Muscle Glycogen Levels Research Articles

Effects of different ratios of crude protein and non-fibrous carbohydrates on growth, metabolism, physiology, nutrient utilization and muscle cellularity of Lophiosilurus alexandri, a carnivorous freshwater fish

The aim of this research was to evaluate the effects of different ratios of crude protein/non-fibrous carbohydrates (CP/NFC) on growth, metabolism, physiology, nutrient utilization efficiency and muscle cellularity of juvenile Lophiosilurus alexandri. Treatments consisted of isoenergetic diets (4500 kcal/kg) with CP/NFC ratios of 0.78; 1.02; 1.26 and 1.60, delivered for 75 days. Polynomial regression analysis showed that the different CP/NFC ratios affected weight gain and specific growth rate with estimated maximum values of 1.27 and 1.25, respectively. Feed conversion rate and the hepatosomatic index had minimum values with CP/NFC ratios of 1.33 and 1.02, respectively. Muscle and liver glycogen levels were maximized with CP/NFC content of 0.87 and 1.26, respectively. The CP/NFC ratio of 1.20 maximized the deposition of lipids in the muscle while that of 1.11 maximized the concentration of total soluble proteins in the same tissue. Plasma total cholesterol, non-HDL cholesterol and triglycerides increased linearly with increasing dietary CP/NFC ratio. Ratios estimated at 0.99, 0.94, 0.93 and 0.98 minimize the concentrations of HDL, total protein, alanine aminotransferase and creatinine in fish plasma, respectively. Nucleus diameter of hepatocytes increased linearly with increasing dietary CP/NFC ratio, while percentage of liver tissue nuclei decreased linearly. Hypertrophic muscle fibers were influenced by diets with the estimated ratio of 1.21 CP/NFC maximizing the occurrence of these fibers. Fish body crude protein increased linearly with increasing CP/NFC ratios in the diet. Fish body content of mineral matter, total phosphorus and visceral fat were minimized with the ratios of 1.34, 1.38 and 1.12, respectively. There were no effects of CP/NFC ratios on the viscerosomatic index, feed intake, carcass yield, the enzymes aspartate aminotransferase and gamma-glutamyl transferase, percentages of cytoplasmic and capillary sinusoids in liver tissue, and body dry matter, crude energy, total lipids, viscera dry matter. It is concluded that diets containing CP/NFC within 1.11–1.33 improve productive performance and nutrient use efficiency of fish. The different CP/NFC ratios also interfere with some plasma and metabolic variables that, associated with performance results, indicate a better physiological state of juvenile L. alexandri with an initial average weight of 30 g.

Effect of ice stunning versus electronarcosis on stress response and flesh quality of rainbow trout

In recent years, concerns about fish welfare have increased in aquaculture, most pointedly regarding the slaughter process. Immersion in ice water (live chilling) is still commonly used as a stunning method in salmonids, but can have negative effects on the stress response and flesh quality. A valid alternative is electronarcosis, but the specific details of the intensity and frequency of the current applied depend on the species and size, and little is known about how that may affect fish welfare or product quality. In this study, adult rainbow trout (294 ± 8.44 g average weight) were subjected to three different stunning methods before slaughter: immersion in ice water and electronarcosis at two different current intensities (200 or 400 mA). Electronarcosis caused fish to lose consciousness faster than those live chilled. Plasma concentration of cortisol was lower in fish stunned with 400 mA (400 mA: 5.2 ± 0.67 vs. Ice: 9.1 ± 0.90; 200 mA: 9.3 ± 1.20 ng/ml). Creatine-phosphokinase enzyme levels were higher in ice stunned fish compared to electronarcosis (Ice: 168 ± 2.32 vs. 200 mA: 114 ± 0.89; 400 mA: 104 ± 0.62 U/l). Regarding flesh quality, initial muscle pH was lower in fish stunned by ice immersion than by electronarcosis (Ice: 6.49 ± 0.034 vs. 200 mA: 6.76 ± 0.050; 400 mA: 6.61 ± 0.04), presenting also an earlier onset of rigor mortis. Fish stunned with 400 mA electronarcosis also presented higher levels of muscle glycogen than those stunned with ice water (0.181 ± 0.029 vs. 0.101 ± 0.013 mg/g). In conclusion, electronarcosis is a stunning method that can produce an immediate loss of consciousness in rainbow trout, reducing stress response before slaughter and improving flesh quality (with higher benefits using a current intensity of 400 mA), in contrast to immersion in ice water.

