scholarly journals Temperature, but not excess of glycogen, regulate post-mortem AMPK activity in muscle of steer carcasses

2020 ◽  
Author(s):  
P Strobel ◽  
A Galaz ◽  
F Villaroel-Espíndola ◽  
A Apaoblaza ◽  
JC Slebe ◽  
...  
Keyword(s):  
Muscle Glycogen ◽  
Activity Level ◽  
Post Mortem ◽  
High Ph ◽  
Glycogen Concentration ◽  
Highly Sensitive ◽  
Structural Differences ◽  
Ampk Activity ◽  
Rate Of Decline

AbstractPost-mortem muscle temperature affects the rate of decline in pH in a linear manner from 37.5 °C down near 0 °C, and this pH decline is correlated with the enzymatic degradation of glycogen to lactate. This transformation occurs in an anaerobic context that includes the metabolic splice between glycogenolysis and glycolysis; and both processes are strongly upregulated by AMPK enzyme. In this study we reported changes (0.5 h and 24 h post-mortem) in muscle glycogen concentration, lactate and AMPK activity from 12 samples of Longissimus dorsi from 38 steers that produced high pH (>5.9) and normal pH (<5.8) carcasses at 24 h post-mortem. Moreover, we evaluated changes in AMPK activity in samples from both categories incubated at 37, 25, 17 and 5 °C and supplemented with exogenous glycogen. Finally, we analysed if there were structural differences between polymers from both categories. Our analyses show that enzymatic AMPK activity was significantly higher at 17 °C than at 37 °C or 25 °C (p<0.0001 and p<0.05 in samples from normal and high pH categories, respectively), and was near zero at 5 °C. On the other hand, AMPK activity did not change in relation with excess glycogen and we did not detect structural differences in the polymers present in samples from both categories. We concluded that post-mortem AMPK activity level is highly sensitive to temperature and not at in vitro changes in glycogen concentration. Their results suggest that that normal levels of pre-mortem muscle glycogen and an adequate cooling managing of carcasses are relevant to let an efficient glycogenolytic/glycolytic flow required for lactate accumulation and pH decline, trough of post-mortem AMPK signalling pathway.

scholarly journals Temperature, but not excess of glycogen, regulates “in vitro” AMPK activity in muscle samples of steer carcasses

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0229480
Author(s):  
Pablo Strobel ◽  
Alex Galaz ◽  
Franz Villaroel-Espíndola ◽  
Ariel Apaoblaza ◽  
Juan Carlos Slebe ◽  
...  
Keyword(s):  
Muscle Glycogen ◽  
Incubation Temperature ◽  
Maximum Activity ◽  
High Ph ◽  
Glycogen Concentration ◽  
Metabolic Coupling ◽  
Highly Sensitive ◽  
Structural Differences ◽  
Ampk Activity

Postmortem muscle temperature affects the rate of pH decline in a linear manner from 37.5°C to 0–2°C. The pH decline is correlated with the enzymatic degradation of glycogen to lactate and this process includes the metabolic coupling between glycogenolysis and glycolysis, and that are strongly upregulated by the AMPK. In this study, we used 12 samples previously characterized by have different muscle glycogen concentration, lactate and AMPK activity, selected from 38 steers that produced high final pH (>5.9) and normal final pH (<5.8) carcasses at 24 h postmortem. Moreover, we evaluated changes in the AMPK activity in samples from both categories incubated at 37, 25, 17 and 5°C and supplemented with exogenous glycogen. Finally, we analysed if there were structural differences between polymers from both categories. Our results showed that “in vitro” enzymatic AMPK activity evaluated at both 0.5 or 24 h was greater in samples from normal then high pH categories (p <0.01), and in all temperature of incubation analysed (17, 25 and 37°C). For other hand, a greater AMPK activity were obtained in samples incubated at 17 that 25 or 37°C, in normal carcasses at both 0.5 or 24 h (p < 0.01), as also in samples from carcasses categorized as high pH, but at 24 h (p < 0.05). Interestingly, AMPK activity was totally abolished at 5°C, independent of final pH category of carcasses, and was confirmed that the incubation temperature at which the maximum activity was obtained (p < 0.01), at least in carcasses with a normal pH is at 17°C. The enzymatic AMPK activity did not change in relation to excess glycogen (p > 0.05) and we did not detect structural differences in the polymers present in samples from both categories (p > 0.05), suggesting that postmortem AMPK activity may be highly sensitive to temperature and not to in vitro changes in glycogen concentration (p > 0.05). Our results allow concluding that normal concentrations of muscle glycogen immediately at the time of slaughter (0.5 h) and an adequate cooling managing of carcasses are relevant to let an efficient glycogenolytic/glycolytic flow required for lactate accumulation and pH decline, through the postmortem AMPK signalling pathway.

