|
|
||||||||
AJP - Heart and Circulatory Physiology, Vol 259, Issue 3 772-H783, Copyright © 1990 by American Physiological Society
ARTICLES |
D. E. Mohrman and L. J. Heller
Department of Physiology, University of Minnesota, Duluth 55812.
Transcapillary adenosine transport was studied in isolated guinea pig and rat hearts perfused with a colloid-free solution. High-performance liquid chromatography techniques were used to measure adenosine concentration of venous and interstitial (epicardial surface) fluid during steady-state perfusion with various concentrations of adenosine. A mathematical model was used to analyze these data to obtain estimates of the following parameters of transcapillary adenosine transport: PSg, permeability-surface area product for adenosine movement through interendothelial cell channels; PSecl, permeability-surface area product for adenosine movement through the luminal plasma membrane of endothelial cells; and Gec, clearance rate constant for endothelial cell metabolism and/or sequestration of adenosine. In both guinea pig and rat hearts, PSg was estimated to be less than or equal to 3 ml.min-1.g-1. Estimates of PSecl and Gec of guinea pig hearts (7.2 +/- 0.4 and 230 +/- 157 ml.min-1.g-1) were significantly less than those of rat hearts (66 +/- 11 and 2,490 +/- 1,360 ml.min-1.g-1). That PSecl is greater than PSg in both species indicates that endothelial cells represent an important pathway for transcapillary adenosine transport. That Gec is much greater than PSecl in both species implies that endothelial cells act as a sink for adenosine from surrounding areas. Our results indicate that endothelium is a stronger sink for adenosine in rat hearts than in guinea pig hearts. Inosine infusion (10(-4)M) had little effect on the estimated PSecl and Gec in guinea pig hearts but reduced these parameters several-fold in rat hearts, suggesting that different transport mechanisms for adenosine exist in endothelia of guinea pig and rat hearts.
This article has been cited by other articles:
![]() |
T. H. Adair Growth regulation of the vascular system: an emerging role for adenosine Am J Physiol Regulatory Integrative Comp Physiol, August 1, 2005; 289(2): R283 - R296. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. M. Schwartz, T. R. Bukowski, J. H. Revkin, and J. B. Bassingthwaighte Cardiac endothelial transport and metabolism of adenosine and inosine Am J Physiol Heart Circ Physiol, September 1, 1999; 277(3): H1241 - H1251. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Srinivas, J. C. Shryock, D. M. Dennis, S. P. Baker, and L. Belardinelli Differential A1 Adenosine Receptor Reserve for Two Actions of Adenosine on Guinea Pig Atrial Myocytes Mol. Pharmacol., October 1, 1997; 52(4): 683 - 691. [Abstract] [Full Text] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |