INTRODUCTION: Ageing skeletal muscles become both insulin resistant and atrophic. The hormone glucagon-like peptide 1 (GLP-1) facilitates postprandial glucose uptake as well as augmenting muscle perfusion, independent of insulin action. We thus hypothesized exogenous GLP-1 infusions would enhance muscle perfusion and positively affect glucose metabolism during fed-state clamps in older people. METHODS: Eight men (71 ± 1 years) were studied in a randomized crossover trial. Basal blood samples were taken before postprandial (fed-state) insulin and glucose clamps, accompanied by amino acid infusions, for 3 hours. Reflecting this, following insertions of peripheral and femoral vessels cannulae and baseline measurements, peripheral IV infusions of octreotide, insulin (Actrapid), 20% glucose, and mixed amino acids; Vamin 14-EF with or without a femoral arterial GLP-1 infusion were started. GLP-1, insulin, and C-peptide were measured by ELISA. Muscle microvascular blood flow was assessed via contrast enhanced ultrasound. Whole-body glucose handling was assayed by assessing glucose infusion rate parameters. RESULTS: Skeletal muscle microvascular blood flow significantly increased in response to GLP-1 vs feeding alone (5.0 ± 2.1 vs 1.9 ± 0.7 fold-change from basal, respectively; P = 0.008), while also increasing whole-body glucose uptake (area under the curve 16.9 ± 1.7 vs 11.4 ± 1.8 mg/kg-1/180 minutes-1, P = 0.02 ± GLP, respectively). CONCLUSIONS: The beneficial effects of GLP-1 on whole-body glycemic control are evident with insulin clamped at fed-state levels. GLP-1 further enhances the effects of insulin on whole-body glucose uptake in older men, underlining its role as a therapeutic target. The effects of GLP-1 in enhancing microvascular flow likely also affects other glucose-regulatory organs, reflected by greater whole-body glucose uptake.

• Klíčová slova
• extrapancreatic effects, glucagon like peptide 1, microcirculation, microvascular blood flow, microvascular recruitment, muscle glucose metabolism, muscle glucose uptake,
• MeSH
• glukagonu podobný peptid 1 * metabolismus   MeSH
• glukosa metabolismus   MeSH
• inzulin * metabolismus   MeSH
• kosterní svaly metabolismus   MeSH
• krevní glukóza metabolismus   MeSH
• lidé MeSH
• oktreotid farmakologie   MeSH
• perfuze MeSH
• senioři MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• randomizované kontrolované studie MeSH
• Názvy látek
• glukagonu podobný peptid 1 * MeSH
• glukosa MeSH
• inzulin * MeSH
• krevní glukóza MeSH
• oktreotid MeSH

CONTEXT: Insulin resistance (IR) and obesity differ among ethnic groups in Singapore, with the Malays more obese yet less IR than Asian-Indians. However, the molecular basis underlying these differences is not clear. OBJECTIVE: As the skeletal muscle (SM) is metabolically relevant to IR, we investigated molecular pathways in SM that are associated with ethnic differences in IR, obesity, and related traits. DESIGN, SETTING, AND MAIN OUTCOME MEASURES: We integrated transcriptomic, genomic, and phenotypic analyses in 156 healthy subjects representing three major ethnicities in the Singapore Adult Metabolism Study. PATIENTS: This study contains Chinese (n = 63), Malay (n = 51), and Asian-Indian (n = 42) men, aged 21 to 40 years, without systemic diseases. RESULTS: We found remarkable diversity in the SM transcriptome among the three ethnicities, with >8000 differentially expressed genes (40% of all genes expressed in SM). Comparison with blood transcriptome from a separate Singaporean cohort showed that >95% of SM expression differences among ethnicities were unique to SM. We identified a network of 46 genes that were specifically downregulated in Malays, suggesting dysregulation of components of cellular respiration in SM of Malay individuals. We also report 28 differentially expressed gene clusters, four of which were also enriched for genes that were found in genome-wide association studies of metabolic traits and disease and correlated with variation in IR, obesity, and related traits. CONCLUSION: We identified extensive gene-expression changes in SM among the three Singaporean ethnicities and report specific genes and molecular pathways that might underpin and explain the differences in IR among these ethnic groups.

