A metabolomics study: Reveals the protective effect and mechanism of Terminalia chebula Retz on the cardiotoxicity induced by radix Aconiti kusnezoffii Reichb.

To reveal the protective effect of Terminalia chebula Retz (TCR) on cardiotoxicity induced by radix of Aconitum kusnezoffii Reichb (AKR). Control, AKR, AKR-TCR 1:3, AKR-TCR 1:1, AKR-TCR 3:1 and TCR-prepared AKR groups were set up. After treatment, the heart tissues were observed by H&E staining and transmission electron microscope. Serum myoglobin (MB) and troponin (cTn) were detected by ELISA. UPLC-Q Exactive/MS analysis was performed to detect the metabolic difference among the groups. ELISA results showed that the MB and cTn values of AKR group were significantly higher than Control group (P<0.05), while those of the other groups were lower than AKR group. TCR-prepared AKR group had similar MB and cTn contents to the Control group. Histopathological examination also indicated better detoxifying effects in the TCR-prepared AKR and AKR-TCR 1:1 group. The serum metabolomics analysis showed obvious distinction between the AKR and Control groups, while AKR-TCR combination reversed the metabolomics changes induced by AKR. Through multivariate statistical analysis, 9 metabolic markers related to energy, nucleic acid and amino acid metabolism were identified. Conclusively, AKR-induced cardiotoxicity may be related to energy, nucleic acid and amino acid metabolism, and TCR can reduce the cardiotoxicity by regulating the relative metabolism pathways.

Self-Assembled Manganese(I)-Based Selenolato-Bridged Tetranuclear Metallorectangles: Host-Guest Interaction, Anticancer, and CO-Releasing Studies.

Supramolecular one-step self-assembly of dimanganese decacarbonyl, diaryl diselenide, and linear dipyridyl ligands (L = pyrazine (pz), 4,4'-bipyridine (bpy), and trans-1,2-bis(4-pyridyl)ethylene (bpe)) has resulted in the formation of selenolato-bridged manganese(I)-based metallorectangles. The synthesis of tetranuclear Mn(I)-based metallorectangles [{(CO)3Mn(µ-SeR)2Mn(CO)3}2(µ-L)2] (1-6) was facilitated by the oxidative addition of diaryl diselenide to dimanganese decacarbonyl with the simultaneous coordination of linear bidentate pyridyl linker in an orthogonal fashion. Formation of metallorectangles 1-6 was ascertained using IR, UV-vis, NMR spectroscopic techniques, and elemental analyses. The molecular mass of compounds 2, 4, and 6 were determined by ESI-mass spectrometry. Solid-state structural elucidation of 2, 3, and 6 by single-crystal X-ray diffraction methods revealed a rectangular framework wherein selenolato-bridges and pyridyl ligands define the shorter and longer edges, respectively. Also, the guest binding capability of metallorectangles 3 and 5 with different aromatic guests was studied using UV-vis absorption and emission spectrophotometric titration methods that affirmed strong host-guest binding interactions. The formation of the host-guest complex between metallorectangle 3 and pyrene has been explicitly corroborated by the single-crystal X-ray structure of 3•pyrene. Moreover, select metallorectangles 1-4 and 6 were studied to explore their anticancer activity, while CO-releasing ability of metallorectangle 2 was further appraised using equine heart myoglobin assay.

Comparative study of the influence of hawthorn (Crataegus monogyna) berry ethanolic extract and butylated hydroxylanisole (BHA) on lipid peroxidation, myoglobin oxidation, consistency and firmness of minced pork during refrigeration.

