Organ-Specific Extravasation of Albumin-Bound Evans Blue During Nonresuscitated Hemorrhagic Shock in Rats

Abstract

Shock-induced enhanced capillary permeability is associated with alterations in the interstitial matrix composition and contributes to organ damage. This study was designed to evaluate albumin extravasation in various organ tissues during severe, hemorrhagic shock without fluid resuscitation and reperfusion. Target value of hemorrhagic shock was a reduction of cardiac output (CO) by 50% induced by removal of blood. Twelve anesthetized Sprague-Dawley rats (260-325 g) kept under continuous hemodynamic monitoring were randomly assigned to a group of hemorrhagic shock (n = 6) and a control group of normovolemic animals (n = 6). After 30 min of shock 50 mg/kg b.w. Evans blue (EB) was injected intravenously followed by an incubation period of 20 min. Exsanguination and wash out of the intravascular space was performed by a pressure-controlled perfusion with heparinized saline before harvesting organs to quantify albumin-bound EB extravasation. We found that withdrawal of 4.7 +/- 0.4 mL (mean, +/-SEM) blood, which accounts for 21.1% of the calculated total blood volume, resulted in a reduction of CO from 36.1 +/- 3.1 to 19.4 +/- 2.7 mL/min. Simultaneously, MAP decreased from 98 +/- 6 to 40 +/- 1 mmHg. In hemorrhaged rats, the interstitial concentration of EB in lung and kidney was significantly higher than observed in intact animals, whereas heart, spleen, liver, ileum, skeletal muscle, and skin showed no significant microvascular damage. We conclude that despite the absence of fluid resuscitation and reperfusion, microvascular damage in lung and kidney is evident within the first thirty minutes of hemorrhagic shock.

Ulinastatin Improves Pulmonary Function in Severe Burn-Induced Acute Lung Injury by Attenuating Inflammatory Response

“…Evans blue (EB, 50 mg/kg body weight) was injected through the tail vein, followed by 3 mL of 0.9% saline solution for intravenous infusion. The circulating dye was washed using a perfusion system with 25 mL of heparinized 0.9% saline, as described by Schumacher et al 9 After the animals were killed, a lung was removed, weighed, and placed in formamide solution for extracting EB. After 48 hours, the supernatants were collected and the absorbance was measured at 620 nm using a spectrophotometer (SmartSpec Plus; BioRad, Hercules, CA) relative to a standard curve of EB.…”

Endothelial Cysteinyl Leukotriene 2 Receptor Expression Mediates Myocardial Ischemia-Reperfusion Injury

“…A 23-gauge needle was inserted into the apex of the left ventricle and the mouse was perfused retrogradely at 40 mmHg with 5.85 ml/100 g of 0.9% NaCl containing 100 U/ml heparin as described previously. 28 The LAD was then religated and Evans blue dye was perfused as above to delineate the risk area, which was then dissected from the remaining myocardial tissue, weighed, and placed in individual tubes. The radioactivity in the blood, nonrisk area, and risk area were counted separately using a gamma counter (Beckman Instruments, Irvine, CA).…”

Attenuating Burn Wound Inflammatory Signaling Reduces Systemic Inflammation and Acute Lung Injury

“…At times 6 and 12 h postinjury, animals were exsanguinated by incision of the right atrium. Systemic circulating dye was eluted, inserting a 20G cannula through the apex of the left ventricle into the ascending aorta and perfusing a total volume of four times the calculated blood volume (7.46 ml/100 g), as described previously (20), using heparinized (100 U/ml) 0.9% saline and a pressurecontrolled perfusor pump (B. Braun Medical) at constant flow rate. Pulmonary intravascular dye was eluted via pulmonary artery cannulation and perfusion with 5 ml of heparinized saline.…”