Search results for "Myocardium"
showing 10 items of 365 documents
Lysosomal changes related to ageing and physical exercise in mouse cardiac and skeletal muscles.
1982
Physical exercise increased the activities of arylsulphatase, cathepsin D and β-glucuronidase in mouse skeletal muscle but not in cardiac muscle. Exercise-induced lysosomal response was more prominent in young adult than in senescent mice. The lipofuscin content of cardiac and skeletal muscles increased markedly during ageing and was also found to increase slightly after exertion in young mice, but not in senescent ones.
Iridoid extracts from Ajuga iva increase the antioxidant enzyme activities in red blood cells of rats fed a cholesterol-rich diet.
2010
The lyophilized aqueous extract of Ajuga iva (Ai) is able to reduce oxidative stress, which may prevent lipid peroxidation in hypercholesterolemic rats. Iridoids (I) were isolated from Ai. We hypothesized that the antioxidant defense status in red blood cells (RBC) and tissues in rats fed a cholesterol-rich diet and treated with Ai may be correlated to these compounds. Male Wistar rats (n = 32) weighing 120 +/- 5 g were fed a diet containing 1% cholesterol for 15 days. After this phase, hypercholesterolemic (HC) rats were divided into groups, fed the same diet, and received either the same or different doses (5, 10, or 15 mg/kg body weight by intraperitoneal injection) of I for 15 days. Com…
Decreased level of cardiac antioxidants in endurance-trained rats.
1989
Han-Wistar rats were exposed to a 194-200 h swimming protocol which caused a significant increase in the cardiac weight. The levels of various tissue antioxidants were assayed from the myocardium of the right ventricle and from the left ventricle (subendo- and subepimyocardium). This endurance training decreased the activities of catalase in the right ventricle and in the subendo- and subepimyocardium and Cu,Zn-superoxide dismutase in the subendomyocardium as well as the concentration of vitamin E in the right ventricle and in the subendomyocardium. Also, the activity of thioredoxin reductase decreased in each part of myocardium and that of glutathione reductase in the right ventricle and i…
Acid proteolytic capacity in mouse cardiac and skeletal muscles after prolonged submaximal exercise
1980
Acid proteolytic capacity in mouse cardiac muscle and in predominantly white (distal head of m. vastus lateralis) or predominantly red (proximal red heads of m. vastus lateralis, m. v. medialis, and m. v. intermedius) skeletal muscle was estimated 5 days after 3 h, 6 h or 9 h prolonged running at a speed of 13.5 m/min. The activities of acid protease and beta-glucuronidase together with the rate of acid autolysis considerably increased in both skeletal muscle types, especially in red muscle, but did not increase in cardiac muscle. Acid proteolytic capacity and beta-glucuronidase activity increased in relation to the duration of running. Protein content and oxidative capacity (the activities…
Different muscarinic receptors mediate autoinhibition of acetylcholine release and vagally-induced vasoconstriction in the rat isolated perfused heart
1990
Experiments were carried out on rat isolated perfused hearts with both vagus nerves attached. The acetylcholine stores were labelled with [14C]-choline. The effects of muscarinic receptor antagonists on the [14C]-overflow and increase in perfusion pressure evoked by vagus nerve stimulation (10 Hz, 4-10 mA) were studied in order to determine the muscarinic receptor type involved in autoinhibition of acetylcholine release and vagally-induced vasoconstriction in the rat heart. Stimulation of the vagus nerves (1200 pulses) caused an increase in [14C]-overflow and in perfusion pressure which was significantly reduced by hexamethonium 500 mumol/l and abolished by tetrodotoxin 0.3 mumol/l or perfu…
Arrhythmias and inhibition of noradrenaline uptake caused by tricyclic antidepressants and chlorpromazine on the isolated perfused rabbit heart
1975
1. Isolated rabbit hearts were perfused with a modified Tyrode solution containing noradrenaline in concentrations increasing stepwise from 5.9 nM to 5.9 μM at 5 min intervals. This dose regime was applied twice before and once 20 min after starting perfusion with one of 9 tricyclic drugs. Ventricular rate and right atrial and ventricular tensions were recorded using the transverse method. 2. Infusions of noradrenaline evoked ventricular arrhythmias in hearts perfused with amitriptyline 4.8 μM, chlorpromazine 5.0 μM, desipramine 5.0 μM, dibenzepine 34.7 μM, doxepin 4.7 μM, imipramine 4.7 μM, noxiptiline 9.1 μM and opipramole 9.2 μM. The incidence of arrhythmias increased with the concentrat…
Effect of low levels of dietary fish oil on fatty acid desaturation and tissue fatty acids in obese and lean rats
1995
The effect of very low levels of dietary long-chain n-3 fatty acids on delta 6 desaturation of linoleic acid (18:2n-6) and alpha-linolenic acid (18:3n-3), and on delta 5 desaturation of dihomo-gamma-linolenic acid (20:3n-6), in liver microsomes and its influence on tissue fatty acids were examined in obese and lean Zucker rats and in Wistar rats. Animals fed for 12 wk a balanced diet containing ca. 200 mg of long-chain polyunsaturated n-3 fatty acids per 100 g of diet were compared to those fed the same amount of alpha-linolenic acid. Low amounts of long-chain n-3 fatty acids greatly inhibited delta 6 desaturation of 18:2n-6 and delta 5 desaturation of 20:3n-6, while delta 6 desaturation of…
Contribution of both ?- and ?-adrenoceptors to the inotropic effects of catecholamines in the rabbit heart
1992
The functional role of alpha-adrenoceptors was investigated in different parts of the rabbit heart. Phenylephrine (PE) caused a marked increase in force of contraction (Fc) and a prolongation of the action potential (AP) in preparations from the left atrium and the right ventricle. The response was less pronounced in the right atrium and in the left ventricle, whereas APs of spontaneously beating sinoatrial preparations remained completely unchanged. Phentolamine as well as the diesters phorbol 12,13 dibutyrate (PDBu) or 12-O-tetradecanoyl-phorbol-13-acetate (TPA) eliminated the effects of PE. The contribution of alpha-adrenoceptors to the effects of adrenaline (Adr) and noradrenaline (NA) …
Troponin I concentrations of shed blood might influence monitoring of myocardial injury after coronary operations.
2002
Abstract In a prospective study we evaluated the concentration of cardiac troponin I (cTnI) and creatine kinase activities (CK) in shed mediastinal blood in the early postoperative period after coronary artery bypass grafting (CABG). Forty seven patients who underwent first time elective CABG were studied. CTnI levels and CK activities in arterial blood and shed mediastinal blood were measured after admission to the intensive care unit (ICU) and 6 h after unclamping the aorta. Mediastinal shed blood samples were drawn from 23 patients (group A) before the filter of the cardiotomy reservoir and from 24 patients (group B) behind. Additionally, both markers were measured in blood samples colle…
Protection effect of endurance training against reoxygenation-induced injuries in rat heart
1990
Endurance training by swimming (219-229 h) resulted in a significant protection against hypoxia/reoxygenation-induced injuries in Langendorff-perfused rat hearts. The protection was manifested as improved flow characteristics and a smaller release of creatine kinase into the perfusate. The concentration of thiobarbituric acid reactive substances (TBARS) was lower in the trained than in the respective control hearts. The trained hearts also showed a lower reoxygenation-induced increase in TBARS. The myocardium of the right ventricle and that of the left subepimyocardium were the most affected by reoxygenation. The swimming program induced a decrease in the activities of catalase and glutath…