scholarly journals Effect of Preslaughter Bull Handling on Ante Mortem Muscle Glycogen and Post Mortem pH and Glycogen Level (short communication)

1999 ◽  
Vol 42 (2) ◽  
pp. 135-138
Author(s):  
R. Lahucky ◽  
O. Palanska ◽  
J. Mojto ◽  
K. Zaujec ◽  
J. Huba
Keyword(s):  
Muscle Glycogen ◽  
Short Communication ◽  
Post Mortem ◽  
Glycogen Level ◽  
Glycogen Concentration ◽  
Muscle Glycogen Concentration

Abstract. Forty three bulls (13 Holstein, 12 crosses Holstein x Belgium Blue, 9 Slovak Pied and 9 crosses Slovak Pinzgauer x Piemontese) were taken in this experiment. Thirteen were stressed by mixing overnight before slaughter. Muscle values were analysed for glycogen ante mortem (M. semitendinosus), glycogen and pH post mortem (1 h, 3 h, 48 h) from logissimus dorsi. The ante mortem and post mortem (1 h, 3 h) muscle glycogen concentration was depleted (P < 0.01) in all stressed bulls. Differences (P < 0.01) were found also in pH (48 h). Significant correlations (P < 0.01) between ante mortem and post mortem (1 h, 3 h) muscle glycogen respectivelly and ultimate pH supported the possibility to measure of stress and to predict carcass ultimate pH of bulls.

Glucose tolerance of sheep as related to post-mortem muscle characteristics

1970 ◽  
Vol 21 (6) ◽  
pp. 939 ◽  
Author(s):  
WR Shorthose
Keyword(s):  
Glucose Tolerance ◽  
Plasma Glucose ◽  
Muscle Glycogen ◽  
Glucose Concentration ◽  
Tolerance Test ◽  
Post Mortem ◽  
Muscle Properties ◽  
Rate Of Decline ◽  
Sampling Procedures ◽  
Muscle Glycogen Concentration

The glucose tolerance, expressed as T 1/2, of sheep unaccustomed to blood sampling procedures was negatively correlated with the muscle glycogen concentration of the M. semitendinosus (ST) immediately after death and the extent of glycolysis. T 1/2 was positively correlated with the pH of the ST 24 hr after death. It was suggested that the rate of decline of plasma glucose concentration in a tolerance test was influenced by the animal's response to venipuncture and handling during the test. The extent of the animal's response to this stress was considered to be related to the animal's response to pre-slaughter stress and to account for the correlations between T 1/2 and post-mortem muscle properties.

Effects of high-intensity intermittent swimming on glucose transport in rat epitrochlearis muscle

1998 ◽  
Vol 84 (6) ◽  
pp. 1852-1857 ◽  
Author(s):  
Kentaro Kawanaka ◽  
Izumi Tabata ◽  
Ayumi Tanaka ◽  
Mitsuru Higuchi
Keyword(s):  
Glucose Transport ◽  
Muscle Glycogen ◽  
High Intensity ◽  
Significant Negative Correlation ◽  
Exercise Duration ◽  
Male Rats ◽  
Glycogen Concentration ◽  
Exercise Induced ◽  
Muscle Glycogen Concentration

Recently (K. Kawanaka, I. Tabata, and M. Higuchi. J. Appl. Physiol. 83: 429–433, 1997), we demonstrated that glucose transport activity after repeated 10-s-long in vitro tetani in rat epitrochlearis (Epi) muscle was negatively correlated with the postcontraction muscle glycogen concentration. Therefore, we examined whether high-intensity intermittent swimming, which depletes muscle glycogen to a lower level than that observed after ten 10-s-long in vitro tetani, elicits higher glucose transport than that observed after ten 10-s-long in vitro tetani, which has been regarded as the exercise-induced maximal stimulus for glucose transport. In male rats, 2-deoxy-d-glucose transport rate in Epi muscle after eight bouts of high-intensity intermittent swimming with a weight equal to 18% of body mass (exercise duration: 20 s, rest duration between exercise bouts: 40 s) was higher than that observed after the ten 10-s-long tetani (2.25 ± 0.08 vs. 1.02 ± 0.16 μmol ⋅ ml intracellular water−1 ⋅ 20 min−1). Muscle glycogen concentration in Epi after eight bouts of high-intensity intermittent swimming was significantly lower than that observed after ten 10-s-long in vitro tetani (7.6 ± 0.5 vs. 14.8 ± 1.4 μmol glucose/g muscle). These observations show that the high-intensity intermittent swimming increases glucose transport in rat Epi to a much higher level than that induced by ten 10-s-long in vitro tetani, which has been regarded as the exercise-related maximal stimulus for glucose transport. Furthermore, this finding suggests that the lower muscle glycogen level after high-intensity intermittent swimming than after in vitro tetani may play a role, because there was a significant negative correlation between glucose transport and muscle glycogen concentration in Epi after high-intensity swimming and in vitro tetani.