• MeSH
• celogenomová asociační studie MeSH
• dospělí MeSH
• etnicita genetika   MeSH
• index tělesné hmotnosti MeSH
• inzulinová rezistence etnologie   genetika   MeSH
• kohortové studie MeSH
• kosterní svaly metabolismus   MeSH
• lidé MeSH
• mladý dospělý MeSH
• signální transdukce genetika   MeSH
• stanovení celkové genové exprese MeSH
• transkriptom * MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Geografické názvy
• Singapur MeSH

To investigate the potential of eland for meat production, the yield, physical quality and chemical composition of seven muscles were characterized from both male (n = 6) and female (n = 6) carcasses. Although carcass weights did not differ, cows had greater biceps femoris (BF), semitendinosus (ST) and supraspinatus (SS) muscle yields. The semimembranosus (SM) from cows had the greatest drip loss and were more yellow (b*) than all muscles evaluated from both sexes. Shear force measurements showed no effect of sex but large variations between muscles existed (65.5 to 97.6 N). Moisture content was greater within the BF, SS, ST and infraspinatus (IS) than the longissimus thoracis et lumborum (LTL) and SM. The LTL and IS had the lowest intramuscular fat content, while the LTL and SM muscle had the highest crude protein content. Sex had little effect on eland meat composition, showing potential for the meat of both sexes to be marketed as a lean meat source.

• Klíčová slova
• Antelope, Colour, Muscle profiling, Tenderness, Venison, pH,
• MeSH
• antilopy * MeSH
• barva MeSH
• kosterní svaly anatomie a histologie   chemie   MeSH
• lipidy analýza   MeSH
• maso analýza   MeSH
• pevnost ve smyku MeSH
• sexuální faktory MeSH
• svalové proteiny analýza   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• lipidy MeSH
• svalové proteiny MeSH

We tested whether treatment with exogenous L-arginine, the precursor of nitric oxide (NO), could protect the skeletal muscle from ischemia/reperfusion (I/R) injury. A rabbit hindlimb I/R model (2.5 h ischemia/2 h reperfusion) was used. Morphological changes were elucidated by morphometry. Plasma concentrations of malondialdehyde (pMDA), as well as L-arginine and L-citrulline content in the plasma and skeletal muscle were measured. I/R injury in the skeletal muscle was manifested by development of prominent interstitial edema (fraction of interfiber area was 26.23% vs 15.09% in sham operated control, p < .005) and severe microvascular constriction (capillary area was 11.41 microns2 vs 16.92 in control, p <.005). These changes were accompanied by increased pMDA levels, indicating a process of lipid peroxidation in the cell membranes. L-arginine treatment (4 mg/kg/min intravenously, for 1 h, infusion initiated 30 min before reperfusion) caused an intracellular accumulation of this amino acid in the SM. Intracellular concentrations of L-citrulline increased (201.0 mumol/dm3 after reperfusion vs 176.0 before ischemia onset, p < .005), suggesting stimulated endogenous NO synthesis. L-arginine treatment protected capillary constriction (capillary area was 17.64 microns2 vs 11.41 in the untreated animals, p < .0005) and reduced interstitial edema after reperfusion (fraction of interfiber area was 17.80% vs 26.23 in untreated animals, p < 0.005). The protective effect of L-arginine treatment on I/R injury of SM may be related to its ability to prevent microvascular constriction and reduce permeability disorders by the stimulation of endogenous NO production.

• MeSH
• arginin metabolismus   terapeutické užití   MeSH
• kosterní svaly krevní zásobení   metabolismus   patologie   MeSH
• králíci MeSH
• reperfuzní poškození farmakoterapie   metabolismus   patologie   MeSH
• zadní končetina krevní zásobení   MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• arginin MeSH

Sulfur mustard (SM) is a chemical warfare agent with cytotoxic effect and a tight link to oxidative stress (OS). Depletion of antioxidants is considered as a cause of detrimental consequence and belongs to the important steps leading to cell death. The oxidative injury appearing after SM exposure is not well understood. Nevertheless, identification of the pathological processes would be a good opportunity to establish an efficient therapy. Here, we focused our effort on an estimation of reactive oxygen species homeostasis and apoptotic processes in Wistar rats exposed to 0-160 mg/kg of SM. We assayed antioxidant activity, thiobarbituric acid reactive substances, reduced glutathione/oxidized glutathione, metallothionein, glutathione reductase, glutathione peroxidase, glutathione S-transferase, caspase 3, and glucose in the livers, kidneys, and muscles of the animals. Significant OS, depletion of low-molecular-mass antioxidants, increase in caspase activity, and some other processes related to SM action were determined. Moreover, we infer a principal role of OS in the tested organs.

