Role of neutrophils in endotoxin-mediated microvascular injury in hamsters.
The purpose of this study was to examine the role of circulating neutrophils in endotoxin-induced increase in microvascular permeability in vivo. Fifteen hamsters were anesthetized, and a plastic chamber was placed in each cheek pouch to observe the microvasculature. Fluorescein-labeled dextran (FITC-D, 150 kDa) was injected intravenously, and changes in leaky sites and FITC-D clearance were measured in three groups: control (saline, n = 4), endotoxin suffusion (n = 6), and endotoxin suffusion after neutropenia induction (n = 5). We found a significant increase in leaky sites and FITC-D clearance with endotoxin (45 +/- 18/cm2 and 20 +/- 6 x 10(-6) ml/min, respectively; mean +/- SD, P less than 0.05) in comparison to control (7 +/- 6/cm2 and 7 +/- 5 x 10(-6) ml/min) and endotoxin suffusion in neutropenic animals (19 +/- 11/cm2 and 12 +/- 4 x 10(-6) ml/min). There was a significant correlation between the number of leaky sites and FITC-D clearance (r = 0.91, P less than 0.01) and between the number of circulating neutrophils and FITC-D clearance (r = 0.87, P less than 0.01). We conclude that endotoxin-mediated increase in microvascular permeability in the peripheral circulation is dependent in part on circulating neutrophils.
Matsuda
T
T
Department of Internal Medicine, University of Nebraska Medical Center, Omaha 68198-2465.
Rubinstein
I
I
Robbins
R A
RA
Koyama
S
S
Joyner
W L
WL
Rennard
S I
SI
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002199:Capillary Permeability / Q000187:drug effects; D006224:Cricetinae; D003911:Dextrans; D004731:Endotoxins / Q000633:toxicity*; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives*; D005452:Fluoresceins; D007958:Leukocyte Count; D008297:Male; D008647:Mesocricetus; D008833:Microcirculation / Q000503:physiopathology*; D009061:Mouth Mucosa / Q000166:cytology / Q000187:drug effects; D009503:Neutropenia / Q000139:chemically induced / Q000503:physiopathology; D009504:Neutrophils / Q000502:physiology*; D014652:Vascular Diseases / Q000139:chemically induced* / Q000503:physiopathology
D003911:Dextrans; D004731:Endotoxins; D005452:Fluoresceins; C015219:fluorescein isothiocyanate dextran; D016650:Fluorescein-5-isothiocyanate