title: Role of adenosine for reactive hyperemia in normal and stunned porcine myocardium.
abstract: The role of adenosine for reactive hyperemia in normal and stunned myocardium was examined in 16 open-chest barbiturate-anesthetized pigs. Interstitial adenosine concentration was reduced or enhanced by intracoronary infusion of adenosine deaminase or the nucleoside transport inhibitor R 75231, respectively. In normal myocardium, adenosine deaminase reduced volume of hyperemia (Doppler flowmetry) after a 30-s left anterior descending coronary artery (LAD) occlusion by 20% (6-34%; P < 0.05), whereas R 75231 increased volume of hyperemia by 15% (2-24%; P < 0.05). Adenosine deaminase reduced volume of hyperemia after a 2-min LAD occlusion by 27% (13-37%; P < 0.001), whereas R 75231 increased volume of hyperemia by 66% (53-159%; P < 0.001). Adenosine deaminase and R 75231 did not affect maximal hyperemia. Volume of hyperemia after a 2-min LAD occlusion was reduced in stunned myocardium (%systolic segment length shortening reduced by approximately 45%, ultrasonic technique) but not further altered by either adenosine deaminase or R 75231. These findings show that adenosine contributes to reactive hyperemia after 30-120 s of ischemia in normal myocardium and indicate that the reduced reactive hyperemia in stunned myocardium is due to reduced accumulation of adenosine during ischemia.
authors.affiliation: University of Oslo, Institute for Experimental Medical Research, Ullevål Hospital, Norway.
authors.forename: K A
authors.initials: KA
authors.lastname: Kirkebøen
authors.forename: G
authors.initials: G
authors.lastname: Aksnes
authors.forename: K
authors.initials: K
authors.lastname: Lande
authors.forename: A
authors.initials: A
authors.lastname: Ilebekk
mesh_terms: D000241:Adenosine / Q000378:metabolism*; D000243:Adenosine Deaminase / Q000494:pharmacology; D000818:Animals; D003327:Coronary Disease / Q000378:metabolism* / Q000503:physiopathology; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006940:Hyperemia / Q000378:metabolism*; D008297:Male; D015428:Myocardial Reperfusion Injury / Q000378:metabolism* / Q000503:physiopathology; D010879:Piperazines / Q000494:pharmacology; D012016:Reference Values; D013552:Swine
chemical_list: D010879:Piperazines; C072040:draflazine; D000243:Adenosine Deaminase; D000241:Adenosine