Search results for "Biochemistry"
showing 10 items of 20172 documents
Is Myeloperoxidase a Key Component in the ROS-Induced Vascular Damage Related to Nephropathy in Type 2 Diabetes?
2013
AbstractIt is still unclear whether microvascular complications of type 2 diabetes correlate with leukocyte-endothelium interactions and/or myeloperoxidase (MPO) levels. In the present study, we found that serum levels of glucose, the rate of ROS and MPO concentration were higher in type 2 diabetic patients. Patients with nephropathy (39.6%) presented higher MPO levels that correlate positively with the albumin/creatinine ratio (r=0.59, p<0.05). In addition, nephropatic patients showed increased leukocyte-endothelium interactions due to an undermining of polymorphonuclear leukocytes (PMN) rolling velocity and increased rolling flux and adhesion, which was accompanied by a rise in levels of …
Substance P inactivation by transglutaminase in vitro.
1992
Gamma(glutamyl5)spermine derivative of substance P (Spm-SP) was synthesized in vitro in the presence of purified guinea pig liver transglutaminase and Ca2+. The spermine adduct of the neuropeptide was purified by HPLC on a reversed-phase column and characterized by fast atom bombardment mass spectrometry. The biological activities of Spm-SP were tested by assaying, in comparison with substance P, its ability to induce both the contractions of smooth muscle in vitro and the edema formation in vivo. Spm-SP was shown not to elicit contractile responses in the isolated rat stomach strip and duodenum and not to antagonize the spasmogenic effect evoked by the native neuropeptide. Furthermore, Spm…
Role of the gamma-glutamyl cycle in the regulation of amino acid translocation
1989
Amino acid translocation was studied in the mammary gland of lactating rats and in the placenta of pregnant rats. The uptake of amino acids by the mammary gland is maximal on days 10-14 of lactation and is minimal on days 19-21. However, on day 19 maximal uptake can be restored by injection of 1) small amounts of gamma-glutamyl amino acids, 2) 5-oxoproline, and 3) an inhibitor of 5-oxoprolinase. A severe decrease in uptake of amino acids at the peak of lactation is provoked by anthglutin, an inhibitor of gamma-glutamyltranspeptidase (GGT). Simultaneous injection of 5-oxoproline blocks these effects of anthglutin. In pregnant rats, inhibition (79%) of placental GGT activity by acivicin resul…
Lipid peroxidation capacities in the myocardium of endurance-trained rats and mice in vitro.
1992
The endurance-training programme in Experiment 1 (Exp. 1) consisted of a total swimming time of 149–159 h per male Han Wistar rat and in Experiment 2 (Exp. 2) the male NMRI-mice run on a treadmill at a speed of 25 m min-1 1 h per day, 5 days a week for 3 weeks. One group of the rat hearts was perfused with 0.3 mm cumene hydroperoxide (CumOOH) while the others were fractioned (mitochondria, sarcolemma and sarcoplasmic reticulum) and these cell fractions and homogenates were used to determine the total concentration of peroxidative lipids and the susceptibility to lipid peroxidation. The perfusion with CumOOH caused the release of thiobarbituric acid reactive substances (TBARS) into the perfu…
Inter-relationship between platelet-derived microparticles and oxidative stress in patients with venous thromboembolism
2020
Background: Hypercoagulative conditions play a key role in venous thromboembolism (VTE). Inflammation is currently linked to VTE, but the potential role of circulating microparticles and oxidative stress (OxS) must be elucidated. The aim of this study was to evaluate platelet-derived microparticles and surrogate OxS biomarkers in patients diagnosed with VTE through a case&ndash
Trainability of underwater breath-holding-time
1982
From diving practice we know that breath-holding time (BHT) can be increased by training. This examination was set up to illuminate whether BHT underwater can be trained decisively in a short period of time. The authors investigated whether physiologic or psychological aspects are the main constituents of the above-mentioned BHT phenomenon. BHT and the "onset point" of involuntary respiratory movements of 64 subjects were registered after deep inspiration and immersion in ca. 1 m. Two different tests were set up: (I) 2 breath-holds per day on 5 consecutive days, (II) 5 repeated breath-holds with pauses of 3 min in between. BHT of the first test was shorter underwater than in similar experim…
P674Metabolic deregulation in myocardial infarction is mediated by PGC-1 alpha pathway
2014
Purpose: In the context of myocardial infarction (MI) the availability of metabolites is clearly restricted, therefore a fuel metabolic shifts takes place. Previous studies have indicated that peroxisome proliferator activated receptor co-activator alpha (PGC-1α) pathway is a crucial regulator of cardiac metabolism in response to cardiac stress. Here we address the role of PGC-1α in regulating metabolic changes of MI. Methods: We studied a group of 12 common swine in which anterior MI was induced by means of angioplasty balloon inflation. A series of 6 swine were sacrificed at 48h post-infarction (acute infarction group) and another series of 6 swine were sacrificed at 3 weeks (chronic infa…
PAP/HIP Protein Is an Obesogenic Factor
2013
In this article we report the obesogenic role of the acute phase protein PAP/HIP. We found that the transgenic TgPAP/HIP mice develop spontaneous obesity under standard nutritional conditions, with high levels of glucose, leptin, and LDL and low levels of triglycerides and HDL in blood. Accordingly, PAP/HIP-deficient mice are skinny under standard nutritional conditions. We also found that expression of PAP/HIP is induced in intestinal epithelial cells in response to gavage with olive oil and this induction is AG490 sensitive. We demonstrated that incubation of 3T3-L1 preadipocytes with a low concentration as 1 ng/ml of recombinant PAP/HIP results in accelerated BrdU incorporation in vitro.…
Turpentine-induced fever during stimulation and inhibition of hepatic protein synthesis
2003
Abstract 1. Male Wistar rats pretreated with d -galactosamine (500 mg/kg, i.p.), a specific inhibitor of hepatic protein synthesis, developed attenuated and prolonged fever in response to turpentine (0.5 ml/rat, s.c.). 2. Hepatic protein synthesis stimulator epinephrine (1.8 mg/kg, s.c.) did not affect body temperature response of Wistar rats to turpentine. 3. Both d -galactosamine (500 mg/kg) and epinephrine (1.8 mg/kg) failed to affect body temperature in non-febrile rats. 4. These data support the hypothesis that liver-synthesised acute phase proteins might be involved in mechanisms of fever, probably, as modulators of activated cytokine network, mediating febrile response.
A systematic review of physical fitness, physiological demands and biomechanical performance in equestrian athletes
2012
This article presents a systematic review of the literature investigating physical fitness, physiological demands and biomechanical performance in equestrian athletes. Three databases (SportsDiscus, CAB abstracts and PubMed) were searched to identify the literature. The main search term of ‘horse-riding’ was combined with eleven specific keywords (‘fitness’, ‘physiology’, ‘biomechanics’, ‘equestrian’, ‘athlete’, ‘co-ordination’, ‘heart rate’, ‘oxygen consumption’ ‘kinematic’ ‘EMG’ and ‘skill’). Exclusion criteria were: conference proceedings, abstracts, theses, and non-peer reviewed articles. Subsequently, 15 peer-reviewed papers were identified and included within this review. The main re…