• MeSH
• antioxidancia metabolismus   MeSH
• chemické bojové látky toxicita   MeSH
• glutathion metabolismus   MeSH
• játra účinky léků   MeSH
• kosterní svaly účinky léků   MeSH
• krysa rodu Rattus MeSH
• látky reagující s kyselinou thiobarbiturovou metabolismus   MeSH
• ledviny účinky léků   MeSH
• oxidační stres účinky léků   MeSH
• oxidoreduktasy metabolismus   MeSH
• potkani Wistar MeSH
• yperit toxicita   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antioxidancia MeSH
• chemické bojové látky MeSH
• glutathion MeSH
• látky reagující s kyselinou thiobarbiturovou MeSH
• oxidoreduktasy MeSH
• yperit MeSH

BACKGROUND/OBJECTIVES: Branched chain amino acids (BCAA) are among nutrients strongly linked with insulin sensitivity (IS) measures. We investigated the effects of a chronic increase of BCAA intake on IS in two groups of healthy subjects differing in their basal consumption of BCAA, that is, vegans and omnivores. SUBJECTS/METHODS: Eight vegans and eight matched omnivores (five men and three women in each group) received 15 g (women) or 20 g (men) of BCAA daily for 3 months. Anthropometry, blood analyses, glucose clamp, arginine test, subcutaneous abdominal adipose tissue (AT) and skeletal muscle (SM) biopsies (mRNA levels of selected metabolic markers, respiratory chain (RC) activity) were performed at baseline, after the intervention and after a 6 month wash-out period. RESULTS: Compared with omnivores, vegans had higher IS at baseline (GIR, glucose infusion rate: 9.6±2.4 vs 7.1±2.4 mg/kg/min, 95% CI for difference: 0.55 to 5.82) that declined after the intervention and returned to baseline values after the wash-out period (changes in GIR with 95% CI, 3-0 months: -1.64 [-2.5; -0.75] and 9-3 months: 1.65 [0.75; 2.54] mg/kg/min). No such change was observed in omnivores. In omnivores the intervention led to an increased expression of lipogenic genes (DGAT2, FASN, PPARγ, SCD1) in AT. SM RC activity increased in both groups. CONCLUSIONS: Negative impact of increased BCAA intake on IS was only detected in vegans, that is, subjects with low basal amino acids/BCAA intake, which appear to be unable to induce sufficient compensatory changes within AT and SM on a BCAA challenge.

• MeSH
• antropometrie MeSH
• cvičení MeSH
• dieta veganská MeSH
• dieta MeSH
• dietární expozice škodlivé účinky   MeSH
• dietní proteiny aplikace a dávkování   MeSH
• dospělí MeSH
• glykemický clamp MeSH
• inzulin krev   MeSH
• inzulinová rezistence MeSH
• kosterní svaly účinky léků   metabolismus   MeSH
• krevní glukóza metabolismus   MeSH
• lidé MeSH
• mladý dospělý MeSH
• prospektivní studie MeSH
• průzkumy a dotazníky MeSH
• vegani * MeSH
• větvené aminokyseliny aplikace a dávkování   krev   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• dietní proteiny MeSH
• inzulin MeSH
• krevní glukóza MeSH
• větvené aminokyseliny MeSH

