Decreased mesenteric blood flow in experimental multiple organ failure

Abstract Disorders of mucosal blood flow may contribute to gut barrier dysfunction in multiple organ failure (MOF). We evaluated alterations of mesenteric microcirculation in a rat model of MOF. Male Wistar rats received 1 mg/g body weight of zymosan A in 4 ml of mineral oil by intraperitoneal injection and were studied on Days 1, 3, and 5 following injection. A control group received no zymosan. The experimental group also received a fluid resuscitation regimen of 0.9 N saline subcutaneously equal to 0.1 ml/g body weight on the day of zymosan injection and 0.05 ml/g body weight daily thereafter. Day 1 animals tended toward a statistically significantly lower mean arterial pressure versus controls (86.6 ± 8 mm Hg versus 106 ± 5 mm Hg, F = 0.09 by ANOVA). Significant arteriolar vasoconstriction occurred on Days 1 and 3 versus control (70 ± 4 μm and 57 ± 8 μm versus 96 ± 3 μm, F = 0.0002). Laser doppler velocity, indicating red blood cell velocity, expressed as a percentage of control paralleled this vasoconstriction (70 ± 9 and 72 ± 7%, respectively). We conclude that mesenteric arteriolar vasoconstriction occurs accompanied by decreased red blood velocity. We believe that this is indicative of decreased mesenteric perfusion in this zymosan model of MOF and that survival to Day 5 is associated with a reversal of these microcirculatory changes.