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Özkan Kuşcu Ö, Kuş M, İncekaş C, Özmete Ö, Ergenoğlu P, Yıldırım S, Torgay A, Haberal M. Relationship Between Perioperative Factors and Splenic Artery Steal Syndrome After Orthotopic Liver Transplant: A Retrospective Clinical Study. EXP CLIN TRANSPLANT 2023; 21:743-748. [PMID: 37885290 DOI: 10.6002/ect.2023.0160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2023]
Abstract
OBJECTIVES After orthotopic liver transplant, ischemia of biliary tract and graft loss may occur due to impaired hepatic arterial blood flow. This situation with hypersplenism and impaired hepatic arterial blood flowis defined as splenic artery steal syndrome.The aim of this study was to investigate the relationship between perioperative factors and splenic artery steal syndrome in orthotopic liver transplant patients. MATERIALS AND METHODS Forty-five patients who underwent orthotopic liver transplant between 2014 and 2022 were included in the study. The data for the patients were obtained from the hospital database, including the intraoperative anesthesiology and postoperative intensive care records. RESULTS Eleven patients were diagnosed with splenic artery steal syndrome. Patients with splenic artery steal syndrome had higher need for intraoperative vasopressor agents (P = .016) and exhibited lower intraoperative urine output (P = .031). In the postoperative intensive care follow-up, patients with splenic artery steal syndrome had higher levels of C-reactive protein during the first 48 hours (P = .030). CONCLUSIONS Intraoperative administration of vasopressor drugs, low urine output, and early postoperative high C-reactive protein levels were associated with the development of splenic artery steal syndrome in patients undergoing orthotopic liver transplant. Future studies should focus on investigation of biomarkers associated systemic hypoperfusion that may contribute to the development of splenic artery steal syndrome.
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Affiliation(s)
- Özlem Özkan Kuşcu
- From the Department of Anesthesiology and Reanimation, Baskent University Faculty of Medicine, Adana, Turkey
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Isoform-specific regulation of the Na+ -K+ pump by adenosine in guinea pig ventricular myocytes. Acta Pharmacol Sin 2009; 30:404-12. [PMID: 19305421 DOI: 10.1038/aps.2009.26] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
AIM The present study investigated the effect of adenosine on Na(+)-K(+) pumps in acutely isolated guinea pig (Cavia sp.) ventricular myocytes. METHODS The whole-cell, patch-clamp technique was used to record the Na(+)-K(+) pump current (I(p)) in acutely isolated guinea pig ventricular myocytes. RESULTS Adenosine inhibited the high DHO-affinity pump current (I(h)) in a concentration-dependent manner, which was blocked by the selective adenosine A(1) receptor antagonist DPCPX and the general protein kinase C (PKC) antagonists staurosporine, GF 109203X or the specific delta isoform antagonist rottlerin. In addition, the inhibitory action of adenosine was mimicked by a selective A(1) receptor agonist CCPA and a specific activator peptide of PKC-delta, PP114. In contrast, the selective A(2A) receptor agonist CGS21680 and A(3) receptor agonist Cl-IB-MECA did not affect I(h). Application of the selective A(2A) receptor antagonist SCH58261 and A(3) receptor antagonist MRS1191 also failed to block the effect of adenosine. Furthermore, H89, a selective protein kinase A (PKA) antagonist, did not exert any effect on adenosine-induced I(h) inhibition. CONCLUSION The present study provides the electrophysiological evidence that adenosine can induce significant inhibition of I(h) via adenosine A(1) receptors and the PKC-delta isoform.
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Bassingthwaighte JB, Chizeck HJ, Atlas LE. Strategies and Tactics in Multiscale Modeling of Cell-to-Organ Systems. PROCEEDINGS OF THE IEEE. INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS 2006; 94:819-830. [PMID: 20463841 PMCID: PMC2867355 DOI: 10.1109/jproc.2006.871775] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Modeling is essential to integrating knowledge of human physiology. Comprehensive self-consistent descriptions expressed in quantitative mathematical form define working hypotheses in testable and reproducible form, and though such models are always "wrong" in the sense of being incomplete or partly incorrect, they provide a means of understanding a system and improving that understanding. Physiological systems, and models of them, encompass different levels of complexity. The lowest levels concern gene signaling and the regulation of transcription and translation, then biophysical and biochemical events at the protein level, and extend through the levels of cells, tissues and organs all the way to descriptions of integrated systems behavior. The highest levels of organization represent the dynamically varying interactions of billions of cells. Models of such systems are necessarily simplified to minimize computation and to emphasize the key factors defining system behavior; different model forms are thus often used to represent a system in different ways. Each simplification of lower level complicated function reduces the range of accurate operability at the higher level model, reducing robustness, the ability to respond correctly to dynamic changes in conditions. When conditions change so that the complexity reduction has resulted in the solution departing from the range of validity, detecting the deviation is critical, and requires special methods to enforce adapting the model formulation to alternative reduced-form modules or decomposing the reduced-form aggregates to the more detailed lower level modules to maintain appropriate behavior. The processes of error recognition, and of mapping between different levels of model complexity and shifting the levels of complexity of models in response to changing conditions, are essential for adaptive modeling and computer simulation of large-scale systems in reasonable time.