BACKGROUND: Following public concern on the use of synthetic food antioxidants, there is an increasing demand for the application of mixed or purified natural antioxidants to maintain quality of meat products quality during storage. The aim of this research was to investigate the effect of ethanolic extract of hawthorn berry, compared to butylated hydroxylanisole (BHA), on lipid peroxidation, myoglobin oxidation, protein electrophoresis pattern, consistency and firmness of minced pork during refrigeration at 4 °C, and to identify the relationship between chemical modifications and consistency variation. RESULTS: After 6 days of refrigeration it was found that the thiobarbituric acid reactive substances value of minced pork containing 200 mg GAE kg-1 total phenolics in minced meat (200 HP) was significantly lower (0.1543 ± 0.006 mg) compared to BHA-treated meat. The ratio of oxymyoglobin to metmyoglobin in treated minced pork was respectively 0.845 for 200 HP and 0.473 for BHA-treated minced meat. Concentrations of 100 HP or 300 HP will generate statistically higher firmness than BHA in minced pork. CONCLUSION: Hawthorn berry ethanolic extract was more effective than BHA in reducing lipid oxidation and protein degradation, for maintaining firmness and consistency of minced pork during 6 days of refrigeration at 4 °C. © 2017 Society of Chemical Industry.

Iron restriction increases myoglobin gene and protein expression in Soleus muscle of rats.

Iron is an important trace element for proper cell functioning. It is present in cytochromes, hemoglobin and myoglobin (Mb), where it binds to oxygen. It is also an electron acceptor in the respiratory chain. Mb is an 18 kDa heme-protein, highly expressed in skeletal muscle and heart. The expression of several genes involved in the metabolism of iron is post-transcriptionally regulated by this element. Iron was shown to interfere with the polyadenylation step, modifying their poly (A) tail length and, as a consequence, their stability and translation rate. The aim of this study was to investigate whether iron supplementation or long and short-term restriction affects Mb gene and protein expression, as well as Mb mRNA poly(A) tail length, in cardiac and skeletal muscles of rats. Long-term iron restriction caused an increase in Mb gene and protein expression in Soleus muscle. No changes were observed in extensor digitorum longus muscle and heart. Short-term iron supplementation after iron deprivation did not alter Mb gene expression and mRNA poly(A) tail length in all tissues studied. These results indicate that Mb gene and protein expression is upregulated in response to iron deprivation, an effect that is tissue-specific and seems to occur at transcriptional level.

Specific macrophage subtypes influence the progression of rhabdomyolysis-induced kidney injury.

Rhabdomyolysis can be life threatening if complicated by AKI. Macrophage infiltration has been observed in rat kidneys after glycerol-induced rhabdomyolysis, but the role of macrophages in rhabdomyolysis-induced AKI remains unknown. Here, in a patient diagnosed with rhabdomyolysis, we detected substantial macrophage infiltration in the kidney. In a mouse model of rhabdomyolysis-induced AKI, diverse renal macrophage phenotypes were observed depending on the stage of the disease. Two days after rhabdomyolysis, F4/80(low)CD11b(high)Ly6b(high)CD206(low) kidney macrophages were dominant, whereas by day 8, F4/80(high)CD11b(+)Ly6b(low)CD206(high) cells became the most abundant. Single-cell gene expression analyses of FACS-sorted macrophages revealed that these subpopulations were heterogeneous and that individual cells simultaneously expressed both M1 and M2 markers. Liposomal clodronate-mediated macrophage depletion significantly reduced the early infiltration of F4/80(low)CD11b(high)Ly6b(high)CD206(low) macrophages. Furthermore, transcriptionally regulated targets potentially involved in disease progression, including fibronectin, collagen III, and chemoattractants that were identified via single-cell analysis, were verified as macrophage-dependent in situ. In vitro, myoglobin treatment induced proximal tubular cells to secrete chemoattractants and macrophages to express proinflammatory markers. At day 30, liposomal clodronate-mediated macrophage depletion reduced fibrosis and improved both kidney repair and mouse survival. Seven months after rhabdomyolysis, histologic lesions were still present but were substantially reduced with prior depletion of macrophages. These results suggest an important role for macrophages in rhabdomyolysis-induced AKI progression and advocate the utility of long-term follow-up for patients with this disease.

Allopurinol prevents cardiac and skeletal muscle damage in professional soccer players.