Using continuous-wave near-infrared spectroscopy (NIRS), this study compared three different methods, namely the slope method (SM), the amplitude method (AM), and the area under the curve (AUC) method to determine the variations of intramuscular oxygenation level as a function of workload. Ten right-handed subjects (22+/-4 years) performed one isometric contraction at each of three different workloads (30 %, 50 % and 90 % of maximal voluntary strength) during a period of twenty seconds. Changes in oxyhemoglobin (delta[HbO(2)]) and deoxyhemoglobin (delta[HHb]) concentrations in the superficial flexor of fingers were recorded using continuous-wave NIRS. The results showed a strong consistency between the three methods, with standardized Cronbach alphas of 0.87 for delta[HHb] and 0.95 for delta[HbO(2)]. No significant differences between the three methods were observed concerning delta[HHb] as a function of workload. However, only the SM showed sufficient sensitivity to detect a significant decrease in delta[HbO(2)] between 30 % and 50 % of workload (p<0.01). Among these three methods, the SM appeared to be the only method that was well adapted and sensitive enough to determine slight changes in delta[HbO(2)]. Theoretical and methodological implications of these results are discussed.

• MeSH
• biologické markery krev   MeSH
• blízká infračervená spektroskopie metody   MeSH
• cvičení fyziologie   MeSH
• dospělí MeSH
• hemoglobiny metabolismus   MeSH
• isometrická kontrakce * MeSH
• kosterní svaly metabolismus   MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• oxyhemoglobiny metabolismus   MeSH
• plocha pod křivkou MeSH
• prediktivní hodnota testů MeSH
• reprodukovatelnost výsledků MeSH
• ROC křivka MeSH
• spotřeba kyslíku * MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Názvy látek
• biologické markery MeSH
• deoxyhemoglobin MeSH Prohlížeč
• hemoglobiny MeSH
• oxyhemoglobiny MeSH

The urea concentration in the renal cortex ([RC]) of pentobarbital-anaesthetized dogs was 5.71 times higher than the plasma concentration ([P]); the liver ([L]) and the skeletal muscle ([SM]) concentrations were the same as ([P]). Rapid infusion of 20% urea (1 g/kg b.w. within 1 min) was followed by a sudden increase in [P]; [RC] and [L] rose to values nonsignificantly different from [P] and remained non-significantly different for the whole 4 hours of the experiment; at the end, [P] was still about 10 times higher than before infusion. Surprisingly, [SM] 2 and 6 min after infusion was significantly lower than [P]; later they were the same. The experiment thus does not testify to the existence of active transport of urea in the RC. The permeability of the skeletal muscle membrane for urea is lower than that of the RC and liver. Chronic uraemia was induced in rats by transplanting the trigonum vesicae into the peritoneal cavity. In addition to the chemical determination of urea, 14C-urea (marked*) was also measured. [RC]/[P] and [RC*]/[P*] fell as [P] rose; [L], [L*] [SM] and [SM*] never differed from [P] or [P*]. Fluid [PF] collected in the peritoneal cavity had the same chemically determined and radioactive urea concentration as P, but it was hypoosmolar and had a lower [Na+] than P. These experiments likewise did not testify to active urea transport in the RC. It is not clear what caused the osmolarity and sodium gradient between the PF and P, but the peritoneal wall definitely did not act as a simple dialyzing membrane.

• MeSH
• biologický transport MeSH
• extracelulární prostor metabolismus   MeSH
• inbrední kmeny potkanů MeSH
• játra metabolismus   MeSH
• kinetika MeSH
• krysa rodu Rattus MeSH
• kůra ledviny metabolismus   MeSH
• močovina krev   metabolismus   MeSH
• osmolární koncentrace MeSH
• peritoneum MeSH
• psi MeSH
• sodík metabolismus   MeSH
• svaly metabolismus   MeSH
• tkáňová distribuce MeSH
• uremie metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• psi MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• močovina MeSH
• sodík MeSH

