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  • 1
    ISSN: 1432-0738
    Keywords: Key words Chlorodibromomethane ; Trichloromethane ; Cardiotoxicity ; [Ca2+] i transients ; Catecholamine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The cardiovascular effects were investigated after acute and subacute treatment with chlorodibromomethane (CDBM; 0.4 to 3.2 mmol/kg p.o.), trichloromethane (TCM; 0.31 and 1.25 mmol/kg p.o.) and mixtures of CDBM and TCM (acute, 0.8 mmol CDBM/kg + 1.25 mmol TCM/kg p.o.; subacute, 0.4 mmol CDBM/kg+0.31 mmol TCM/kg p.o.) in conscious and urethane anaesthetized male Wistar rats (n=610 per treatment). Furthermore it was observed whether cardiovascular responses were modified in CDBM or TCM treated rats after administration of exogenous catecholamines (epinephrine, 1 μg/kg; norepinephrine, 2 μg/kg) and underpinned with in vitro alterations of Ca2+ dynamics in cardiac myocytes. The present findings demonstrated that single and subacute oral administration of CDBM or TCM and mixtures of CDBM and TCM resulted in arrhythmogenic and negative chronotropic and dromotropic effects in conscious and urethane anaesthetized rats. The atrioventricular conduction time and the intraventricular extension time were extended. A slight shortening of the repolarization velocity was observed. The myocardial contractility was depressed and the heart was sensitized to the arrhythmogenic effects of epinephrine. After catecholamine injection the adrenergic cardiovascular responses in urethane anesthetized rats were modified: increased hypertensive epinephrine and norepinephrine action as well as augmentation of negative chronotropic and negative dromotropic cardiac effects of catecholamines were observed. The positive inotropic adrenergic response was diminished. The present in vivo findings, myocardial depression after acute CDBM treatment, as determined by different indices of contractility, correlate well with the observed inhibitory actions of CDBM on Ca2+ dynamics in isolated cardiac myocytes. All cardiovascular alterations found after CDBM or TCM treatment were not intensified after treatment with mixtures of CDBM and TCM. The effects observed were distinctly stronger after TCM (1.25 and 0.31 mmol/kg) treatment compared to CDBM (0.8 and 0.4 mmol/kg) treatment.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-1246
    Keywords: Physical Strain and Stress ; Long-distance March ; Catecholamines ; Glucocorticoids ; Cyclic Nucleotides ; Physische Belastung und Beanspruchung ; Langstreckenmarsch ; Catecholamine ; Glucocorticoide ; cylische Nukleotide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Beanspruchung in Arbeit und Beruf und ihre Auswirkungen auf biochemische Größen stehen seit Jahren zur Diskussion. In vorliegender Studie sollte das Verhalten verschiedener biochemischer Parameter bei physischer Belastung geprüft werden. Wir untersuchten Blut- und Urinproben von 31 Offiziers-anwärten der Bundeswehr vor und unmittelbar im Anschluß an einen Langstrecken marsch von 25 km. Analysiert wurden das Laktat im Vollblut, Noradrenalin, Cortisol und die cyclischen Nukleotide c-AMP und c-GMP im Plasma sowie Adrenalin, Noradrenalin, Vanillinmandelsäure und die 17-Hydroxycorticosteroide im Urin. Signifikante Erhöhungen ergaben sich für die Konzentrationen der Catecholamine und der cyclischen Nukleotide nach der physischen Belastung. Keine signifikanten Abweichungen waren für die Substanzen des Glucocorticoid-Stoffwechsels festzustellen. Die einzelnen Parameter werden hinsichtlich ihrer Relevanz für die Objektivierung physischer Beanspruchung diskutiert.
    Notes: Summary The study presented was performed to evaluate the behaviour of some stress-related biochemical parameters induced by physical stress. We investigated urine and blood samples of 32 graduating officers of the German Bundeswehr before and after a long-distance march over 25 km. The concentrations of lactate in blood, noradrenaline, cortisol and the cyclic nucleotides c-AMP and c-GMP in plasma and adrenaline, noradrenaline, vanillic mandelic acid and 17-hydroxycorticosteroids in urine were determined. Significant elevations were detectable for the concentrations of catecholamines and cyclic nucleotides after the physical work-load. No significant differences were observed for the substances of the glucocorticoid metabolism. The single parameters are discussed in respect to their significance for the objectification of physical strain.
    Type of Medium: Electronic Resource
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