scholarly journals Computational Design of a Molecularly Imprinted Polymer for the Biomonitoring of the Organophosphorous Metabolite Chlorferron

Biosensors ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 192
Author(s):  
Bakhtiyar Qader ◽  
Issam Hussain ◽  
Mark Baron ◽  
Rebeca Jiménez-Pérez ◽  
Guzmán Gil-Ramírez ◽  
...  
Keyword(s):  
Biological Samples ◽  
Limit Of Detection ◽  
Computational Design ◽  
Signal Change ◽  
Highly Sensitive ◽  
Limit Of Quantitation ◽  
Molecularly Imprinting Polymers ◽  
Mip Sensor ◽  
Parasitic Mites

Coumaphos is an organophosphorus compound used as insecticide and frequently used by beekeepers for the management of parasitic mites. The most important metabolite, chlorferron (CFN), has been identified in biological samples and foodstuff. The need to quickly identify the presence of typical metabolites, as an indication of interaction with coumaphos has driven the need to produce a highly sensitive electrochemical method for chlorferron analysis, based on molecularly imprinting polymers (MIP) technology. It showed irreversible behaviour with mixed diffusion/adsorption-controlled reactions at the electrode surface. A monoelectronic mechanism of reaction for oxidation has also been suggested. The linear range observed was from 0.158 to 75 µM. Median precision in terms of %RSD around 3% was also observed. For DPV, the limit of detection (LOD) and the limit of quantitation (LOQ) for the CFN-MIP were 0.158 µM and 0.48 µM, respectively. The obtained median % recovery was around 98%. The results were also validated to reference values obtained using GC-MS. Urine and human synthetic plasma spiked with CFN were used to demonstrate the usability of the method in biological samples, showing the potential for biomonitoring. The developed imprinted sensor showed maximum signal change less than 16.8% when related metabolites or pesticide were added to the mix, suggesting high selectivity of the MIP sensor toward CFN molecules. The results from in vitro metabolism of CMP analysed also demonstrates the potential for detection and quantification of CFN in environmental samples. The newly developed CFN-MIP sensor offers similar LoDs than chromatographic methods with shorter analysis time.

scholarly journals Nanoimprinted multifunctional nanoprobes for a homogeneous immunoassay in a top-down fabrication approach

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hubert Brueckl ◽  
Astrit Shoshi ◽  
Stefan Schrittwieser ◽  
Barbara Schmid ◽  
Pia Schneeweiss ◽  
...  
Keyword(s):  
Thin Film ◽  
Nanoimprint Lithography ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
In Vitro Diagnostics ◽  
Top Down ◽  
Highly Sensitive ◽  
Optical And Magnetic Properties ◽  
Lift Off

AbstractMultifunctional nanoparticles are discussed as versatile probes for homogeneous immunoassays for in-vitro diagnostics. Top-down fabrication allows to combine and tailor magnetic and plasmonic anisotropic properties. The combination of nanoimprint lithography, thin film deposition, and lift-off processing provides a top-down fabrication platform, which is both flexible and reliable. Here, we discuss the material compositions and geometrical designs of monodisperse multicomponent nanoparticles and their consequences on optical and magnetic properties. The rotational hydrodynamics of nanoparticles is measured and considered under the influence of magnetic shape anisotropy in the framework of the Stoner-Wohlfarth theory. The plasmon-optical properties are explained by discrete-dipole finite-element simulations. Rotational dynamical measurements of imprinted nanoprobes for two test proteins demonstrate the applicability as highly sensitive biomolecular nanoprobes.

scholarly journals Modulatory Effects of Caffeine and Pentoxifylline on Aromatic Antibiotics: A Role for Hetero-Complex Formation

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3628
Author(s):  
Anna Woziwodzka ◽  
Marta Krychowiak-Maśnicka ◽  
Grzegorz Gołuński ◽  
Anna Felberg ◽  
Agnieszka Borowik ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Drug Repurposing ◽  
Activity Level ◽  
Titration Calorimetry ◽  
Human Pathogens ◽  
Neighborhood Association ◽  
Treatment Regimens ◽  
Vis Spectroscopy ◽  
Antibiotic Interactions

