers. Meanwhile, PI3K and HO-1 activities were significantly reduced. HB extract and ω−3 administration significantly (P≤0.05) reversed these effects and downregulated the mRNA expression levels of MuRF and FOXO. Also, the histopathological examination confirmed these results. Conclusion: The current study proved the ameliorative effects of HB extract and ω−3 on sarcopenia parameters. Therefore, they might be potential therapeutic agents for myopathy/sarcopenia.

Effect of L-Citrulline on Creatine Kinase MM (CK-MM) Isoenzymes in Mice: An In Vivo Study Focusing on Immunohistochemistry Analysis

Highlights:1. This study elucidates the effect of L-citrulline supplementation on creatine kinase MM (CK-MM) expression post-eccentric exercise, offering novel insights into its potential role in mitigating muscle damage.2. The findings demonstrate that L-citrulline administration significantly reduces CK-MM expression levels in skeletal muscle tissue, suggesting its therapeutic potential in enhancing muscle recovery and performance following exercise-induced damage.3. This study contributes valuable insights into the multifaceted benefits of L-citrulline supplementation for supporting overall muscle health and performance by identifying its protective effects under different mechanisms, including improved blood flow, antioxidant activity, enhanced mitochondrial function, and promotion of muscle protein synthesis. Abstract Eccentric exercise often induces muscle injuries in athletes, resulting in impaired performance and prolonged recovery time. Creatine kinase MM (CK-MM) is a biomarker for assessing muscle damage, with elevated levels indicating injury. L-citrulline, an amino acid, has shown promise in enhancing performance and reducing recovery time. However, its specific effect on CK-MM remains unclear. This study utilized immunohistochemistry analysis to investigate the effect of L-citrulline supplementation on CK-MM expression post-eccentric exercise in male BALB/c mice. This in vivo study was conducted with a post-test-only design. A total of 25 mice were divided into two control groups (normal/C1 and negative/C2) and three treatment groups (T1, T2, and T3), each containing five mice. The T1, T2, and T3 groups were daily administered 250, 500, and 1,000 mg/kg bw of L-citrulline for seven days, respectively. All mice, except the C1 group, performed a downhill running procedure. The CK-MM expression in skeletal muscle tissue post-eccentric exercise was assessed using immunohistochemistry analysis. The statistical analysis included the Shapiro-Wilk test for data distribution and the Kruskal-Wallis and Mann-Whitney post-hoc tests for significant differences (p<0.05). The results showed that CK-MM expression in the C2 group (91.00±2.24%) was significantly higher (p=0.008) than that of the C1 group (70.00±10.0%). Subsequently, the T1 (68.00±9.08%, p=0.008), T2 (72.00±7.58%, p=0.008), and T3 (67.00±9.75%, p=0.008) groups exhibited significantly lower expressions than the C2 group. These results were consistent with the role of CK-MM as a marker for muscle damage, and they indicated that L-citrulline might have a protective effect against muscle damage post-eccentric exercise. However, no significant differences were observed among the C1, T1, T2, and T3 groups. In conclusion, L-citrulline supplementation demonstrates promise in attenuating muscle damage following eccentric exercise, as evidenced by reduced CK-MM expression levels. These findings highlight the potential therapeutic role of L-citrulline in enhancing muscle recovery and performance.

Hydrogen attenuates ischaemia–reperfusion injury in skeletal muscles post-limb replantation by activating the NRF2/HO-1 signalling pathway to reduce BAX expression