Dietary Supplementation with Exogenous Sea-Cucumber-Derived Ceramides and Glucosylceramides Alleviates Insulin Resistance in High-Fructose-Diet-Fed Rats by Upregulating the IRS/PI3K/Akt Signaling Pathway.

Endogenous ceramide is considered to be associated with the progress of insulin resistance. However, the effects of dietary exogenous glucosylceramides and ceramides on insulin resistance are unclear. A model of fructose-induced male Sprague Dawley rats was used to compare the effects of sea-cucumber-derived glucosylceramides and ceramides on insulin resistance. Both glucosylceramides and ceramides significantly improved glucose tolerance, reduced the concentrations of serum glucose and glycosylated hemoglobin, and alleviated the accompanied hypertension. Ceramides significantly enhanced glycogen levels in skeletal muscle, whereas glucosylceramides significantly increased the hepatic glycogen levels. Moreover, glucosylceramides alleviated insulin resistance by inhibiting gluconeogenesis, promoting glycogen synthesis and insulin signal transduction in the liver; meanwhile, ceramides were mainly due to the promotion of glycogen synthesis and insulin signal transduction in skeletal muscle. Additionally, glucosylceramides and ceramides effectively attenuated inflammation in adipose tissue. These results indicate that glucosylceramides and ceramides have potential value in the prevention and alleviation of insulin resistance.

Long-term kappa-carrageenan consumption leads to moderate metabolic disorder by blocking insulin binding

Carrageenan (CGN) is a common food additive, and questions have been raised regarding its safety for human consumption. The purpose of this study was to investigate the impact of κ-CGN on glucose intolerance and insulin resistance from the perspective that κ-CGN may interfere with insulin receptor function and affect insulin sensitivity and signaling, thereby leading to body weight loss. The health effects of κ-CGN on C57BL/6 mice were assessed over a 90-d period by monitoring changes in body weight, glucose tolerance, insulin tolerance, fasting glucose and insulin levels, and expression of insulin-pathway-related proteins. Furthermore, HepG2 cells were used to detect the binding of κ-CGN on insulin receptor and measure its effect on downstream signal transduction. In mice, κ-CGN treatment reduced weight gain without affecting food intake. Glucose and insulin tolerance tests revealed that κ-CGN treatment increased blood glucose levels and glycosylated hemoglobin levels, while hepatic and muscle glycogen levels were decreased, suggesting that κ-CGN affected glucose metabolism in mice. Interestingly, κ-CGN treatment did not cause typical diabetic symptoms in mice, as indicated by low levels of fasting and postprandial blood glucose, in addition to normal pancreatic tissue and insulin secretion. The binding studies revealed that κ-CGN could competitively bind to the insulin receptor with FITC-insulin and thereby disrupt PI3K and Akt activation, thus suppressing expression of glucose transporters and glycogen synthase. In summary, this study revealed that κ-CGN reduced weight gain without affecting food intake, but impaired glucose metabolism in mice by interfering with insulin binding to receptors, thereby affecting the sensitivity of insulin and inhibiting the insulin PI3K/AKT signaling pathway, causing non-diabetic weight gain reduction.

