Basal and adenosine-mediated protein flux from isolated coronary
arterioles.
Huxley, Virginia H., and Donna A. Williams.
Department of Physiology and Dalton Cardiovascular Research Center,
University of Missouri School of Medicine, Columbia, MO 65212
APStracts 3:0076H, 1996.
We have developed a new method to quantify solute flux per unit
surface area and concentration gradient () from arterioles isolated
from pig hearts. The apparent permeability (Ps) was assessed from
measures of for two proteins, a-lactalbumin ([alpha]-lactalb) and
porcine serum albumin (PSA), labeled with the fluorescent dye
tetramethyl rhodamine isothiocyanate (TRITC) at a mean hydrostatic
pressure of 16+/-1 cmH2O. Ps for [alpha]-lactalb was 16.5 +/-4.6 x10
-7 cm.s-1 (mean +/- SEM, N = 8), a value significantly higher than
PsPSA (7.1+/- 1.4 x10-7 cm.s-1, N = 11 P < 0.05)). Suffusion of
the arterioles (44 +/-10 [mu]m diameter, n=48) with 10-5 M adenosine
resulted in a 35% decrease in Psalactalb and 29% decrease in PsPSA.
Data from the present study are consistent with adenosine altering
arteriole solute flux independently from its ability to change
arteriolar caliber. One implication of these results is that changes
in coronary exchange capacity reflect not only changes in flow
through but also solute permeation from the microvasculature.
Received 14 November 1995; accepted in final form 7 February
1996.
APS Manuscript Number H1072-5.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 24 February 96