BackgroundIschaemia–reperfusion injury (IRI) is a critical complication post-limb replantation. The oxidative stress and cellular apoptosis due to IRI considerably hinder the healing process. This study aimed to investigate the modulatory effects of pre-perfusion with hydrogen-rich heparin sodium on the nuclear factor erythroid 2–related factor 2 (NRF2)/haeme oxygenase-1 (HO-1) pathway and its potential mechanisms in mitigating skeletal muscle IRI post-limb replantation. MethodsForty healthy Sprague–Dawley rats (250–300 g) were classified into five groups (n = 8 each): normal control, IRI + heparin sodium pre-perfusion (heparin group), IRI + hydrogen-rich heparin sodium pre-perfusion (hydrogen-rich heparin group), IRI + hydrogen-rich heparin sodium pre-perfusion + NRF2 inhibitor (hydrogen-rich heparin + all-trans retinoic acid [ATRA] group), and IRI + heparin sodium pre-perfusion + NRF2 inhibitor (heparin + ATRA group). The activation of the NRF2/HO-1 pathway in skeletal muscle IRI was evaluated based on HO-1 expression using western blotting and immunofluorescence. Furthermore, haematoxylin and eosin staining and transmission electron microscopy were employed to determine the histopathological characteristics. Additionally, superoxide dismutase and malondialdehyde levels in skeletal muscle tissue were measured to assess antioxidant capacity and the degree of oxidative stress damage. Tissue hypoxia was assessed based on hypoxia-inducible factor 1-alpha expression, whereas apoptosis markers BCL-2-associated X protein (BAX) and Caspase-3 in skeletal muscle tissues were analysed using western blotting with terminal deoxynucleotidyl transferase dUTP nick end labelling staining to quantify cell apoptosis. ResultsCompared with the control group, the heparin group exhibited significant pathological changes, including inflammatory infiltration and cellular hypertrophy, with increased apoptosis and oxidative stress. Notably, NRF2 suppression aggravated these effects. However, hydrogen-rich heparin sodium prominently activated the NRF2/HO-1 pathway, enhancing antioxidant defence and reducing BAX/Caspase-3-mediated apoptosis, thereby mitigating IRI-induced damage. The use of an NRF2 inhibitor to inhibit NRF2 excitation by hydrogen-rich heparin sodium notably weakened NRF2 activation and the antioxidant response, resulting in a substantial increase in cellular apoptosis. ConclusionPre-perfusion with hydrogen-rich heparin sodium markedly diminishes the BAX/Caspase-3-mediated apoptotic pathway in skeletal muscle tissues with IRI through the excitation of the NRF2/HO-1 pathway.

Comparative analysis of Scarb1 and Cd36 in grass carp (Ctenopharyngodon idellus): Implications for DHA uptake

The polyunsaturated fatty acid docosahexaenoic acid (DHA) significantly influences fish growth and lipid metabolism. Nevertheless, the specific mechanism by which DHA is transported and exerts its effects remains unclear. Scavenger receptor class B type I (SCARB1) is essential for maintaining cellular cholesterol levels and regulating the immune system in mammals, as well as facilitating the uptake of fatty acids (FAs). Another class B scavenger receptor, cluster-determinant 36 (CD36), is involved in promoting the uptake and transport of long-chain fatty acids. However, the molecular characteristics of the grass carp scarb1 gene have not yet been reported, and the potential role of Scarb1 and Cd36 in mediating DHA transport and metabolism remains uncertain. This study aimed to investigate the effects of Scarb1 and Cd36 on DHA transport. Initially, grass carp scarb1–1 and scarb1–2 were cloned. Predictions were made regarding their structural characteristics, including number and presence of transmembrane domains and glycosylation sites. Furthermore, gene structure analysis revealed that scarb1–1 has two additional exons in the 3′-region compared to scarb1–2. The multiple sequence alignment indicated that Scarb1 exhibits conserved motifs and amino acid residues across vertebrates. mRNA expression of scarb1–1 was the highest in the intestine, while scarb1–2 was highest expressed in adipose tissue, with both having lower expression levels in muscle tissue. Scarb1–1 was primarily localized on the cell membrane, whereas Scarb1–2 was found in both the cell membrane and cytoplasm. After overexpression of grass carp Scarb1–1, Scarb1–2, and Cd36 in HEK 293 T cells, DHA incubation showed that only Cd36 significantly increased cellular DHA relative content, suggesting a potential role of Cd36 in DHA transport. These findings will serve as a basis for further research on fatty acid transport in fish.