Effects of glucose ingestion at different frequencies on glycogen recovery in mice during the early hours post exercise

BackgroundWhen a high-carbohydrate diet is ingested, whether as small frequent snacks or as large meals, there is no difference between the two with respect to post-exercise glycogen storage for a period of 24 h. However, the effect of carbohydrate intake frequency on glycogen recovery a few hours after exercise is not clear. Athletes need to recover glycogen quickly after physical exercise as they sometimes exercise multiple times a day. The aim of this study was to determine the effect of carbohydrate intake at different frequencies on glycogen recovery during the first few hours after exercise.MethodsAfter 120 min of fasting, 6-week-old male ICR mice were subjected to treadmill running exercise (20 m/min for 60 min) to decrease the levels of muscle and liver glycogen. Mice were then given glucose as a bolus (1.2 mg/g of body weight [BW], immediately after exercise) or as a pulse (1.2 mg/g of BW, every 15 min × 4 times). Following this, the blood, tissue, and exhaled gas samples were collected.ResultsIn the bolus group, blood glucose concentration was significantly lower and plasma insulin concentration was significantly higher than those in the pulse group (p < 0.05). The plantaris muscle glycogen concentration in the bolus group was 25.3% higher than that in the pulse group at 60 min after glucose ingestion (p < 0.05). Liver glycogen concentration in the pulse group was significantly higher than that in the bolus group at 120 min after glucose ingestion (p < 0.05).ConclusionsThe present study showed that ingesting a large amount of glucose immediately after exercise increased insulin secretion and enhanced muscle glycogen recovery, whereas frequent and small amounts of glucose intake was shown to enhance liver glycogen recovery.

Lactose-riched Mongolian mare's milk improves physical fatigue and exercise performance in mice.

Fatigue may cause the efficiency of the organ in human body to decrease, which may affect the daily life and exercise performance of the general people and athletes. Mare's milk powder (MMP) is a lactose rich supplement. The research of the study is to evaluate the whether MMP has anti-fatigue effect. Forty male ICR mice were randomly divided into four group to receive vehicle or MMP by oral gavage at 0 (Vehicle), 0.27 (MMP-1X), 0.54 (MMP-2X), 1.35 (MMP-5X) g/kg/day for 14 days. The forelimb grip of the MMP-2X, and MMP-5X group were significantly higher than the vehicle group. The swim-to-exhaustion times of the MMP-1X, MMP-2X, and MMP-5X group were significantly greater than the vehicle group. Glycogen levels in liver and muscle were significantly larger in the MMP-1X, MMP-2X, and MMP-5X groups than the vehicle group. Receive MMP supplement for 14 days can promoting exercise performance and amelioration of exercise-induced fatigue.

Industrial applications of selected JFS articles

Industrial applications of selected <i>JFS</i> articles

Antifatigue effect of functional cookies fortified with mushroom powder (Tricholoma Matsutake) in mice.

Bakery products made by cereal and edible fungi powder have a unique flavor and health benefits, dramatically enhancing the nutritional value of the products. In this study, we investigated the antifatigue effect of a novel Tricholoma matsutake cookie (TMC) by the exhaustive swimming test. Male Kunming ICR mice were randomly divided into seven groups (each group, n = 10), fed with saline, ordinary cookies (4, 8, 16g/kg B.W./day), and TMC (4, 8, 16g/kg B.W./day) by gavage. After 30-day administration, the weight-loaded swimming test was carried out on the mice to evaluate the antifatigue effect of TMC. In comparison with the effect of ordinary cookies, the intake of TMC significantly prolonged the exhaustive swimming time of mice and increased the level of muscle glycogen and liver glycogen, accompanied by the reduction of lactic acid and urea nitrogen level in serum. Additionally, TMC dramatically improved the activity of superoxide dismutase and glutathione peroxidase in serum and largely decreased the level of malondialdehyde. All in all, TMC could enforce exhaustive swimming tolerance, accelerate the decomposition of sports-related metabolites such as lactic acid and urea nitrogen, and increase the activity of the antioxidant enzyme, thereby improving sports-related energy storage and relieving fatigue. Our findings broadened the application of T. matsutake in the processing of bakery products and provided the theoretical basis and technical support for the development of antifatigue products. PRACTICAL APPLICATION: In this study, we investigated the antifatigue effect of a novel Tricholoma matsutake cookie by the exhaustive swimming test. Collectively, the results of the present study suggested that the cookies fortified with T. matsutake could be considered as an antifatigue bakery product. Furthermore, our findings broadened the application of T. matsutake in the processing of bakery products and provided the theoretical basis and technical support for the development of antifatigue products.