Xanthine oxidase (XO), a free radical-generating enzyme, is involved in tissue damage produced during exhaustive exercise. Our aim was to test whether allopurinol, a powerful inhibitor of XO, may be effective in preventing exercise-induced tissue damage in soccer players. Twelve soccer players were randomized into two experimental groups. One received allopurinol, before a match of the premier Spanish Football League, and the other placebo. Allopurinol prevented the exercise-induced increase in all the markers of skeletal muscle damage analyzed: creatine kinase, lactate dehydrogenase, aspartate aminotransferase, and myoglobin. Creatine kinase-MB isoenzyme and highly sensitive troponin T, specific biomarkers of myocardial injury, increased significantly in the placebo but not in the allopurinol-treated group after the football match. We also found that the exercise-induced lipid peroxidation, as reflected by malondialdehyde measurements, was prevented after allopurinol administration. However, inhibition of XO did not prevent the increment in the activity of alanine aminotransferase found after the match. No changes in the serum gamma glutamyltransferase activity was found after the match on either the placebo and the allopurinol groups. These two enzymes were determined as biomarkers of liver injury. Allopurinol represents an effective and inexpensive pharmacological agent to prevent tissue damage in soccer players.

Crystallographic studies with xenon and nitrous oxide provide evidence for protein-dependent processes in the mechanisms of general anesthesia.

BACKGROUND: The mechanisms by which general anesthetics, including xenon and nitrous oxide, act are only beginning to be discovered. However, structural approaches revealed weak but specific protein-gas interactions. METHODS: To improve knowledge, we performed x-ray crystallography studies under xenon and nitrous oxide pressure in a series of 10 binding sites within four proteins. RESULTS: Whatever the pressure, we show (1) hydrophobicity of the gas binding sites has a screening effect on xenon and nitrous oxide binding, with a threshold value of 83% beyond which and below which xenon and nitrous oxide, respectively, binds to their sites preferentially compared to each other; (2) xenon and nitrous oxide occupancies are significantly correlated respectively to the product and the ratio of hydrophobicity by volume, indicating that hydrophobicity and volume are binding parameters that complement and oppose each other's effects; and (3) the ratio of occupancy of xenon to nitrous oxide is significantly correlated to hydrophobicity of their binding sites. CONCLUSIONS: These data demonstrate that xenon and nitrous oxide obey different binding mechanisms, a finding that argues against all unitary hypotheses of narcosis and anesthesia, and indicate that the Meyer-Overton rule of a high correlation between anesthetic potency and solubility in lipids of general anesthetics is often overinterpreted. This study provides evidence that the mechanisms of gas binding to proteins and therefore of general anesthesia should be considered as the result of a fully reversible interaction between a drug ligand and a receptor as this occurs in classical pharmacology.

Effect of whey protein- and carbohydrate-enriched diet on glycogen resynthesis during the first 48 h after a soccer game.

The effect of a whey protein- and carbohydrate (CHO)-enriched diet on the rate of muscle glycogen resynthesis after a soccer match was examined. Sixteen elite soccer players were randomly assigned to a group ingesting a diet rich in carbohydrates and whey protein [CHO, protein, and fat content was 71, 21, and 8E%, respectively; high content of carbohydrates and whey protein (HCP), n = 9] or a group ingesting a normal diet (55, 18, and 26E%; control [CON], n = 7) during a 48-h recovery period after a soccer match. CON and three additional players carried out a 90- and 60-min simulated match without body contacts (SIM90 and SIM60). Muscle glycogen was lowered (P < 0.05) by 54, 48, 53, and 38% after the matches in CON, HCP, SIM90, and SIM60, respectively. Glycogen resynthesis during the first 48 h after the match was not different between CON and HCP, whereas glycogen resynthesis was slower (P < 0.05) during the first 24 h after SIM60 than SIM90 (2.88 ± 0.84 vs 4.32 ± 0.54 mmol/kg dw/h). In HCP, glycogen content in type II muscle fibers was still lowered 48 h after the match. In conclusion, glycogen resynthesis 48 h after a soccer match is not elevated by ingestion of a HCP diet. Furthermore, glycogen resynthesis does not appear to be impaired by body contacts during a match.