Bioaccumulation of metals in muscle tissues of economically important fish species from black sea Lagoon lakes in Türkiye: Consumer health risk and nutritional value assessment

This study is the first comprehensive investigation into the levels of potentially toxic elements (PTEs) in the muscle tissues of various fish species (Carassius gibelio, Squalis cephalus, Esox lucius, and Tinca tinca) in Lagoon Lakes Akgöl and Semenit (LLAS), Samsun, Türkiye. A multidisciplinary approach was employed, integrating elemental analysis, health risk assessment, and source identification techniques to evaluate the distribution, sources, and health risks of PTE contamination in fish. The mean concentrations of toxic and trace elements (µg/kg) were determined in ascending order: Cd (5) < Co (8) < Cr (18) = Pb (18) < Ni (66) < As (163) < Cu (290) < Mn (798) < Fe (6150) < Zn (6250). In contrast, the concentrations of macro elements are provided in units of mg/kg, as follows: Mg (391) < Na (677) < Ca (1698) < P (2314) < K (3837), with notable variations across species. Health risk assessment methodologies indicated that PTE levels in fish muscle tissues generally fell below regulatory limits, indicating their safety for consumption. Noncarcinogenic risk assessment further documented the safety of consuming these fish species, with elevated maximum safe consumption quantity (MSCQ) values observed for all metals. In addition, the estimated daily intake of PTEs was found to be below reference doses, confirming the safety of consumption. Esox lucius demonstrated a highest abundance of essential nutrients (e.g., Ca, K, Mg, and P). Source identification techniques indicated that residential waste, lithogenic materials, and agricultural practices are significant contributors to PTE contamination. Overall, this research stresses the importance of monitoring PTE levels in fish, ensuring food safety and protect human health.

Using Stable Isotope Techniques to Analyze the Trophic Relationship between Argentine Hake (Merluccius hubbsi) and Anisakidae.

The Argentine hake (Merluccius hubbsi) is a vital fishery species in the Southwest Atlantic, recognized for its substantial economic importance. Previous studies have identified Anisakidae larvae as common parasites of M. hubbsi. However, the nutritional relationships between these parasites and their host remain poorly understood. This study employs stable isotope techniques to investigate the specific nutritional relationships between Anisakidae larvae and different tissues of M. hubbsi. The findings reveal notable differences in δ13C and δ15N compositions between the parasites and their host. The lower δ13C values in parasites compared to host tissues indicate the utilization of different carbon sources. The δ15N values of the parasites partially overlap with those of the host's stomach, indicating that the parasites primarily derive nutrients from the host's stomach. Nutritional niche indicators show that parasites have a broad carbon range (CR) and nitrogen range (NR), suggesting a high diversity in nutritional sources. The trophic discrimination factor (ΔTDF), which represents the difference in stable isotope values between host tissues and parasites, was analyzed for both δ13C and δ15N. The ΔTDFδ13C between the host liver and the parasites showed the greatest variation, indicating a strong dependence of the parasites on the liver's carbon sources. In contrast, variations in ΔTDFδ15N between host tissues and parasites were minimal. Analyzing ΔTDF across different stages of gonadal maturity in the host fish indicates that, as the gonads of the host fish mature, ΔTDFδ13C between host tissues and parasites significantly decreases (p < 0.01). The Kruskal-Wallis test showed significant differences in ΔTDFδ13C values among different parasite infection levels in muscle, liver, and stomach tissues, while no significant differences were found for ΔTDFδ15N values. These findings offer valuable insights into the nutritional relationships between parasites and hosts, aiding in a better understanding of the growth conditions and habitats of M. hubbsi.

ATP-binding cassette family C member 1 constrains metabolic responses to high-fat diet in male mice.