Polysorbate 80-induced leaky gut impairs skeletal muscle metabolism in mice.

Impaired intestinal permeability can induce systemic inflammation and metabolic disturbance. However, the effect of impaired intestinal permeability on metabolic function in the skeletal muscle is unknown. Dietary polysorbate 80 (PS80), a common emulsifier, has been shown to impair intestinal permeability in mice. Here, we investigated the effect of PS80‐induced intestinal permeability on glucose tolerance with metabolic signaling in the skeletal muscle. Male ICR mice were divided into control and PS80 groups. In the PS80 group, PS80 was contained in the drinking water at 1% (w/v). After 4 weeks, plasma fluorescein isothiocyanate (FITC) intensity was measured after orally administering FITC‐dextran. Half of the mice in each group underwent running exercises. Metabolic and inflammatory parameters were examined in the blood and skeletal muscle. Plasma FITC and lipopolysaccharide levels were higher in the PS80 group than the control group (p < .01, p = .085). The expression of tumor necrosis factor‐α in the skeletal muscle was increased upon PS80 administration (p < .05). Although the homeostasis model assessment ratio was higher in the PS80‐fed mice (p < .05), insulin‐signaling activity in the muscle did not differ between groups. Muscular pH, mitochondrial cytochrome oxidase activity, and glycogen content after exercise were lower in the PS80 group (p < .05) than the control group. There was a negative correlation between plasma FITC and muscle glycogen levels in the exercised groups (r = −.60, p < .05). These results suggest that daily PS80 intake induces intestinal permeability, leading to glucose intolerance and mitochondrial dysfunction in the skeletal muscle.

Erythromycin has therapeutic efficacy on muscle fatigue acting specifically on orosomucoid to increase muscle bioenergetics and physiological parameters of endurance

At present, there are still no official or semi-official recommendations for the treatment of muscle fatigue. We previously reported that acute phase protein orosomucoid (ORM) can enhance muscle endurance and exert anti-fatigue effect. In attempting to seek anti-fatigue drugs that target ORM, we found macrolide antibiotics, particularly erythromycin, were effective. Erythromycin can significantly prolong the time of mice forced-swimming and treadmill running, increase muscle fatigue index, alleviate fatigue-induced tissue damage, and elevate glycogen content, mitochondria function and ATP level in the muscle. Also, erythromycin increases ORM protein expression in a dose- and time- dependent manner both in vitro and in vivo. Further studies found that erythromycin could increase the activity of ORM promoter and the stability of ORM mRNA, which might both be responsible for the ORM up-regulation. ORM knockdown or knockout could abolish the promoting effect of erythromycin in mice forced-swimming time, muscle fatigue index and glycogen level. Furthermore, those effects were also abolished in mice with C-C motif chemokine receptor 5 (CCR5) antagonist administration or AMPKα2 deficiency. Therefore, erythromycin could enhance muscle glycogen and endurance via up-regulating the level of ORM and activating CCR5-AMPK pathway, indicating it might act as a potential drug to treat muscle fatigue.

