AJP - Heart and Circulatory Physiology, Vol 253, Issue 6 1586-H1595, Copyright © 1987 by American Physiological Society
Modulation of macromolecular permeability by immune-complexes and a beta-adrenoceptor stimulant
S. W. Adamski, J. J. Langone and G. J. Grega
Department of Medicine, Baylor College of Medicine, Houston 77030.
The suffused, noneverted cheek pouch of ovalbumin (OA)-immunized hamsters
was employed to study changes in vascular permeability utilizing intravital
light microscopy and direct measurements of plasma to suffusate tracer
efflux. Suffusion of the cheek pouches of immunized animals with OA for 10
min stimulated the formation of focal venular fluorescein isothiocyanate
dextran (FITC-D, 70,000 Da) leakage sites and produced increases in the
plasma to suffusate FITC-D efflux resulting in marked increases in
concentration of FITC-D in suffusate ([FITC-D]s). The intravenous injection
of the FITC-D 15 to 60 min after the start of the OA suffusion failed to
reveal the formation of vascular FITC-D leakage sites or increases in
[FITC-D]s. In contrast, the intravenous injection of the tracer at the
start or 10 min after the start of the OA suffusion revealed the formation
of venular FITC-D leakage sites and marked increases in [FITC-D]s.
Treatment with diphenhydramine or isoproterenol completely inhibited the
antigen-stimulated formation of venular FITC-D leakage sites and increases
in [FITC-D]s. It is concluded that antigen-antibody reactions resulting in
the production of immune complexes trigger immediate increases in the
plasma to suffusate FITC-D clearance via the formation of venular FITC-D
leakage sites subsequent to the release of endogenous histamine. The
increase in venular permeability is marked but transient, lasting
approximately 10 min, and is subject to inhibition by either
diphenhydramine or isoproterenol.
