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  • 31P-NMR spectroscopy  (1)
  • Aging  (1)
  • 1
    ISSN: 1573-4919
    Keywords: cardioprotection ; regional myocardial function ; 31P-NMR spectroscopy ; EPR spectroscopy ; thiophosphate ; WR-2721
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract S-2-(3 aminopropylamino) ethylphosphorothioic acid (WR-2721) shown to surpass radical scavenging thiols in their radioprotective efficacy in cancer-type diseases has been tested for its protective potential in the reperfused heart. We investigated the radical scavenger properties of the compound in a radical generating systemin vitro as well as in isolated rat hearts subjected to 30 min ischaemia and 30 min reperfusion with the electron-paramagnetic resonance spin trap technique. The action on high-energy phosphates is observed by means of phosphorus-31 nuclear magnetic resonance (NMR) spectroscopy while its influence on left ventricular systolic segmental length change (SSLC) during 60 min reperfusion following 60 min regional ischaemia was assessed with a fibreoptic system in anaesthetized open-chest rats. WR-2721 (0.1 mM) reduced the vascular concentration of radical adduct in isolated hearts by up to 78% (275±84% of pre-ischaemic baseline values vs 1260±413%, p〈0.05) between 5 and 12.5 min reperfusion. This was accompanied by a reduction of the left ventricular end diastolic pressure to pre-ischaemic values at 30 min of reperfusion (9±6 mmHg vs 42±8 mmHg in the absence of WR-2721, p〈0.02). An accelerated recovery of creatine phosphate levels (78±5% of pre-ischaemia values vs 41±5% within 60 min reperfusion; p〈0.05) was observed under similar conditions with NMR-spectroscopy, although the post-ischaemic tissue content of adenosine triphosphate was not affected. The administration of WR-2721 (0.5 mmol/kg body weight) ledin situ to an accelerated restoration of contractile activity in the post-ligated left ventricular area reflected by the post-ischaemic recovery of SSLC (64±10% of pre-ischaemic values compared with 27±6% in control animals 60 min following reperfusion; p〈0.02). The present data confirm an effective reduction in the exposure of the reperfused heart to endogenously released free radicals by WR-2721, a partial preservation of high-energy phosphates and an improvement in post-ischaemic contractility and encourage further investigation of such favourable action in injured myocardium.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Hoboken, NJ [u.a.] : Wiley-Blackwell
    Journal of Orthopaedic Research 5 (1987), S. 467-478 
    ISSN: 0736-0266
    Keywords: Viscoelasticity ; Creep analysis ; Lumbar motion segment ; Compression ; Disc degeneration ; Aging ; Life and Medical Sciences
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The in vitro viscoelastic “creep” behavior was examined in 18 cadaveric human lumbar motion segments subjected to static axial compressive loads. Axial deformation was followed for 30 min under constant applied load. Compressive material constants (moduli and viscosity coefficients) were then determined for each intervertebral disc using a linerization method based on a Taylor series expansion of experimental data for the “three parameter” viscoelastic creep model. The degree of disc degeneration and bone mineral content (BMC) were also assessed. Good correlation between the experimentally determined and model predicted strain values were found, with the average error 〈1%. We found that motion segments from older and more degenerated lumbar discs were less stable and had lower material constants than segments from younger and less degenerated discs. Material constants and BMC correlated closely, suggesting that an interdependency of disc and vertebral body properties exists. No correlation between the creep characteristics and disc height, disc area, segment level, or sex were noted.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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