Organic and conventional agriculture: Conventional rice farming causes biochemical changes in Astyanax lacustris

World food production is directly related to human population growth. Chemicals are constantly applied to pest control in crops to increase productivity. Therefore, sustainable alternatives are needed to reduce environmental impacts. The biochemical responses in liver and muscle of Astyanax lacustris collected in different rice planting systems were analysed. Ten fish were collected in organic rice cultivation systems and conventional as well as water and sediment for pesticide analysis. In water from conventional system, bentazon (56.1 μg L−1), fipronil (0.226 μg L−1) and propoxur (0.141 μg L−1) were found, while azoxystrobin and quinclorac were below the limit of quantification (LOQ). There were no pesticides in the sediment from the conventional system. In the water of the organic system, only propoxur (below the LOQ) was registered. Metalaxil (0.025 μg kg−1) were verified in the sediment, while diphenoconazole, dinoxifene and tebuconazole were below the LOQ. The presence of these pesticides in crops with an organic production system may be related to proximity to crops to conventional production systems. Besides this, the amount is very low as compared with conventional system. Muscle glycogen, protein and amino acid levels were higher in fish collected in organic ponds. Lactate and ammonia levels were higher in conventional cultures. Lipids and proteins had greater oxidative damage in both tissues in the conventional system. Although pesticides were detected in organic sediments, the parameters of metabolic and oxidative damage were probably related by exposure to higher concentrations of pesticide in the water or by the lower oxygen content of conventional systems. However, fish mortality was not observed during collections. Despite being an anthropic environment, areas of organic cultivation seem to present better conditions for the survival of A. lacustris.

Effects of different dietary carbohydrate‐to‐lipid ratios on growth, plasma biochemical indexes, digestive and immune enzymes activities of juvenile orange‐spotted grouper Epinephelus coioides

An 8-week feeding trial was conducted to investigate the effects of dietary carbohydrate-to-lipid (CHO:L) ratios on growth, liver and muscle glycogen content, haematological indices, and liver and intestinal enzyme activity of juvenile grouper (Epinephelus coioides). Five isonitrogenous (496.0 g/kg protein) and isoenergetic (21.6 KJ/g gross energy) diets with varying CHO:L ratios of 0.65 (D1), 1.31 (D2), 2.33 (D3), 4.24 (D4) and 8.51 (D5), respectively, were fed to triplicate groups of 20 fish (average 10.02 ± 0.1 g) for 8 weeks. Results showed that the weight gain rate, specific growth rate and protein efficiency ratio (PER) of juvenile grouper increased first and then decreased with the increase in CHO:L ratio, reaching a maximum value in the D4 (CHO:L = 4.24) diet. The trend for the feed conversion ratio was opposite to the PER. Along with the diet CHO:L ratios, the apparent digestibility coefficients (ADC) of crude lipid and energy for the juvenile groupers decreased gradually, while the ADC of dry matter, liver and muscle glycogen level increased gradually. Total protein, triglycerides and cholesterol in serum were all maximized in the D4 diet and glucose in the D5 (CHO:L = 8.51) diet. Digestive enzyme activity in the intestine was significantly affected by dietary CHO:L ratio. Liver hexokinase, phosphofructokinase and glucose-6-phosphate dehydrogenase activity increased significantly as CHO:L ratio increased. Liver lysozyme and acid phosphatase activity in the groupers fed the D3 (CHO:L = 2.33) diet was significantly higher than that of other diets. Liver fructose-1,6-bisphosphatase and alkaline phosphatase activity reached a maximum value in the D4 diet and was significantly higher than that in the D1 diet. Taking the above results together, it can be concluded that an optimal dietary CHO:L ratio of 2.33 is suitable for grouper culture concerning growth performance and health.

MondoA Is Required for Normal Myogenesis and Regulation of the Skeletal Muscle Glycogen Content in Mice