Antimicrobial resistance is a major healthcare threat globally. Xanthines, including caffeine and pentoxifylline, are attractive candidates for drug repurposing, given their well-established safety and pharmacological profiles. This study aimed to analyze potential interactions between xanthines and aromatic antibiotics (i.e., tetracycline and ciprofloxacin), and their impact on antibiotic antibacterial activity. UV-vis spectroscopy, statistical-thermodynamical modeling, and isothermal titration calorimetry were used to quantitatively evaluate xanthine-antibiotic interactions. The antibacterial profiles of xanthines, and xanthine-antibiotic mixtures, towards important human pathogens Staphylococcus aureus, Enterococcus faecium, Escherichia coli, Acinetobacter baumannii, Klebsiella pneumoniae, and Enterobacter cloacae were examined. Caffeine and pentoxifylline directly interact with ciprofloxacin and tetracycline, with neighborhood association constant values of 15.8–45.6 M−1 and enthalpy change values up to −4 kJ·M−1. Caffeine, used in mixtures with tested antibiotics, enhanced their antibacterial activity in most pathogens tested. However, antagonistic effects of caffeine were also observed, but only with ciprofloxacin toward Gram-positive pathogens. Xanthines interact with aromatic antibiotics at the molecular and in vitro antibacterial activity level. Given considerable exposure to caffeine and pentoxifylline, these interactions might be relevant for the effectiveness of antibacterial pharmacotherapy, and may help to identify optimal treatment regimens in the era of multidrug resistance.

scholarly journals Innovative and Highly Sensitive Detection of Clostridium perfringens Enterotoxin Based on Receptor Interaction and Monoclonal Antibodies

Toxins ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 266
Author(s):  
Thea Neumann ◽  
Maren Krüger ◽  
Jasmin Weisemann ◽  
Stefan Mahrhold ◽  
Daniel Stern ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Clostridium Perfringens ◽  
Food Poisoning ◽  
Receptor Interaction ◽  
Clostridium Perfringens Enterotoxin ◽  
Fast Detection ◽  
Highly Sensitive ◽  
Basic And Applied Research ◽  
Highly Sensitive Detection

Clostridium perfringens enterotoxin (CPE) regularly causes food poisoning and antibiotic-associated diarrhea; therefore, reliable toxin detection is crucial. To this aim, we explored stationary and mobile strategies to detect CPE either exclusively by monoclonal antibodies (mAbs) or, alternatively, by toxin-enrichment via the cellular receptor of CPE, claudin-4, and mAb detection. Among the newly generated mAbs, we identified nine CPE-specific mAbs targeting five distinct epitopes, among them mAbs recognizing CPE bound to claudin-4 or neutralizing CPE activity in vitro. In surface plasmon resonance experiments, all mAbs and claudin-4 revealed excellent affinities towards CPE, ranging from 0.05 to 2.3 nM. Integrated into sandwich enzyme-linked immunosorbent assays (ELISAs), the most sensitive mAb/mAb and claudin-4/mAb combinations achieved similar detection limits of 0.3 pg/mL and 1.0 pg/mL, respectively, specifically detecting recombinant CPE from spiked feces and native CPE from 30 different C. perfringens culture supernatants. The implementation of mAb- and receptor-based ELISAs into a mobile detection platform enabled the fast detection of CPE, which will be helpful in clinical laboratories to diagnose diarrhea of assumed bacterial origin. In conclusion, we successfully employed an endogenous receptor and novel high affinity mAbs for highly sensitive and specific CPE-detection. These tools will be useful for both basic and applied research.

The potential digestibility of cellulose in grasses and its relationship with chemical and anatomical parameters

1972 ◽  
Vol 78 (3) ◽  
pp. 457-464 ◽  
Author(s):  
R. J. Wilkins
Keyword(s):  
Floral Development ◽  
Lignin Content ◽  
Leaf Sheath ◽  
Vascular Bundles ◽  
Cellulose Digestibility ◽  
Wimmera Ryegrass ◽  
Rate Of Decline ◽  
The Relationship ◽  
Anatomical Parameters

SUMMARYPotential cellulose digestibility, measured by incubation in vitrofor 6 days, decreased during floral development in perennial ryegrass, Wimmera ryegrass, cocksfoot, oat and tall fescue. The rate of decline was slower than for cellulose digestibility measured after incubation in vitro for 2 days only. Morphological fractions ranked in order of descending potential cellulose digestibility – leaf blade, inflorescence, leaf sheath and stem.Lignin content was determined chemically by the method of Van Soest (1963) and lignified tissue was assessed by staining transverse sections of leaf blades and leaf sheaths with safranin and fast green. Both lignin and lignified tissue increased with maturity. Lignified tissue increased mainly through increase in the number of scleren-chyma cells, but was also affected by the formation of lacunae or cavities between the vascular bundles in leaf blades of cocksfoot and in leaf sheaths of all species studied. For 19 samples of leaf blades and leaf sheaths, potential cellulose digestibility had significant negative correlations with both lignin content (r = -0·862) and lignified tissue (r = -0·905). Limitations to the techniques used to assess lignification and further factors which may affect the relationship between lignification and potential cellulose digestibility are discussed.

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