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Bassingthwaighte JB, Chizeck HJ, Atlas LE, Qian H. Multiscale modeling of cardiac cellular energetics. Ann N Y Acad Sci 2005; 1047:395-424. [PMID: 16093514 PMCID: PMC2864600 DOI: 10.1196/annals.1341.035] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Multiscale modeling is essential to integrating knowledge of human physiology starting from genomics, molecular biology, and the environment through the levels of cells, tissues, and organs all the way to integrated systems behavior. The lowest levels concern biophysical and biochemical events. The higher levels of organization in tissues, organs, and organism are complex, representing the dynamically varying behavior of billions of cells interacting together. Models integrating cellular events into tissue and organ behavior are forced to resort to simplifications to minimize computational complexity, thus reducing the model's ability to respond correctly to dynamic changes in external conditions. Adjustments at protein and gene regulatory levels shortchange the simplified higher-level representations. Our cell primitive is composed of a set of subcellular modules, each defining an intracellular function (action potential, tricarboxylic acid cycle, oxidative phosphorylation, glycolysis, calcium cycling, contraction, etc.), composing what we call the "eternal cell," which assumes that there is neither proteolysis nor protein synthesis. Within the modules are elements describing each particular component (i.e., enzymatic reactions of assorted types, transporters, ionic channels, binding sites, etc.). Cell subregions are stirred tanks, linked by diffusional or transporter-mediated exchange. The modeling uses ordinary differential equations rather than stochastic or partial differential equations. This basic model is regarded as a primitive upon which to build models encompassing gene regulation, signaling, and long-term adaptations in structure and function. During simulation, simpler forms of the model are used, when possible, to reduce computation. However, when this results in error, the more complex and detailed modules and elements need to be employed to improve model realism. The processes of error recognition and of mapping between different levels of model form complexity are challenging but are essential for successful modeling of large-scale systems in reasonable time. Currently there is to this end no established methodology from computational sciences.
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Kellen MR, Bassingthwaighte JB. Transient transcapillary exchange of water driven by osmotic forces in the heart. Am J Physiol Heart Circ Physiol 2003; 285:H1317-31. [PMID: 12738617 PMCID: PMC3496751 DOI: 10.1152/ajpheart.00587.2002] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Osmotic transient responses in organ weight after changes in perfusate osmolarity have implied steric hindrance to small-molecule transcapillary exchange, but tracer methods do not. We obtained osmotic weight transient data in isolated, Ringer-perfused rabbit hearts with NaCl, urea, glucose, sucrose, raffinose, inulin, and albumin and analyzed the data with a new anatomically and physicochemically based model accounting for 1) transendothelial water flux, 2) two sizes of porous passages across the capillary wall, 3) axial intracapillary concentration gradients, and 4) water fluxes between myocytes and interstitium. During steady-state conditions approximately 28% of the transcapillary water flux going to form lymph was through the endothelial cell membranes [capillary hydraulic conductivity (Lp) = 1.8 +/- 0.6 x 10-8 cm. s-1. mmHg-1], presumably mainly through aquaporin channels. The interendothelial clefts (with Lp = 4.4 +/- 1.3 x 10-8 cm. s-1. mmHg-1) account for 67% of the water flux; clefts are so wide (equivalent pore radius was 7 +/- 0.2 nm, covering approximately 0.02% of the capillary surface area) that there is no apparent hindrance for molecules as large as raffinose. Infrequent large pores account for the remaining 5% of the flux. During osmotic transients due to 30 mM increases in concentrations of small solutes, the transendothelial water flux was in the opposite direction and almost 800 times as large and was entirely transendothelial because no solute gradient forms across the pores. During albumin transients, gradients persisted for long times because albumin does not permeate small pores; the water fluxes per milliosmolar osmolarity change were 200 times larger than steady-state water flux. The analysis completely reconciles data from osmotic transient, tracer dilution, and lymph sampling techniques.