BackgroundSkeletal muscle is the largest tissue in the human body, and it plays a major role in exerting force and maintaining metabolism homeostasis. The role of muscle transcription factors in the regulation of metabolism is not fully understood. MondoA is a glucose-sensing transcription factor that is highly expressed in skeletal muscle. Previous studies suggest that MondoA can influence systemic metabolism homeostasis. However, the function of MondoA in the skeletal muscle remains unclear.MethodsWe generated muscle-specific MondoA knockout (MAKO) mice and analyzed the skeletal muscle morphology and glycogen content. Along with skeletal muscle from MAKO mice, C2C12 myocytes transfected with small interfering RNA against MondoA were also used to investigate the role and potential mechanism of MondoA in the development and glycogen metabolism of skeletal muscle.ResultsMAKO caused muscle fiber atrophy, reduced the proportion of type II fibers compared to type I fibers, and increased the muscle glycogen level. MondoA knockdown inhibited myoblast proliferation, migration, and differentiation by inhibiting the phosphatase and tensin homolog (PTEN)/phosphoinositide 3-kinase (PI3K)/Akt pathway. Further mechanistic experiments revealed that the increased muscle glycogen in MAKO mice was caused by thioredoxin-interacting protein (TXNIP) downregulation, which led to upregulation of glucose transporter 4 (GLUT4), potentially increasing glucose uptake.ConclusionMondoA appears to mediate mouse myofiber development, and MondoA decreases the muscle glycogen level. The findings indicate the potential function of MondoA in skeletal muscle, linking the glucose-related transcription factor to myogenesis and skeletal myofiber glycogen metabolism.

Effects of different dietary carbohydrate-to-lipid ratios on growth, plasma biochemical indexes, digestive, and immune enzymes activities of sub-adult orange-spotted grouper Epinephelus coioides.

A 10-week feeding trial was conducted to investigate the effects of dietary carbohydrate-to-lipid (CHO:L) ratios on glycogen content, hematological indices, liver, and intestinal enzyme activity of sub-adult grouper Epinephelus coioides. Five iso-nitrogenous (496.0gkg-1 protein) and iso-energetic (21.6KJg-1 gross energy) diets with varying CHO: L ratios of 0.65 (D1), 1.31 (D2), 2.33 (D3), 4.24 (D4), and 8.51 (D5), respectively, were fed to triplicate groups of 20 fish (average 275.1 ± 1.86g). Results showed that the weight gain rate (WGR), specific growth rate (SGR), and protein efficiency ratio (PER) of sub-adult grouper increased and then stable when dietary CHO:L ratios reach D4 (CHO:L = 4.24). The trend of feed conversion ratio (FCR) was opposite to PER. Along with the dietary CHO:L ratios, the liver and muscle glycogen level increased gradually. Plasma triglycerides (TG) and glucose (GLU) were all maximized at D5 (CHO:L = 8.51) group, cholesterol (CHOL) at D4 (CHO:L = 4.24) group. Digestive enzyme activities were significantly affected by dietary CHO:L ratios. Liver hexokinase (HK), alkaline phosphatase (AKP), and glucose-6-phosphate dehydrogenase (G6PDH) activity increased significantly as CHO:L ratios increased. Liver lysozyme (LYZ) and superoxide dismutase (SOD) activity of sub-adult grouper fed the D4 diet was significantly higher than that of the D2 (CHO:L = 1.31) diet. The trend of acid phosphatase (ACP) is opposite to AKP. The regression model analysis showed that the most suitable dietary CHO:L ratio to reach the highest SGR is 6.06.

Safety and influence of a novel powder form of coconut inflorescence sap on glycemic index and lipid profile

Carbohydrates are the primary source of energy for human body. Carbohydrates increase resting muscle glycogen levels and help in delaying muscle fatigue. But, higher intake of high glycemic carbohydrates may lead to complications, if not balanced by physical activities. Our earlier studies have indicated that a proprietary powder preparation of coconut inflorescence sap (COCOZEN™, abbreviated as ‘CSP’ meaning ‘coconut sap powder’) contains relatively higher levels of micronutrients and possess antioxidant, anti-inflammatory, nephroprotective, hepatoprotective, gastroprotective and ergogenic activities. Thus, the present study was aimed to investigate the safety and efficacy of CSP (15 g/day for 90 days) on healthy and nonathletic subjects (n = 20). The study was performed in two phases. In the first phase, glycemic index (GI) was measured using glucose as a reference standard. In the second phase, CSP was supplemented at (15g × 1)/day dosage for 90 days and monitored the anthropometric parameters, adverse events, blood sugar levels (fasting and postprandial), blood pressure, and other routine hematological and biochemical parameters. It was observed that CSP possess a GI of 52.47 and is safe with an acceptable sensory attribute. It did not contribute any side effects or deviations in blood sugar or other hematological and biochemical parameters, except in Hb and lipid profile which showed significant (p < 0.05) enhancement.

