RESUMEN
Objective: To test the feasibility of drag-reducing polymers (DRP) for improving coronary microcirculation in a canine model in order to provide the experimental basis for treating myocardial microcirculation dysfunction. Methods: A total of 8 dogs received open-chest surgery and they had intravenous injections, in turn, with adenosine (ADN), DRP 250 mg/L and DRP+ADN. The function y=A × (1-e-βt) was used to calculate the myocardium capillary volume (A value), capillary velocity (β value) and myocardial blood lfow (A ? β value) by myocardial contrast echocardiography. Results: With DRP infusion, the A value in experimental canine was similar to the baseline condition,P>0.05; while theβ value and A ? β value were signiifcantly increased as (0.57 ± 0.10) 1/s vs (0.23 ± 0.03) 1/s,P0.05. Conclusion: DRP improved coronary microcirculation primarily by modulating the β value in experimental canine model, and hopefully, this unique hemodynamics could provide a new approach for treating myocardial microcirculation dysfunction.
RESUMEN
Objective To investigate the effects of drag-reducing polymers on microcirculation in 40%total body surface area burn-injured rats. Methods SD rats were randomized into control group, drag-reducing polymer (DRPs) group and normal saline (NS) group (5 minutes after scald, drag-reducing polymer or saline was injected for fluid resuscitation). Wet dry weigh ratio of lung, histopathologic changes and arterial blood gas at 24 hour were respectively measured by wet dry weigh ratio method, hematoxylin-eosin (HE) staining and arterial blood gas analysis. The velocity of flow of red cell in oblique ridge and the survival time of burn-injured rats were observed. Results Compared with control group, rats in NS group exhibit significant lung injury characterized by a high W/D (P < 0.01), accumulation of a large number of neutrophils in HE stain, low partial pressure of oxygen (PO2) and high lactate (Lac) (P<0.05 or P<0.01) in arterial blood. Compared with the NS group, DRPs treatment rats exhibit significantly reduced lung injury characterized by W/D reducing (P < 0.05), the reduction of neutrophil infiltration, increased PO2, decreased Lac (P<0.05, P<0.01). In addition, DRPs treatment obviously increases the burn-induced low velocity of flow of red cell in oblique ridge (P<0.01). Moreover, the survival time of burned rats can be improved by DRPs treatment (P < 0.05). Conclusion DRPs ameliorates burn-induced acute lung injury, the mechanism may be through improving the burn-induced microcirculation disorders.