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Affiliation(s)
- Michael R Kellen
- Department of Bioengineering, University of Washington, Seattle, WA 98195-7962, USA
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Richmond KN, Tune JD, Gorman MW, Feigl EO. Role of K(ATP)(+) channels and adenosine in the control of coronary blood flow during exercise. J Appl Physiol (1985) 2000; 89:529-36. [PMID: 10926635 DOI: 10.1152/jappl.2000.89.2.529] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The present study was designed to examine the role of ATP-sensitive potassium (K(ATP)(+)) channels during exercise and to test the hypothesis that adenosine increases to compensate for the loss of K(ATP)(+) channel function and adenosine inhibition produced by glibenclamide. Graded treadmill exercise was used to increase myocardial O(2) consumption in dogs before and during K(ATP)(+) channel blockade with glibenclamide (1 mg/kg iv), which also blocks adenosine mediated coronary vasodilation. Cardiac interstitial adenosine concentration was estimated from arterial and coronary venous values by using a previously tested mathematical model (Kroll K and Stepp DW. Am J Physiol Heart Circ Physiol 270: H1469-H1483, 1996). Coronary venous O(2) tension was used as an index of the balance between O(2) delivery and myocardial O(2) consumption. During control exercise, myocardial O(2) consumption increased approximately 4-fold, and coronary venous O(2) tension fell from 19 to 14 Torr. After K(ATP)(+) channel blockade, coronary venous O(2) tension was decreased below control vehicle values at rest and during exercise. However, during exercise with glibenclamide, the slope of the line of coronary venous O(2) tension vs. myocardial O(2) consumption was the same as during control exercise. Estimated interstitial adenosine concentration with glibenclamide was not different from control vehicle and was well below the level necessary to overcome the 10-fold shift in the adenosine dose-response curve due to glibenclamide. In conclusion, K(ATP)(+) channel blockade decreases the balance between resting coronary O(2) delivery and myocardial O(2) consumption, but K(ATP)(+) channels are not required for the increase in coronary blood flow during exercise. Furthermore, interstitial adenosine concentration does not increase to compensate for the loss of K(ATP)(+) channel function.
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Affiliation(s)
- K N Richmond
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle 98195-7290, USA
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Tune JD, Richmond KN, Gorman MW, Olsson RA, Feigl EO. Adenosine is not responsible for local metabolic control of coronary blood flow in dogs during exercise. Am J Physiol Heart Circ Physiol 2000; 278:H74-84. [PMID: 10644586 DOI: 10.1152/ajpheart.2000.278.1.h74] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The purpose of this investigation was to quantitatively evaluate the role of adenosine in coronary exercise hyperemia. Dogs (n = 10) were chronically instrumented with catheters in the aorta and coronary sinus, and a flow probe on the circumflex coronary artery. Cardiac interstitial adenosine concentration was estimated from arterial and coronary venous plasma concentrations using a previously tested mathematical model. Coronary blood flow, myocardial oxygen consumption, heart rate, and aortic pressure were measured at rest and during graded treadmill exercise with and without adenosine receptor blockade with either 8-phenyltheophylline (8-PT) or 8-p-sulfophenyltheophylline (8-PST). In control vehicle dogs, exercise increased myocardial oxygen consumption 4.2-fold, coronary blood flow 3.8-fold, and heart rate 2.5-fold, whereas mean aortic pressure was unchanged. Coronary venous plasma adenosine concentration was little changed with exercise, and the estimated interstitial adenosine concentration remained well below the threshold for coronary vasodilation. Adenosine receptor blockade did not significantly alter myocardial oxygen consumption or coronary blood flow at rest or during exercise. Coronary venous and estimated interstitial adenosine concentration did not increase to overcome the receptor blockade with either 8-PT or 8-PST as would be predicted if adenosine were part of a high-gain, negative-feedback, local metabolic control mechanism. These results demonstrate that adenosine is not responsible for local metabolic control of coronary blood flow in dogs during exercise.