Seasonal variations in the hemocyte parameters, gonad development, energy storage and utilization of the giant honeycomb oyster Hyotissa hyotis (Linnaeus 1758) in Jeju Island off the south coast of Korea

Hyotissa hyotis is a gryphaeid oyster distributed from the Indo-Pacific to Eastern Pacific regions. This oyster has extended its distribution range from tropical and subtropical waters to Jeju Island off the south coast of Korea, possibly due to the recent increase in seawater temperature. This species is considered to be an aquaculture candidate due to its fast growth and high-quality adductor muscle. In the present study, we first investigated seasonal changes of gonad development, energy storage and utilization, and hemocyte functions of H. hyotis on Jeju Island off the south coast of Korea. The taxonomic status of the specimen was confirmed by nucleotide sequencing of the mitochondrial 16S ribosomal genes. Histology indicated that gametogenesis of male and female oysters commenced in May and June, respectively, when the water temperature reached 16.0–18.2 °C. Partially spawned oysters were evident from September to November, when the water temperature was 21–22 °C. H. hyotis had an extraordinarily large adductor muscle, which accounted for 47.6–55.6 % of its total body weight. The ratio of adductor muscle weight to total body weight varied seasonally, and was negatively correlated with maturation of the gonad. Glycogen levels in the adductor muscle were significantly higher than the levels in other tissues and strongly fluctuated during gametogenesis, indicating that the adductor muscle plays a critical role as a major energy storage organ. Finally, post-spawning oysters showed a weakening of cellular defense capacities, characterized by the decreased phagocytic capacity and increased mortality of hemocytes.

Anti-fatigue effect of aqueous extract of Hechong (Tylorrhynchus heterochaetus) via AMPK linked pathway

Tylorrhynchus heterochaetus (Hechong in Chinese) has been used in Chinese traditional medicine for treating various diseases. This study was aimed to assess the anti-fatigue effect of T. heterochaetus on Kunming mice and its primary mechanism of action using forced running, rotating rod and weight-loaded swimming tests. Low (2.70 mg/0.5 mL/20 g), medium (5.41 mg/0.5 mL/20 g) and high (6.58 mg/0.5 mL/20 g) doses of T. heterochaetus aqueous extract were treated to mice for 28 days. Among the doses, the low and medium doses showed significant (p ≤ 0.05) anti-fatigue effect on the weight-loaded swimming test. Also, T. heterochaetus extract showed significant (p ≤ 0.05) effects on fatigue-related blood parameters by increasing the GLU, TG and LDH levels and decreasing the LA, CK and BUN levels. The levels of liver and skeletal muscle glycogen were also significantly (p ≤ 0.05) increased after treatment. Further, on Western blot analysis, it has been found that T. heterochaetus enhanced the expressions of AMPK and PGC-1α in the liver and skeletal muscles of mice. From the study, our outcomes suggest that T. heterochaetus possess an anti-fatigue effect through the AMPK-linked pathway and thereby it can regularize the energy metabolism.

Evaluation of antifatigue and antioxidant activities of the marine microalgae Isochrysis galbana in mice.

The present work aimed to estimate the possible anti-fatigue effect and potential mechanism of Isochrysis galbana (IG) in mice. The anti-fatigue activity of IG (100, 200, and 400mg/kg) was elucidated by a weight-loaded forced swimming test, and the potential mechanism was explored by determination of fatigue-related biochemical parameters. The results showed that pretreatment with IG significantly extended the exhaustive swimming time and increased the levels of liver glycogen, muscle glycogen and blood glucose in a dose-dependent manner. Besides, the increased levels of alanine aminotransferase, aspartate aminotransferase, blood lactic acid, lactic dehydrogenase, creatine kinase, and blood urea nitrogen by exhausted swimming, were dramatically attenuated by pretreatment with IG. Furthermore, supplementation with IG significantly enhanced the glutathione peroxidase and superoxide dismutase levels, while attenuated the level of malonaldehyde. Taken together, IG possessed appreciable efficacy to alleviate fatigue, and the mechanism might be associated with favorably modulating the process of energy consumption, metabolism, and attenuating oxidative stress injury.