Glucocorticoids modulate glucose homeostasis, acting on metabolically active tissues such as liver, skeletal muscle, and adipose tissue. Intracellular regulation of glucocorticoid action in adipose tissue impacts metabolic responses to obesity. ATP-binding cassette family C member 1 (ABCC1) is a transmembrane glucocorticoid transporter known to limit the accumulation of exogenously administered corticosterone in adipose tissue. However, the role of ABCC1 in the regulation of endogenous glucocorticoid action and its impact on fuel metabolism has not been studied. Here, we investigate the impact of Abcc1 deficiency on glucocorticoid action and high-fat-diet (HFD)-induced obesity. In lean male mice, deficiency of Abcc1 increased endogenous corticosterone levels in skeletal muscle and adipose tissue but did not impact insulin sensitivity. In contrast, Abcc1-deficient male mice on HFD displayed impaired glucose and insulin tolerance, and fasting hyperinsulinaemia, without alterations in tissue corticosterone levels. Proteomics and bulk RNA sequencing revealed that Abcc1 deficiency amplified the transcriptional response to an obesogenic diet in adipose tissue but not in skeletal muscle. Moreover, Abcc1 deficiency impairs key signalling pathways related to glucose metabolism in both skeletal muscle and adipose tissue, in particular those related to OXPHOS machinery and Glut4. Together, our results highlight a role for ABCC1 in regulating glucose homeostasis, demonstrating diet-dependent effects that are not associated with altered tissue glucocorticoid concentrations.

Comparing Nitric Oxide Generation Pathways using Dietary L-Arginine and Dietary Nitrate: A 15N tracer study in Wistar Rats

Mammals generate nitric oxide (NO) through two main pathways. In the direct production pathway, endogenous nitric oxide synthase (NOS) enzymes catalyze the reaction of L-arginine with oxygen, producing nitric oxide and citrulline. When oxygen accessibility is low, the reductive pathway supplies nitric oxide through the nitrate-nitrite-NO reduction cascade. Additional research is needed to understand whether the two NO generation pathways interact and what effects the two pathways have on the body and each other. We investigated how dietary supplementation of 15N-L-arginine (0.5 g/kg), 15N-nitrate (0.013 g/kg), or a combination of L-arginine and nitrate influences nitrate concentrations in plasma, skeletal muscle, and liver tissue from Wistar rats. We administered treatments via oral gavage. Two hours after treatment administration, we euthanized the rats and collected tissue samples. The nitrate concentrations were measured using chemiluminescence, and future mass spectrometry analysis for 15N/14N ratios will be performed. The calculated concentrations were compared between treatment groups using single factor analysis of variance. Firstly, we observed that nitrate administration significantly increased total nitrate levels in plasma, liver, and muscle tissues compared to the control group. Interestingly, L-arginine alone did not result in a significant rise in total nitrate concentrations. Notably, liver tissue from the L-arginine-treated group had slightly lower concentrations of nitrate than the control group. The combination of L-arginine and nitrate showed no statistically significant difference when compared with the nitrate-treated group in all three tissues. These results suggest that a bolus of L-arginine does not have a substantial short-term effect (within 2 hours after ingestion) on total nitrate concentrations in rat tissues. Future mass spectrometry analysis will indicate how the tissues handle acute ingestion of two different NO sources: L-arginine and nitrate. Further research must be performed for a more detailed understanding of the kinetics of arginine and nitrate, as well as for the effects of these dietary supplements on improving NO homeostasis. This work was supported by intramural NIDDK/NIH grant ZIA DK 025104-15 to Alan N. Schechter. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

The Role of p38 Mitogen-Activated Protein Kinase-Mediated F-Actin in the Acupuncture-Induced Mitigation of Inflammatory Pain in Arthritic Rats.

The analgesic efficacy of acupuncture has been widely recognized. However, the mechanism by which manual acupuncture-generated mechanical stimuli translate into biological signals remains unclear. This study employed a CFA-induced inflammatory pain rat model. Acupuncture intervention was then performed following standardized procedures. Enzyme-linked immunosorbent assay (ELISA) assessed inflammatory cytokines levels, while immunofluorescence and qRT-PCR screened the level of p38 and F-actin expression in the ST36 acupoint area of rats. Results indicated increased inflammatory factors, including IL-1β and TNFα, with reduced paw withdrawal mechanical threshold (PWMT) and paw withdrawal thermal latency (PWTL) in CFA rats compared to unmodeled rats. After acupuncture intervention, the heightened expression level of F-actin and p38 mRNA and the phosphorylation of p38 in the acupoint area was observed alongside decreased inflammatory factors in diseased ankle joints. The application of lifting and thrusting manipulations further enhanced the effect of acupuncture, in which the molecular expression level of muscle and connective tissue increased most significantly, indicating that these two tissues play a major role in the transformation of acupuncture stimulation. Moreover, antagonizing p38 expression hindered acupuncture efficacy, supporting the hypothesis that p38 MAPK-mediated F-actin transduces mechanical signals generated by acupuncture and related manipulation into biological signals.