Effects of pyruvate on lipid oxidation and ground beef color.

UNLABELLED: Our overall objective was to better understand the effects of added pyruvate on enhanced beef color stability. The 2 possible mechanisms assessed were the role of pyruvate in lipid oxidation and direct interaction between pyruvate and beef myoglobin. Microsomes were incubated with pyruvate at pH 5.6, 25 °C, and lipid oxidation was measured hourly for 3 h. Bovine oxymyoglobin at pH 5.6 was incubated with pyruvate and used to quantify both redox stability (metmyoglobin formation) and pyruvate-myoglobin adduction using mass spectrometry analysis. Surface color and lipid oxidation were measured on ground beef patties stored for 6 d in polyvinyl chloride over-wrap (PVC) or high oxygen. Addition of pyruvate to microsomes decreased lipid oxidation compared with controls (P < 0.05). Conversely, no effect on myoglobin was observed (no changes in redox stability and no peaks corresponding to pyruvate were observed; P > 0.05). However, pyruvate increased color stability and decreased lipid oxidation of ground beef patties packaged in PVC and high oxygen. Pyruvate decreased nitric oxide metmyoglobin-reducing capacity and oxygen consumption of patties compared with controls (P < 0.05). This research suggests that pyruvate may improve beef color stability primarily through its antioxidant effect on lipids. PRACTICAL APPLICATION: Discoloration of meat often results in significant revenue loss. This study suggests that pyruvate can improve the color stability of patties packaged in high oxygen and PVC primarily through its antioxidant effect on lipids.

Protective effect of dimethyl sulfoxide on acute myocardial infarction in rats.

Dimethyl sulfoxide (DMSO) is an organic compound widely used as solvent in biological studies and as vehicle for drug administration. DMSO has been shown to possess several biological effects, including antioxidant, anti-inflammatory, antinociceptive effects, and it has been proposed to be therapeutic in several disorders, such as gastrointestinal diseases, rheumatologic diseases, and for the treatment of several manifestations of amyloidosis. To better define the biological profile of DMSO, we investigated its effect on an in vivo model of acute myocardial infarction in rats, caused by left anterior descending coronary artery ligation. Our results show that pretreatment of rats with intraperitoneal (ip) DMSO (500 microL/Kg) for 3 consecutive days before left anterior descending coronary artery ligation significantly (P < 0.05) reduced cardiac damage from 18.75 +/- 4.88% (n = 12) to 4.46 +/- 2.01% (n = 8); serum levels of troponin I from 29.35 +/- 12.32 ng/mL (n = 8) to 2.95 +/- 1.32 ng/mL (n = 4); and serum levels of myoglobin from 46.86 +/- 10.35 ng/mL (n = 7) to 13.75 +/- 0.85 ng/mL (n = 4). Our data demonstrate that DMSO has a protective effect in a model of acute myocardial infarction in rats.

Effect of chelating agents and spice-derived antioxidants on myoglobin oxidation in a lipid-free model system.

This study compared myoglobin (Mb) oxidation in lipid-free model systems containing iron and Type I (radical quenching) or Type II (metal chelating) antioxidants. Oxidation was measured as loss of oxymyoglobin (MbO(2)) during 0 to 24 h holding at 22 degrees C. Sodium tripolyphosphate (STPP) demonstrated iron-binding ability at all concentrations tested (88% and 21% added iron bound at 1 and 0.05 mg/mL, respectively). Iron chelation was observed for phytic acid only at the highest concentration (9.5% bound at 1 mg/mL phytate). Neither Type I antioxidant (rosmarinate or eugenol) demonstrated any iron chelating ability (<0.5% bound). In presence of iron, Type I antioxidants had a significant (P < 0.05) prooxidant effect (54.7% retention of MbO(2) in control, 9.5% and 37.5% retention in rosmarinate and eugenol samples, respectively). The Type II antioxidants (STPP and phytate) were more effective inhibitors (P < 0.05) of Mb oxidation than Type I antioxidants, (68.7% and 61.1% for STPP and phytate, respectively). Type I antioxidants were capable of rapid reduction of ferric iron to the ferrous form, as measured by the ferrozine assay. This strong reducing ability accounted for the prooxidant effects of rosmarinic acid and eugenol, since ferrous iron is the form associated with generation of oxygen radicals, and subsequent Mb oxidation. Type II antioxidants chelated and thus prevented the oxidizing effect of added ferrous iron. Mb oxidation can proceed rapidly (within 15 min) in the presence of iron and the absence of lipid, especially if reducing compounds such as rosmarinic acid or eugenol are also present to maintain iron in an active ferrous form.