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Affiliation(s)
- J D Tune
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, Washington 98195, USA
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Abstract
Adenosine (Ado) is a naturally occurring compound that has several important cardiovascular actions, including activation of ATP-sensitive K(+) channels in vascular smooth muscle, vasorelaxation, and an effect to alter glucose metabolism of cardiac muscle. The metabolic effects of Ado on vascular smooth muscle have not been defined and were examined in this study. Porcine carotid artery strips were incubated in the presence and absence of 0.5 mM Ado. Compared with the control, Ado had no effect on glucose uptake, glucose oxidation, or fatty acid (octanoate) oxidation. Ado suppressed glycolysis but enhanced glycogen synthesis. Relative to the rate of glycolysis, Ado increased lactate production. Ado stimulated O(2) consumption by 52 +/- 10%, altered the activities of the tricarboxylic acid cycle and malate-aspartate shuttle, and increased the content of ATP, ADP, AMP, and phosphocreatine. Alteration in the metabolic variables by Ado could not be attributed to diminished energy requirements of reduced resting muscle tone of the arterial strips. Relaxation of the arterial strips in response to Ado were abolished in arteries incubated under hypoxic conditions (95% N(2)-5% CO(2)). Hypoxia was associated with increased ADP content. It is concluded that Ado affected glucose metabolism indirectly. The metabolic and energetic effects of 0.5 mM Ado are mediated by alterations in the concentrations of AMP, ATP, and phosphorylation potential (ATP/ADP).
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Affiliation(s)
- J T Barron
- Section of Cardiology, Department of Internal Medicine, Rush Medical College, Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois 60612, USA.
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Kroll K, Decking UK, Dreikorn K, Schrader J. Rapid turnover of the AMP-adenosine metabolic cycle in the guinea pig heart. Circ Res 1993; 73:846-56. [PMID: 8403255 DOI: 10.1161/01.res.73.5.846] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The intracellular flux rate through adenosine kinase (adenosine-->AMP) in the well-oxygenated heart was investigated, and the relation of the AMP-adenosine metabolic cycle (AMP<-->adenosine) to transmethylation (S-adenosylhomocysteine [SAH]-->adenosine) and coronary flow was determined. Adenosine kinase was blocked in isolated guinea pig hearts by infusion of iodotubercidin in the presence of the adenosine deaminase blocker erythro-9-(2-hydroxy-3-nonyl)adenine (5 mumol/L). Iodotubercidin (1 nmol/L to 4 mumol/L) caused graded increases in venous effluent concentrations of adenosine, from 8 +/- 3 to 145 +/- 32 nmol/L (mean +/- SEM, n = 3), and in coronary flow, which increased to maximal levels. Flow increases were completely abolished by adenosine deaminase (5 to 10 U/mL). Interstitial adenosine concentrations, estimated using a mathematical model, increased from 22 nmol/L during control conditions to 420 nmol/L during maximal vasodilation. The possibility that iodotubercidin caused increased venous adenosine by interfering with myocardial energy metabolism was ruled out in separate 31P nuclear magnetic resonance experiments. To estimate total normoxic myocardial production of adenosine (AMP-->adenosine<--SAH), the time course of coronary venous adenosine release was measured during maximal inhibition of adenosine kinase with 30 mumol/L iodotubercidin. Adenosine release increased more than 15-fold over baseline, reaching a new steady-state value of 3.4 +/- 0.3 nmol.min-1 x g-1 (n = 5) after 4 minutes. In parallel experiments, the relative roles of AMP hydrolysis and transmethylation (SAH hydrolysis) were determined, using adenosine dialdehyde (10 mumol/L) to block SAH hydrolase. In these experiments, adenosine release increased to similar levels of 3.4 +/- 0.5 nmol.min-1 x g-1 (n = 6) during inhibition of adenosine deaminase and adenosine kinase. It is concluded that (1) maximal increases in coronary flow are elicited by increases in interstitial adenosine concentration to approximately 400 nmol/L, (2) more than 90% of the adenosine produced in the heart is normally rephosphorylated to AMP without escaping into the venous effluent, (3) AMP hydrolysis is the dominant pathway for cardiac adenosine production under normoxic conditions, and (4) the high rate of adenosine salvage is due to rapid turnover of a metabolic cycle between AMP and adenosine. Rapid cycling may serve to amplify the relative importance of AMP hydrolysis over transmethylation in controlling cytosolic adenosine concentrations.