High temperature ameliorates high-fat diet-induced obesity by promoting ceramide breakdown in skeletal muscle tissue

Abstract Obesity is considered an epidemic often accompanied by insulin resistance (IR). Heat treatment (HT) has been shown to prevent high-fat diet-induced IR in skeletal muscle, but the underlying mechanisms are poorly understood. In this study, we discovered that high temperature alleviated the hallmarks of obesity by promoting glycogen synthesis and lowering blood glucose levels in skeletal muscle tissue (SMT). Additionally, HT maintained the decay phase of heat shock factor 1 (HSF1), leading to the activation of gene expression of heat shock proteins (HSPs), which contributed to the alleviation of IR in SMT of diet-induced obese (DIO) mice. Metabolomics and lipidomics analyses showed that HT promoted ceramide (Cer) breakdown, resulting in an elevation of both sphingomyelin (SM) and sphingosine, which further contributed to the amelioration of IR in SMT of DIO mice. Importantly, the increase in sphingosine was attributed to the heightened expression of the acid ceramidase N-acylsphingosine amidohydrolase 1 (ASAH1), and the inhibition of ASAH1 attenuated HT-relieved IR in SMT of DIO mice. Surprisingly, high temperature increased the composition of Cer and cholesteryl ester in lipid droplets of skeletal muscle cells. This not only helped alleviate IR but also prevented lipotoxicity in SMT of DIO mice. These findings revealed a previously unknown connection between a high-temperature environment and sphingolipid metabolism in obesity, suggesting that high temperature can improve IR by promoting Cer catabolism in SMT of obese mice.

Organoleptic, physico-chemical and microbiological parameters of broiler chicken meat in combined toxicosis

Increasing the productivity of animals and birds, resistance to non-infectious and infectious diseases remains a priority in agricultural production. Currently, the problem of obtaining environmentally friendly animal feed and food of animal origin is acute. The main natural and anthropogenic pollutants of feed and food raw materials are mycotoxins, toxic elements and pesticides. It is important to highlight the role of the influence of combinations of natural and anthropogenic pollutants on a living organism. Mycotoxins, toxic elements and pesticides, in addition to their polytoxic effect on animals, significantly reduce product quality indicators. This article examines the organoleptic, physicochemical and microbiological parameters of broiler chicken meat during the experimental introduction of natural (T-2 toxin and deoxynivalenol) and anthropogenic (cadmium and diquat) ecotoxicants against the background of the use of modified bentonite. Experiments were conducted on 40 broiler chickens divided into 4 groups: group 1 - biological control, received the basic diet, group 2 – toxic control (broiler chickens received food contaminated with mycotoxins, cadmium and diquat); group 3 – broiler chickens received toxic feed with a modified sorbent; group 4 – control due to the harmlessness, broiler chickens with a basic diet received a modified sorbent. The duration of the experiment was 21 days. When assessing the organoleptic parameters, it was revealed that the meat samples of broiler chickens of groups 1, 3 and 4 correspond to the characteristic features of fresh meat, groups 2 – of questionable freshness. When evaluating the physico-chemical parameters of chicken meat of the second group, a significantly increased value of the pH level of muscle tissue, an increase in amino-ammonia nitrogen by 34.9%, the amount of volatile fatty acids, acid and peroxide numbers by 1.9, 3.4 and 5.0 times, respectively, was recorded relative to other experimental groups. The qualitative reaction to peroxidase in testing 1, 3 and 4 samples of chicken meat was positive, in 2 – negative. The contamination with cocci and sticks of smears-prints of the surface layers of the muscles of broiler chickens of the second group was recorded. The organoleptic, physico-chemical and microbiological parameters of broiler chicken meat against the background of the use of a modified sorbent did not differ significantly from those of the biological control group and corresponded to the characteristic features of fresh meat.

Development of a Predictive Model for Iron Levels in Bovine Muscle Tissue Using Hair as a Predictor.

