The human endotoxin model has been used to study the early phase of sepsis. The aim of the present study was to assess leg muscle protein kinetics after an endotoxin challenge given to healthy human volunteers. Six healthy male subjects were studied in the post-absorptive state before and during 4 h following an intravenous endotoxin bolus (4 ng/kg of body weight). Primed continuous infusion of [(2)H(5)]phenylalanine and [(2)H(3)]3-methylhistidine in combination with sampling from the radial artery, femoral vein and muscle tissue were used to assess leg muscle protein kinetics. Both two- and three-compartment models were used to calculate protein kinetics. In addition 26S proteasome activity and protein ubiquitination were assessed. An increase in the net release of phenylalanine from the leg following the endotoxin challenge was observed; however, this phenylalanine originates from the free intracellular pool and not from protein. Net protein balance was unchanged, whereas both protein synthesis and breakdown were decreased. Degradation rates of contractile proteins were not affected by endotoxin, as indicated by an unchanged rate of appearance of 3-methylhistidine from leg muscle. In addition, proteasome activity and protein ubiquitination were unaffected by endotoxaemia. In conclusion, intravenous endotoxin administration to healthy volunteers resulted in an increased release of free phenylalanine from skeletal muscle, whereas protein balance was unaffected. Both protein synthesis and breakdown were decreased to a similar extent.

Dynamic changes in the interstitial concentrations of the glucose, glycerol, pyruvate and lactate were found in both groups of patients (off-pump and on-pump). The presented preliminary results suggest that extracorporeal circulation during cardiac operations could compromise skeletal muscle energy metabolism.

This work describes the method for total antioxidant capacity (TAC) and/or total content of phenolics (TCP) analysis in wines using microdialysis online-coupled with amperometric detection using a carbon microfiber working electrode. The system was tested on 10 selected wine samples, and the results were compared with total reactive antioxidant potential (TRAP), oxygen radical absorbance capacity (ORAC), and chemiluminescent determination of total antioxidant capacity (CL-TAC) methods using Trolox and catechin as standards. Microdialysis online-coupled with amperometric detection gives similar results to the widely used cyclic voltammetry methodology and closely correlates with ORAC and TRAP. The problem of electrode fouling is overcome by the introduction of an electrochemical cleaning step (1−2 min at the potential of 0 V vs Ag/ AgCl). Such a procedure is sufficient to fully regenerate the electrode response for both red and white wine samples as well as catechin/Trolox standards. The appropriate size of microdialysis probes enables easy automation of the electrochemical TAC/ TCP measurement using 96-well microtitration plates.

ABSTRACT:The alkaloids of Macleaya cordata (Papaveracae) are active components of the phytogenic feed additive Sangrovit. The present study was conducted to evaluate the effects of Sangrovit on dextran sulfate sodium (DSS)-induced colitis using rats as an experimental model. Thirty-five male rats were randomly assigned to a control group (Group 1, n = 5), a Sangrovit group (Group 2, n = 20) and a DSS group (Group 3, n = 10). Group 1 received standard diet and tap water for 14 days. Group 2 received 500 ppm Sangrovit in their feed for 14 days and in the second week 5% DSS was added to the tap water. The animals in Group 3 were fed for seven days with standard diet and tap water and for the next seven days with standard diet and 5% DSS added to their tap water. The rats were sacrificed on day 14 and the following parameters were measured: disease activity (body and organ weight, colon length, presence of blood in stool), colon myeloperoxidase activity, expression of colon cyclooxygenase-2 (COx-2), hematological parameters, histological colitis score and selected parameters of oxidative stress. The animals treated with DSS for seven days (Groups 2 and 3) showed increases in liver and cecum weight, leukocyte count and colon shortening, decreases in hemoglobin and hematocrit associated with hematochezia. In comparison with Group 3 where DSS caused mucosal edema, cellular infiltration and epithelial disruption, the Sangrovit group showed less severe damage to the colon mucosa and decreased histological colitis scores. The Sangrovit group also showed diminished expression of DSS-induced COx-2, significantly mitigated myeloperoxidase activity in colon tissue and level of reduced glutathione in erythrocytes. In conclusion, some parameters of DSS-induced colitis were modulated by 500 ppm Sangrovit added to feed. Keywords: Macleaya cordata; Papaveraceae; benzo[c]phenanthridines; protopines; feed additive; dextran sulfate sodium-induced colitis; cyclooxygenase-2; myeloperoxidase List of abbreviations AL = allocryptopine, CH = chelerythrine, COX-2 = cyclooxygenase-2, DHCH = dihydrochelerythrine, DHSG = dihydrosanguinarine, DSS = dextran sulfate sodium, GSH = reduced glutathione, GST = glutathione transferase, IBD = inflammatory bowel disease, MPO = myeloperoxidase, PR = protopine, QBA = quaternary benzo[c]phenanthridine alkaloids, SG = sanguinarine, TBARS = thiobarbituric acid reactive substances, TMB = tetramethylbenzidine

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