OBJECTIVE: We previously demonstrated that the handle-region peptide, a prorenin/renin receptor [(P)RR] blocker, reduces body weight and fat mass and may improve insulin sensitivity in high-fat fed mice. We hypothesized that knocking out the adipose tissue (P)RR gene would prevent weight gain and insulin resistance. METHODS: An adipose tissue-specific (P)RR knockout (KO) mouse was created by Cre-loxP technology using AP2-Cre recombinase mice. Because the (P)RR gene is located on the X chromosome, hemizygous males were complete KO and had a more pronounced phenotype on a normal diet (ND) diet compared to heterozygous KO females. Therefore, we challenged the female mice with a high-fat diet (HFD) to uncover certain phenotypes. Mice were maintained on either diet for 9 weeks. RESULTS: KO mice had lower body weights compared to wild-types (WT). Only hemizygous male KO mice presented with lower total fat mass, higher total lean mass as well as smaller adipocytes compared to WT mice. Although food intake was similar between genotypes, locomotor activity during the active period was increased in both male and female KO mice. Interestingly, only male KO mice had increased O2 consumption and CO2 production during the entire 24-hour period, suggesting an increased basal metabolic rate. Although glycemia during a glucose tolerance test was similar, KO males as well as HFD-fed females had lower plasma insulin and C-peptide levels compared to WT mice, suggesting improved insulin sensitivity. Remarkably, all KO animals exhibited higher circulating adiponectin levels, suggesting that this phenotype can occur even in the absence of a significant reduction in adipose tissue weight, as observed in females and, thus, may be a specific effect related to the (P)RR. CONCLUSIONS: (P)RR may be an important therapeutic target for the treatment of obesity and its associated complications such as type 2 diabetes.

• Klíčová slova
• (P)RR, prorenin/renin receptor, (Pro)renin receptor, ANG, Angiotensin, Adipose tissue, Adipose tissue knock-out mice, BAT, brown adipose tissue, BB, beam break, HACT, horizontal activity, HFD, high-fat diet, HRP, handle-region peptide, Insulin resistance, KO, knock-out, ND, normal diet, OGTT, oral glucose tolerance test, Obesity, PGF, perigonadal fat, PPAR-γ, peroxisome proliferator-activated receptor-γ, PRA, plasma renin activity, PRF, perirenal fat, RAS, renin-angiotensin system, Renin-angiotensin system, SE, standard error, SFC, abdominal subcutaneous fat, SM, skeletal muscle, SMG, submandibular gland, TG, triglycerides, V-ATPase, vacuolar proton pump H+-ATPase, VCO2, carbon dioxide production, VO2, oxygen consumption, WT, wild-type,
• Publikační typ
• časopisecké články MeSH

Background: To date, no study has focused on body composition characteristics and on parameters associated with skeletal muscle damage and renal function in runners participating in a 24-h winter race held under extremely cold environmental conditions (average temperature of -14.3°C). Methods: Anthropometric characteristics, plasma urea (PU), plasma creatinine (Pcr), creatine kinase (CK), plasma volume (PV) and total body water (TBW) were assessed pre- and post-race in 20 finishers (14 men and 6 women). Results: In male runners, body mass (BM) (p = 0.003) and body fat (BF) (p = 0.001) decreased [-1.1 kg (-1.4%) and -1.1 kg (-13.4%), respectively]; skeletal muscle mass (SM) and TBW remained stable (p > 0.05). In female runners, BF decreased (p = 0.036) [-1.3 kg (-7.8%)] while BM, SM and TBW remained stable (p > 0.05). The change (Δ) in BM was not related to Δ BF; however, Δ BM was related to Δ SM [r = 0.58, p = 0.007] and Δ TBW (r = 0.59, p = 0.007). Δ SM correlated with Δ TBW (r = 0.51, p = 0.021). Moreover, Δ BF was negatively associated with Δ SM (r = -0.65, p = 0.002). PV (p < 0.001), CK (p < 0.001), Pcr (p = 0.004) and PU (p < 0.001) increased and creatinine clearance (CrCl) decreased (p = 0.002). The decrease in BM was negatively related to the increase in CK (r = -0.71, p < 0.001). Δ Pcr was positively related to Δ PU (r = 0.64, p = 0.002). The decrease in CrCl was negatively associated with the increase in both PU (r = -0.72, p < 0.001) and CK (r = -0.48, p = 0.032). Conclusion: The 24-h running race under extremely cold conditions led to a significant BF decrease, whereas SM and TBW remained stable in both males and females. Nevertheless, the increase in CK, Pcr and PU was related to the damage of SM with transient impaired renal function.

• Klíčová slova
• 24 h, body composition, extreme weather conditions, ultra-running, winter,
• Publikační typ
• časopisecké články MeSH