The assessment of iron levels in cattle muscle tissue is crucial for livestock management because it influences both animal health and meat quality, key factors in sustainable development. This study aimed to develop an optimal model for noninvasively predicting the iron content in Hereford cattle muscle tissue, contributing to a comprehensive understanding of the animals' elemental status. The research involved the atomic absorption analysis of muscle tissue and hair samples from cattle. A regression model was constructed using the least squares method to identify the most effective approach. These findings have ecological applications, aiding in evaluating environmental health and establishing acceptable iron thresholds for animals. The proposed mathematical model utilizing biomarkers (levels of Mg, K, Fe, Al, Cr in hair) will allow for the assessment of iron levels in cattle muscle tissue throughout the period of productive use, with the possibility of adjustment and tracking the changes in elemental status over time. The utilization of the developed method will enable the diagnosis of animal elementosis and assessment of the iron level burden. Subsequently, this will allow for the improvement of the qualitative characteristics of the final product. Thus, the obtained data contribute to fundamental knowledge regarding the content and variability of iron levels in the muscle tissue of cattle.

Monocarboxylate transporter 4 deficiency enhances high-intensity interval training-induced metabolic adaptations in skeletal muscle.

High-intensity exercise stimulates glycolysis, subsequently leading to elevated lactate production within skeletal muscle. While lactate produced within the muscle is predominantly released into the circulation via the monocarboxylate transporter 4 (MCT4), recent research underscores lactate's function as an intercellular and intertissue signalling molecule. However, its specific intracellular roles within muscle cells remains less defined. In this study, our objective was to elucidate the effects of increased intramuscular lactate accumulation on skeletal muscle adaptation to training. To achieve this, we developed MCT4 knockout mice and confirmed that a lack of MCT4 indeed results in pronounced lactate accumulation in skeletal muscle during high-intensity exercise. A key finding was the significant enhancement in endurance exercise capacity at high intensities when MCT4 deficiency was paired with high-intensity interval training (HIIT). Furthermore, metabolic adaptations supportive of this enhanced exercise capacity were evident with the combination of MCT4 deficiency and HIIT. Specifically, we observed a substantial uptick in the activity of glycolytic enzymes, notably hexokinase, glycogen phosphorylase and pyruvate kinase. The mitochondria also exhibited heightened pyruvate oxidation capabilities, as evidenced by an increase in oxygen consumption when pyruvate served as the substrate. This mitochondrial adaptation was further substantiated by elevated pyruvate dehydrogenase activity, increased activity of isocitrate dehydrogenase - the rate-limiting enzyme in the TCA cycle - and enhanced function of cytochrome c oxidase, pivotal to the electron transport chain. Our findings provide new insights into the physiological consequences of lactate accumulation in skeletal muscle during high-intensity exercises, deepening our grasp of the molecular intricacies underpinning exercise adaptation. KEY POINTS: We pioneered a unique line of monocarboxylate transporter 4 (MCT4) knockout mice specifically tailored to the ICR strain, an optimal background for high-intensity exercise studies. A deficiency in MCT4 exacerbates the accumulation of lactate in skeletal muscle during high-intensity exercise. Pairing MCT4 deficiency with high-intensity interval training (HIIT) results in a synergistic boost in high-intensity exercise capacity, observable both at the organismal level (via a treadmill running test) and at the muscle tissue level (through an ex vivo muscle contractile function test). Coordinating MCT4 deficiency with HIIT enhances both the glycolytic enzyme activities and mitochondrial capacity to oxidize pyruvate.

BIOMARKERS OF LIPID AND PROTEIN OXIDATION IN THE MUSCLE TISSUE OF RAINBOW TROUT (ONCORHYNCHUS MYKISS WALBAUM) TREATED IN VITRO WITH ROOT AND STEM EXTRACTS OF GREATER CELANDINE (CHELIDONIUM MAJUS L.)

