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Systemic Clearance of Fluorescent Dextrans after Hemorrhage in Rats
Author(s) -
Carvalho Helena,
Woodruff Aleesha R,
Simmons Kristin L,
Pittman Roland N
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.975.13
Subject(s) - dextran , vascular permeability , chemistry , clearance rate , glycocalyx , permeability (electromagnetism) , dextran 70 , medicine , endocrinology , chromatography , biochemistry , membrane
An intact endothelial glycocalyx is associated with vascular homeostasis, and its disruption leads to increased vascular permeability. We evaluated the systemic clearance of macromolecules from the circulation after hemorrhage. We injected a dextran mixture (0.5ml of 1.2 mg/ml FITC‐labelled 500 kDa dextran (Dex‐500) and 0.5 ml of 2.5 mg/ml Texas Red‐labelled 40 kDa dextran (Dex‐40)) i.v. in anesthetized Sprague‐Dawley rats (250–350 g). Hemorrhage was induced by withdrawing 40% of blood volume over a 30 min period. After 30 min of stabilization at the end of hemorrhage, rats received the dextran mixture (1 ml/300 g rat). Blood samples were collected at 1, 5, 10, 15, 20 and 30 min and then centrifuged. Plasma fluorescence was analyzed in a luminescence spectrometer at 490/535 nm (ex/em) for Dex‐500 and 595/615 nm (ex/em) for Dex‐40. Hemorrhage led to a drop in arterial pressure from 110 ± 10 mmHg to 50 ± 8 mmHg. The clearance rate of Dex‐40 increased by 33% and Dex‐500 by 9% compared with the control group. Under control conditions Dex‐40/Dex‐500 clearance ratio was 1.36 and increased to 1.66 after hemorrhage; thus, the permeability to Dex‐40 increased more than the permeability to Dex‐500 following hemorrhage. The increased clearance rates of these macromolecules are consistent with degradation of the glycocalyx following hemorrhage, compared to control, based on its role as a permeability barrier to macromolecules. Support: HL079087 from NHLBI