Use of eugenol for the anaesthesia and transportation of freshwater angelfish (Pterophyllum scalare)

This study aimed to evaluate the effectiveness of eugenol for the induction and anaesthesia recovery of freshwater angelfish juveniles, and to verify its effectiveness for transportation. Juveniles were exposed to different concentrations of eugenol: 0 (control), 10, 15, 20, 30, 40, 50 and 60 μL L−1 (equivalent to 10.6, 15.9, 21.2, 31.8, 42.4, 53.0 or 63.6 mg L−1). Afterwards, other fish were divided into two groups: sedated with 15.9 mg L−1 eugenol and non-sedated, and they were evaluated 4 and 7 h after transportation. The minimum effective concentration for sedation and anaesthesia occurred with 15.9 and 53.0 mg L−1 eugenol, respectively. The total ammonia was significantly higher in the control group than the sedated group 7 h after transportation. Blood glucose levels were significantly higher in the sedated fish in relation to the control group 7 h after transportation. The gill histopathology analysis and muscle glycogen levels were not influenced by eugenol or the time of transportation. It is concluded that 15.9 and 53.0 mg L−1 eugenol were effective concentrations for sedation and anaesthesia in juveniles, and that 15.9 mg L−1 eugenol has the potential to be used for the transportation of freshwater angelfish for up to 7 h.

Muscle glycogen level and occurrence of acid meat in commercial hybrid pigs are regulated by two low-frequency causal variants with large effects and multiple common variants with small effects

BackgroundMeat production from the commercial crossbred Duroc × (Landrace × Yorkshire) (DLY) pig is predominant in the pork industry, but its meat quality is often impaired by low ultimate pH (pHu). Muscle glycogen level at slaughter is closely associated with pHu and meat technological quality, but its genetic basis remains elusive. The aim of this study was to identify genes and/or causative mutations associated with muscle glycogen level and other meat quality traits by performing a genome-wide association study (GWAS) and additional analyses in a population of 610 DLY pigs.ResultsOur initial GWAS identified a genome-wide significant (P = 2.54e−11) quantitative trait locus (QTL) on SSC15 (SSC for Sus scrofa chromosome) for the level of residual glycogen and glucose (RG) in the longissimus muscle at 45 min post-mortem. Then, we demonstrated that a low-frequency (minor allele frequency = 0.014) R200Q missense mutation in the PRKAG3 (RN) gene caused this major QTL effect on RG. Moreover, we showed that the 200Q (RN–) allele was introgressed from the Hampshire breed into more than one of the parental breeds of the DLY pigs. After conditioning on R200Q, re-association analysis revealed three additional QTL for RG on SSC3 and 4, and on an unmapped scaffold (AEMK02000452.1). The SSC3 QTL was most likely caused by a splice mutation (g.8283C>A) in the PHKG1 gene that we had previously identified. Based on functional annotation, the genes TMCO1 on SSC4 and CKB on the scaffold represent promising candidate genes for the other two QTL. There were significant interaction effects of the GWAS tag SNPs at those two loci with PRKAG3 R200Q on RG. In addition, a number of common variants with potentially smaller effects on RG (P < 10−4) were uncovered by a second conditional GWAS after adjusting for the two causal SNPs, R200Q and g.8283C>A.ConclusionsWe found that the RN– allele segregates in the parental lines of our DLY population and strongly influences its meat quality. Our findings also indicate that the genetic basis of RG in DLY can be mainly attributed to two major genes (PRKAG3 and PHKG1), along with many minor genes.