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Affiliation(s)
- K Kroll
- Center for Bioengineering, University of Washington, Seattle
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Kroll K, Schrader J. Myocardial adenosine stimulates release of cyclic adenosine monophosphate from capillary endothelial cells in guinea pig heart. Pflugers Arch 1993; 423:330-7. [PMID: 8391684 DOI: 10.1007/bf00374413] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Activation of coronary endothelial cell adenylate cyclase was studied in the isolated guinea pig heart by prelabelling endothelial adenine nucleotides using intracoronary infusion of [3H]-adenosine, and measuring the coronary efflux of [3H]-cyclic adenosine monophosphate (cAMP). Hypoxia (30% O2) caused a 4-fold increase in coronary release of [3H]-cAMP, which was decreased by 63% by infusion of the adenosine receptor antagonist, theophylline (50 microM). During normoxic control conditions, degrading adenosine to non-vasoactive inosine by intracoronary infusion of adenosine deaminase (1.7 U/ml) caused a 20% decrease in the release of [3H]-cAMP. The effect of adenosine deaminase was reversed by a specific enzyme inhibitor erythro-9-(2-hydroxy-3-nonyl)adenine hydrochloride. Coronary efflux of [3H]-cAMP during intracoronary infusion of 1 microM adenosine triphosphate (ATP), adenosine diphosphate or adenosine monophosphate (AMP) (plus adenosine deaminase 8 U/ml) was only 13% of that due to 1 microM adenosine. Adenosine receptor blockers theophylline and CGS 15943A caused equivalent inhibition of the coronary vasodilator actions of adenosine and ATP. Intracoronary infusion of prostaglandin E1 and the beta 2-adrenergic agonist procaterol caused parallel, dose-dependent increases in coronary conductance and the venous release of [3H]-cAMP. It is concluded that (1) under both normoxic and hypoxic conditions, adenosine formed by the heart may activate endothelial cell adenylate cyclase via membrane adenosine receptors, (2) coronary receptors for adenosine and ATP share common ligand affinities but ATP receptors are not coupled to adenylate cyclase, and (3) other vasodilators known to activate endothelial adenylate cyclase in vitro cause parallel increases in coronary conductance and adenylate cyclase activity in the beating heart.
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Affiliation(s)
- K Kroll
- Center for Bioengineering, University of Washington, Seattle 98195
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Kroll K, Deussen A, Sweet IR. Comprehensive model of transport and metabolism of adenosine and S-adenosylhomocysteine in the guinea pig heart. Circ Res 1992; 71:590-604. [PMID: 1499107 DOI: 10.1161/01.res.71.3.590] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Regulation of blood flow and mitochondrial respiration in the heart would be clarified by improved knowledge of interstitial concentrations and cellular production rates of adenosine; however, these variables cannot be measured directly. To interpret indexes that are available, a comprehensive mathematical model was developed, based on a large body of experimental data. The model describes most of the important pathways of capillary-tissue transport and cellular metabolism of adenosine in the guinea pig heart. It includes capillary flow, solute transport between tissue regions, nonlinear enzyme kinetics for adenosine kinase and adenosine deaminase, and reversible biunireactant kinetics for S-adenosylhomocysteine hydrolase in cardiomyocytes and endothelial cells, intracellular production of adenosine via AMP hydrolysis and transmethylation, and extracellular production of adenosine. A single set of parameter values for the model was obtained in the first stage of the analysis by taking certain values directly from published sources, other values were subject to specific constraints, and other values were determined by parameter optimization. The effects of flow and endothelial metabolism on the relation between interstitial and venous adenosine concentrations were determined. The relation between myocardial adenosine production rate and S-adenosylhomocysteine accumulation in the presence of excess homocysteine was estimated. In the second stage of the analysis, the model was used to investigate the mechanism of myocardial adenosine production, without changing the parameter values. Cellular adenosine production rates were estimated by fitting measurements of venous adenosine release obtained during altered energetic conditions in experiments by different investigators. The original results showed a dissociation between measurements of cytosolic AMP concentrations and venous adenosine release. It is concluded that 1) it is essential to account for the effect of flow on interstitial and venous adenosine concentrations, since decreased flow may produce effects outwardly resembling inhibition of the enzyme 5'-nucleotidase, 2) adenosine concentrations in epicardial transudate are not in equilibrium with interstitial fluid, and 3) the rate of cellular adenosine production increases monotonically with free cytosolic concentrations of AMP during a variety of alterations in energy balance of the guinea pig heart.
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Affiliation(s)
- K Kroll
- Center for Bioengineering, University of Washington, Seattle 98195
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