Entropic stabilization of myoglobin by subdenaturing concentrations of guanidine hydrochloride.

To find out the changes in the internal dynamics and function of proteins as a consequence of their binding interactions with guanidine hydrochloride (GdnHCl), laser flash photolysis and optical absorption methods have been used to study the dynamic events in the horse myoglobin-CO complex (MbCO) in the presence of subdenaturing concentrations of GdnHCl at pH 7, 22 degrees C. The rate coefficients for geminate rebinding and bimolecular rebinding (k(on)) were measured by laser photolysis of CO in MbCO, and the CO dissociation rate (k(off)) was determined by the CO replacement method using hexacyanoferrate ion or NO. Starting from the native-state condition, the values of k(on) and k(off) decrease by approximately 1.4 (+/-0.1)-fold in the presence of 0.1-0.3 M GdnHCl, and then increase at higher concentrations of the denaturant. This has been taken as evidence for internal motional constraints and increased stability of the protein in the subdenaturing region giving rise to gated entry of the photolyzed CO from the solvent. The rate for geminate rebinding does not show any decrease in the rate versus GdnHCl concentration plots. The values for the activation enthalpy for the CO dissociation reaction and the entropy loss relative to the native-state entropy, both measured as a function of GdnHCl concentration, indicate that the protein is indeed stabilized under subdenaturing conditions. Analyses of thermal unfolding transitions of myoglobin in the presence of different concentrations of GdnHCl indicate that the stability of this protein extracted from the linear free energy model is approximately 3-4 kcal mol(-1) less than the true stability. The results indicate the appropriateness of the denaturant binding model for the analysis of GdnHCl-induced unfolding data, and provide a value of 7.9 kcal mol(-1) as the true stability of the protein.

[Metformin--an inhibitor of early stages of protein glycation]. / Metformina--inhibitor wczesnych etapów glikacji bialek.

Nonenzymatic glycation of proteins is associated with the long-term diabetes complication. The aim of this work was to examine in vitro the infuence of metformin on glycated proteins formation by mass spectrometry (ESI/MS, LC/MS/MS) and spectrofluorimetric method. Obtained results suggest that metformin dose-dependently inhibits early stage of Maillard reaction, although with the weaker potency than known glycation inhibitor aminoguanidine.

Skeletal muscle capillarization and oxidative metabolism in healthy smokers.

We investigated whether the lower fatigue resistance in smokers than in nonsmokers is caused by a compromised muscle oxidative metabolism. Using calibrated histochemistry, we found no differences in succinate dehydrogenase (SDH) activity, myoglobin concentration, or capillarization in sections of the vastus lateralis muscle between smokers and nonsmokers. The relationship between fatigue resistance and SDH activity in nonsmokers (r = 0.93; p = 0.02) is absent in smokers. This indicates that the lower muscle fatigue resistance of smokers can likely be attributed to causes other than differences in oxidative metabolism and capillarization.

Effect of trehalose on W7FW14F apomyoglobin and insulin fibrillization: new insight into inhibition activity.