The main aim of the present study was to evaluate the oxidative stress biomarkers [TBARS, carbonyl derivatives of oxidative modification of proteins (OMP), total antioxidant capacity (TAC)] in the muscle tissue of rainbow trout (Oncorhynchus mykiss Walbaum) after in vitro incubation with the root and stem extracts derived from greater celandine (Chelidonium majus L., CM) (at final concentrations of 5 and 2.5 mg/mL) collected in South Park in Słupsk in the Pomeranian Province (northern part of Poland). The current study demonstrated the increase in TBARS levels after in vitro incubation of rainbow trout muscle tissue with stem and root extracts of CM at a final concentration of 5 mg∙mL-1 compared to untreated control samples. There was a statistically significant increase in TBARS levels compared to controls. We obtained similar results after in vitro incubation with root and stem extracts of CM at a final concentration of 2.5 mg∙mL-1 with rainbow trout muscle tissue, where we also observed a statistically non-significant increase in TBARS levels. There was a decrease in the levels of aldehydic derivatives and ketonic derivatives of OMP in muscle tissue after incubation with extracts from roots and stems of CM at final concentrations of 5 mg∙mL-1 compared to untreated controls. There was a decrease in the levels of aldehydic and ketonic derivatives of OMP in muscle tissue after incubation with extracts from roots and stems of CM at final concentrations of 2.5 mg∙mL-1 compared to untreated controls. TAC levels in rainbow trout muscle tissue after in vitro incubation with extracts of CM roots and stems at final concentrations of 5 and 2.5 mg∙mL-1 were not statistically significantly increased. The present study investigated the antioxidant potential of CM. Extracts from CM roots and stems exert their activity by inhibiting protein damage.

Randomized trial of mechanotherapy for the treatment of stress urinary incontinence in women.

Stress urinary incontinence (SUI) presents as unintentional urine leakage associated with activities. It significantly affects quality of life (QoL) and is the most common type of incontinence in women. Current treatment options, particularly non-surgical therapies, are lacking. To assess the efficacy of mechanotherapy provided by the Flyte® intra-vaginal device during pelvic floor muscle training (PFMT). This was a randomized, controlled, double-blinded trial. Flyte is a repeat use device for conditioning and strengthening the pelvic floor muscles (PFMs). It provides two-part mechanotherapy. Part 1 is the stretching and preloading of the PFM from the internal wand. Part 2 integrates mechanical pulses which elicit muscle cellular and tissue level responses that trigger cellular regeneration, improve neuromuscular facilitation and motor learning. Subjects used the device for 5 min/day for 12 weeks. Subjects (144) were randomized and evaluated at 6 and 12 weeks. Arm A (72) received both Part 1 and Part 2 mechanotherapy for 12 weeks, whereas Arm B (72) received Part 1 therapy for 6 weeks, then crossed over to full therapy. Mean age was 50, 49, respectively, prior pelvic/abdominal surgery 26%, 46%, and previous incontinence treatments 13%, 22%. The primary endpoint was 24-h pad weight (24-HR PW) at 6 weeks. Secondary endpoints were 24-HR PW at 12 weeks and QoL [International Consultation on Incontinence Questionnaire (ICIQ), Urinary Incontinence Quality of Life (IQOL)]. Part 1 therapy had a greater than anticipated therapeutic effect. Thus, the study was underpowered to identify differences between study arms. Therefore, data were pooled to assess the effects of mechanotherapy. Twenty four-HR PW was significantly reduced at 6 weeks (p = <0.0001), with further reduction from 6 to 12 weeks (p = <0.0001). Data were stratified based on 24-HR PW severity. Significant reductions were noted in all severity groups (mild p = <0.0001, moderate p = <0.0001, severe p = <0.01). QoL was similarly improved at 6 weeks (ICIQ p = <0.0001, IQOL p = <0.0001), and 12 weeks (ICIQ p = <0.0001, IQOL p = <0.0001). Compliance was >80% at 6 weeks and 70% at 12 weeks. Two-part mechanotherapy significantly improved 24-HR PW and QoL across all severities of SUI. Improvements were noted in as little as 2 weeks and appeared to be sustained through 2-year follow up. Registered on ClinTrials.gov (NCT02954042).

