Tissue-specific extravasation of albumin-bound Evans blue in hypothermic and rewarmed rats

Abstract

The effects of hypothermia and rewarming on endothelial integrity were examined in intestines, kidney, heart, gastrocnemius muscle, liver, spleen, and brain by measuring albumin-bound Evans blue loss from the vasculature. Ten groups of twelve rats, normothermic with no pentobarbital, normothermic sampled at 2, 3, or 4 h after pentobarbital, hypothermic to 20, 25, or 30 degrees C, and rewarmed from 20, 25, or 30 degrees C, were cooled in copper coils through which water circulated. Hypothermic rats were cooled to the desired core temperature and maintained there for 1 h; rewarmed rats were cooled to the same core temperatures, maintained there for 1 h, and then rewarmed. Following Evans blue administration, animals were euthanized with methoxyflurane, tissues removed, and Evans blue extracted. Because hypothermia and rewarming significantly decrease blood flow, organ-specific flow rates for hypothermic and rewarmed tissues were used to predict extravasation. Hypothermia decreased extravasation in tissues with continuous endothelium (brain, muscle) and increased it in tissues with discontinuous endothelium (liver, lung, spleen). All tissues exhibited significant (p < 0.05) differences from normothermic controls. These differences are attributed to a combination of anesthesia, flow, and (or) change in endothelial permeability, suggesting that appropriate choice of organ and temperature would facilitate testing pharmacological means of promoting return to normal perfusion.

Carnosine treatment largely prevents alterations of renal carnosine metabolism in diabetic mice

“…After 10 min, the mice were euthanized by CO 2 inhalation, blood samples were collected and the kidneys were removed, blotted dry, and weighed. The Evans blue dye was extracted from the kidney with 1 ml of formamide overnight at 65°C and measured spectrophotometrically at 620 nm (Ibla and Khoury 2006;Matthew et al 2002).…”

Effects of Hypothermia on Rat Reticuloendothelial Blood Clearance and Particulate Uptake

“…It employed a model that permitted simultaneous induction of whole body hypothermia to multiple rats (14). This extended the use of the rat in defining hypothermic pathophysiological events, which have previously included studies on cardiac function (18), blood flow (19) and tissue extravasation (13).…”

“…All hypothermia and REW groups had significantly lower liver PU than non-anesthetized, normothermic controls. Factors such as blood flow (19), blood vessel permeability (13) and the presence of anesthesia may have influenced these liver findings. Of these, anesthesia would normally be extrinsic to naturally occurring hypothermia.…”

Effect on vascular permeability of a self-etching adhesive system containing an antimicrobial quaternary ammonium polymer QAMP into subcutaneous tissue of rats

“…19 Considering that Evans Blue can pass through gap between endothelial cells as small as 7 nm, this stain also binds to albumin related to the exudative process. 20 Thus a spectrophotometric determination of Evans Blue stain accumulation is an easy procedure to estimate changes in vascular permeability. 17 The laser-Doppler flowmetric determination is a relatively new, noninvasive and painless method for measuring blood flow and erythrocyte content in tissues and organs.…”