Impact of dextran on microvascular disturbances and tissue injury following ischemia/reperfusion in striated muscle.
Shock
; 9(5): 345-51, 1998 May.
Article
en En
| MEDLINE
| ID: mdl-9617884
ABSTRACT
The aim of this study was to evaluate the effect of dextran (Dx) 1 versus Dx 60 (molecular weights 1,000 and 60,000) on microvascular disturbances and tissue injury in striated muscle after ischemia/reperfusion (I/R). Experiments were performed using a 4 h pressure-induced ischemia model in the hamster dorsal skinfold chamber. Three groups (n=6) of animals received a continuous infusion (45 min, 3 microL/min) of either Dx 1 or Dx 60 (total dose 5 mg/kg) or saline solution beginning 15 min before reperfusion. Intravital fluorescence microscopy allowed for quantification of functional capillary density, leukocyte adherence, extravasation of fluorescein isothiocyanate-Dx, and nonviable (propidium-positive) cell count before ischemia and .5, 2, and 24 h after reperfusion. Experiments were terminated with tissue preservation for electron microscopy. Postischemic functional capillary density was significantly improved by Dx 60 (at 24 h, 88% vs. 51% in controls). In animals receiving postischemic Dx 1 or Dx 60, leukocyte adherence was significantly reduced (at .5 h, 44% and 58%, respectively) as compared with controls, whereas macromolecular extravasation was unchanged. Nonviable cell count was significantly decreased by both Dx fractions (at 24 h, Dx 1, 75%; Dx 60, 87%), indicating a reduction of tissue injury, which was also confirmed by electron microscopy. These results provide evidence that Dx 60 at 5 mg/kg attenuates I/R injury more effectively than Dx 1. Leukocytes play a major role in the development of I/R injury, but macromolecular extravasation does not always correlate with the leukocyte-endothelium interaction and the manifestation of I/R injury.
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Bases de datos:
MEDLINE
Asunto principal:
Reperfusión
/
Dextranos
/
Músculo Esquelético
/
Isquemia
/
Microcirculación
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
Shock
Asunto de la revista:
ANGIOLOGIA
/
CARDIOLOGIA
Año:
1998
Tipo del documento:
Article
País de afiliación:
Alemania