The Neuropeptide HGAP Regulates Growth, Reproduction, Metamorphosis, Tissue Damage Repair, and Response against Starvation in Pacific Abalone

Introduction: Neuropeptides regulate vital physiological processes in multicellular organisms, including growth, reproduction, metamorphosis, and feeding. Recent transcriptome analyses have revealed neuropeptide genes with potential roles in vertebrate and invertebrate growth and reproduction. Among these genes, haliotid growth-associated peptide (HGAP) was identified as a novel gene in abalone. Methods: This study focused on HGAP in Pacific abalone (Haliotis discus hannai), where the complete cDNA sequence named Hdh-HGAP was identified and characterized. Samples from different experiments, such as metamorphosis, juvenile abalone growth, gonad development stages, muscle remodeling, and starvation, were collected for mRNA expression analysis. Results: The sequence spans 552 bp, encoding 96 amino acids with a molecular weight of 10.96 kDa. Expression analysis revealed that Hdh-HGAP exhibited higher levels in muscle tissue. Notably, during metamorphosis, Hdh-HGAP exhibited greater expression in the trochophore, veliger, and juvenile stages than in the cell division stages. Regarding growth patterns, Hdh-HGAP was highly expressed during rapid growth compared to stunted, minimal, and normal growth. In gonadal development, Hdh-HGAP mRNA reached its highest expression level during the ripening stage, indicating a potential role in gonadal cell proliferation and maturation. The in vivo effects of GnRH on gonad development and the expression of the Hdh-HGAP neuropeptide indicate its involvement in regulating reproduction in Pacific abalone. While tissue remodeling is primarily governed by immune genes, Hdh-HGAP was also upregulated during muscle tissue remodeling. Conversely, Hdh-HGAP was downregulated during prolonged starvation. Conclusion: This study marks the first comprehensive exploration of the Hdh-HGAP neuropeptide gene in Pacific abalone, shedding light on its involvement in growth, reproduction, metamorphosis, tissue remodeling, and response to starvation, although regulatory mechanisms are mostly unknown.

1-Deoxynojirimycin Mitigates Glycogen and Carbohydrate Metabolic Enzyme Alterations in High Glucose-Induced Diabetic Tilapia: Implications for Therapeutic Intervention

This study investigated the effects of 1- deoxynojirimycin (DNJ) on blood glucose levels, body weight changes, glycogen levels, and carbohydrate marker enzyme activity in a high glucose-induced experimental diabetic tilapia model. We utilized spectrophotometry assay methods to achieve this objective. DNJ treatment significantly reduced blood glucose and mitigated body weight loss compared to the diabetic control group. Furthermore, DNJ treatment increased glycogen levels in liver and muscle tissues, suggesting its potential to enhance glycogen synthesis or reduce glycogen breakdown. DNJ treatment also modulated the activity of carbohydrate marker enzymes, indicating its possible inhibitory effect on enzymes involved in carbohydrate absorption and breakdown, which in turn may improve glucose homeostasis and control. The results of this study highlight DNJ's potential as a therapeutic agent for diseases associated with glycogen metabolism and glucose homeostasis, as well as its ability to influence body weight changes in diabetic conditions. Our findings contribute to the growing body of research on DNJ as a potential therapeutic agent for illnesses linked to glycogen and underscore its therapeutic potential for future treatments targeting glucose metabolism, glycemic control, and weight management.

Social buffering of oxidative stress and cortisol in an endemic cyprinid fish

Fish exhibit complex social behaviours that can influence their stress levels and well-being. However, little is known about the link between social interactions and stress in wild fish, especially in running water environments. While many studies have explored the stress axis in fish, most have focused on specific social contexts, leaving gaps in understanding stress responses to social changes. Our study investigated collective behaviour and stress in wild Italian riffle dace (Telestes muticellus) in a controlled experimental setup simulating a natural river system. Results reveal that group-living fish have lower cortisol and oxidative stress levels in muscle tissue compared to solitary counterparts, suggesting a calming effect of conspecific presence. Additionally, we observed upregulated expression of antioxidant enzymes in group-living fish, indicating potential benefits to antioxidant defence systems. These insights shed light on the dynamic relationship between group behaviour and stress in wild fish within running water habitats and emphasise the use of multidisciplinary approaches.