Trehalose, a disaccharide present in many nonmammalian species, protects cells against various environmental stresses. Trehalose has recently been shown to decrease aggregate formation and toxicity in cell models and to alleviate amyloid-induced diseases. The aim of our study was to use two amyloid-forming proteins, i.e., W7FW14F apomyoglobin and insulin, as model systems to elucidate the molecular mechanism by which trehalose affects the amyloid aggregation process and to investigate further its therapeutic potential. Protein aggregation was examined by far-UV circular dichroism, UV absorption, thioflavin T fluorescence, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, atomic force microscopy, and Fourier transform infrared spectroscopy. Cell viability was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction assay. We found that trehalose does not inhibit protein aggregation but acts at different stages of the fibrillization process depending on the protein model used. In fact, trehalose dose-dependently inhibited fibril formation in the W7FW14F apomyoglobin model and increased the lag phase in the insulin model. In both cases, trehalose caused accumulation of toxic oligomeric species. The results suggest that trehalose may favor or inhibit the formation of "on-pathway" or "off-pathway" oligomeric intermediates depending on the nature of the aggregating protein.

Warm ischemia provokes inflammation and regional hypercoagulability within the heart during off-pump coronary artery bypass: a possible target for serine protease inhibition.

OBJECTIVE: Accumulating evidence suggests that a hypercoagulable state influences early graft failure after off-pump coronary artery bypass (OPCAB). We hypothesized that regional myocardial ischemia caused by obligatory periods of coronary occlusion during OPCAB is an important trigger for this prothrombotic state. METHODS: Using a series of biomarkers, 60 consecutive patients undergoing OPCAB were monitored for myocardial injury (myoglobin), inflammation (TNF-alpha, IL-8) and thrombosis (thrombin generation-F1.2, contact activation pathway-FXII-a, platelet derived microparticles-via flow cytometry). The transcardiac gradients of these markers were determined by assaying both arterial and coronary sinus blood just after protamine administration. Intramyocardial pH was monitored continuously during coronary occlusion in a subset (N=30 grafts, 11 patients). The influence of management strategies affecting hemostasis (e.g. antiplatelet therapy, anti-fibrinolytics, peak activated clotting time (ACT) during heparinization) was analyzed. RESULTS: Ischemic injury, depicted by the transcardiac myoglobin gradient, significantly correlated with intramyocardial acidosis during coronary occlusion (R=0.96, p<0.0001) and predicted the transcardiac gradients of TNF-alpha (R=0.83, p<0.001) and F1.2 (R=0.72, p<0.0001). Transcardiac F1.2 strongly correlated with TNF-alpha (R=0.73, p=0.01) and IL-8 (R=0.51, p=0.02). Patients receiving aprotinin (N=20) showed significantly lower transcardiac gradients for myoglobin (4.1+/-7.5% vs 72.9+/-108.8% change, p=0.002), F1.2 (31+/-37% vs 89+/-149%, p=0.03), FXII-a (2.6+/-4.1% vs 19.2+/-34%, p=0.04) and microparticles (7+/-3.9% vs 12.9+/-8%, p=0.01). CONCLUSIONS: Strong correlations between myocardial ischemia and the transcardiac gradients of markers for inflammation and thrombosis suggest that even brief episodes of coronary occlusion in the beating heart may have pathophysiologic consequences. Aprotinin, but not other factors that influence the coagulation system, appears to mitigate this process during OPCAB.

Effects of CoQ10 supplementation on plasma lipoprotein lipid, CoQ10 and liver and muscle enzyme levels in hypercholesterolemic patients treated with atorvastatin: a randomized double-blind study.

