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Microvascular function at the margins of early experimental myocardial infarcts in isolated rabbit hearts (1986)

Sage, Martin D. ; Gavin, John B.

Springer

Heart and vessels 2 (1986), S. 81-86

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ISSN: 1615-2573

Keywords: Ischemia ; Infarct progression ; Reperfusion ; Scanning electron microscopy ; Coronary occlusion

Source: Springer Online Journal Archives 1860-2000

Topics: Medicine

Notes: Summary Injection of low-viscosity resin was used to identify in situ functional blood vessels at the margins of developing regional myocardial infarcts. The ventral interventricular branch (VIB) of the left coronary artery was occluded for 0–240 min in 20 isolated perfused rabbit hearts. After perfusion fixation with glutaraldehyde, resin was injected into the coronary arteries—that injected into the VIB contained dispersed lead dioxide and that injected into the remainder of the heart contained Fat Red 7B dye. This allowed macroscopic and microscopic identification of functional blood vessels. Following transmural freeze fracture, left ventricles were examined using back-scattered electron imaging in a scanning electron microscope. Close to 60% of capillaries in nonischemic myocardium allowed the passage of resin. Thirty minutes of ischemia produced a hyperemic increase to 80%–90% in the proportion of filled vessels. After 60 min, however, a severe reperfusion defect corresponding to the “no-reflow” phenomenon had developed, with virtually all vessels collapsed and 〈10% functional. Among the structurally normal myocytes adjacent to the infarct margin there was a significant reduction (to 30%–40%) in the proportion of functional capillaries. This was due to groups of dilated vessels which were not accessible to arterial supply. Although these marginal “low-flow” regions were of small volume at any one point in time, they seem likely to contribute to the progression of ischemic necrosis, and are probably nonfunctional due to the compression of their venous drainage traversing the infarct.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF02059960

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Catalase activity in human spermatozoa and seminal plasma (1989)

Jeulin, C. ; Soufir, J. C. ; Weber, P. ; [et al.]

New York, NY : Wiley-Blackwell

Gamete Research 24 (1989), S. 185-196

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ISSN: 0148-7280

Keywords: free radicals ; Life and Medical Sciences ; Cell & Developmental Biology

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Biology

Notes: Catalase activity was determined in human semen by measuring the oxygen burst with a Clark electrode, after H2O2 addition. Significant catalase activities (mean ± SD) were found in migrated, motile spermatozoa (44 ± 17 nmoles O2/min/108 cells) and in seminal plasma of normozoospermic men (129 ± 59 nmoles O2/min/ml). It has been demonstrated that seminal catalase originated from prostate; however, its activity was not correlated with the usual prostatic markers (such as citric acid and zinc). Our data suggest a multiglandular function secreted by this organ. The catalase activities measured in seminal samples from asthenozo-ospermic, infertile men were found lower than those from normozoospermic subjects. The understanding of the relative contribution of the different enzyme systems against O2 toxicity (superoxide dismutase, catalase, glutathione peroxidase) seem to be a priority area of research to understand disturbances of sperm function.

Additional Material: 3 Ill.