The long-term efficacy and safety of HMG-CoA reductase inhibitors (statins) have been established in large multicenter trials. Inhibition of this enzyme, however, results in decreased synthesis of cholesterol and other products downstream of mevalonate, such as CoQ10 or dolichol. This was a randomized double-blind, placebo-controlled study that examined the effects of CoQ10 and placebo in hypercholesterolemic patients treated by atorvastatin. Eligible patients were given 10mg/day of atorvastatin for 16 weeks. Half of the patients (n=24) were supplemented with 100mg/day of CoQ10, while the other half (n=25) were given the placebo. Serum LDL-C levels in the CoQ10 group decreased by 43%, while in the placebo group by 49%. The HDL-C increment was more striking in the CoQ10 group than in the placebo group. All patients showed definite reductions of plasma CoQ10 levels in the placebo group, by 42%. All patients supplemented with CoQ10 showed striking increases in plasma CoQ10 by 127%. In conclusion atorvastatin definitely decreased plasma CoQ10 levels and supplementation with CoQ10 increased their levels. These changes in plasma CoQ10 levels showed no relation to the changes in serum AST, ALT and CK levels. Further studies are needed, however, for the evaluation of CoQ10 supplementation in statin therapy.

Redox instability induced by 4-hydroxy-2-nonenal in porcine and bovine myoglobins at pH 5.6 and 4 degrees C.

Myoglobin (Mb) redox stability affects meat color and is compromised by lipid oxidation products such as 4-hydroxy-2-nonenal (HNE). Pork lipids are generally more unsaturated and would be expected to oxidize readily and produce more oxidation products than beef. Supranutritional supplementation of vitamin E improves Mb redox stability of beef but not pork. The present study investigated HNE-induced redox instability in porcine and bovine myoglobins at 4 degrees C and pH 5.6. Oxymyoglobin (OxyMb) was incubated with HNE (0.075 mM porcine OxyMb + 0.5 mM HNE; 0.15 mM bovine OxyMb + 1.0 mM HNE). In porcine Mb, only monoadducts formed via Michael addition were detected after 72 h, whereas in bovine Mb both mono- and diadducts were identified. LC-MS-MS identified four histidine residues (His 36, 81, 88, and 152) of bovine Mb that were readily adducted by HNE, whereas in porcine Mb only two histidine residues (His 24 and 36) were adducted. These results suggested that the primary structure of bovine Mb predisposes it to greater nucleophilic attack by HNE and subsequent adduction than is suffered by porcine Mb.

Anti-TNF antibody treatment improves glucocorticoid induced insulin-like growth factor 1 (IGF1) resistance without influencing myoglobin and IGF1 binding proteins 1 and 3.

BACKGROUND: Insulin-like growth factor 1 (IGF1) is an important determinant of muscle mass because it promotes growth and suppresses protein degradation. IGF1 is decreased in rheumatoid arthritis and juvenile idiopathic arthritis because its synthesis is inhibited by inflammation. In parallel, glucocorticoids induce IGF1 resistance and add to muscle degradation. OBJECTIVE: To investigate the influence of anti-tumour necrosis factor antibody treatment (anti-TNF) with adalimumab on levels of myoglobin (degradation marker) and IGF1 in patients with rheumatoid arthritis with and without prednisolone treatment. METHODS: Subcutaneous adalimumab was given to 32 patients with longstanding rheumatoid arthritis (16 with and 16 without prednisolone) in a longitudinal study. IGF1, IGF1 binding protein 1 (IGFBP-1), IGFBP-3, and myoglobin were measured by enzyme linked immunosorbent assay. RESULTS: Rheumatoid patients had normal serum myoglobin. Patients on prednisolone had higher myoglobin than patients not receiving prednisolone, indicating increased muscle degradation. On treatment with anti-TNF, myoglobin levels did not change in either patient group. Serum IGF1 was increased in patients with v without prednisolone, indicating IGF1 resistance (mean (SEM): 221 (23) v 122 (14) microg/l, p<0.001). Adalimumab treatment decreased the raised IGF1 levels in patients with prednisolone, so that after 12 weeks of treatment they reached the level of patients without prednisolone. Serum IGFBP-1 and IGFBP-3 did not differ in the two groups, and anti-TNF did not change these concentrations. CONCLUSIONS: Anti-TNF antibody treatment over 12 weeks improved glucocorticoid induced IGF1 resistance without influencing myoglobin and IGF1 binding proteins. Thus, in rheumatoid patients on glucocorticoids with generally decreased muscle mass anti-TNF treatment with adalimumab has favourable effects.