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Relationship between H 2 O 2 and A 2 adenosine receptors in reactive hyperemia in isolated mouse heart
Author(s) -
Sanjani Maryam Sharifi,
Teng Bunyen,
Tilley Stephen,
Ledent Catherine,
Mustafa S. Jamal
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.814.14
Reactive hyperemia (RH) is a regulatory response to temporary blood flow interruption where metabolic regulators play an important role. Adenosine, released due to increased heart O 2 consumption/supply, exerts its effects through its 4 receptors (AR). We have shown the involvement of A 2 ARs (A 2A and A 2B ) in coronary flow (CF) regulation while their role in RH is yet to be elucidated. Our objective was to elucidate the roles of A 2 ARs in CF responses to RH. Using Langendorff, coronary RH in wild type (WT) and knockouts (KO) for A 2A , A 2B , and A 2A/2B were assessed by a 15s inflow occlusion. Repayment/debt area (RP/DA) of A 2A and A 2A/2B KO but not A 2B KO, were significantly less than WT. Furthermore, since H 2 O 2 is reported as the EDHF we wanted to test its involvement in A 2 AR‐induced effects using Catalase (CAT). CAT significantly reduced the WT RP/DA compared to WT alone while not affecting the A 2A KO RP/DA compared to its control. We propose that A 2A AR plays a major role in RH through release of H 2 O 2 . HL027339 , HL094447 , HL071802 , T32 HL090610ml/min.g Resting Flow DA Peak RPA RP/DAWT 19.8±2 79.2±8.2 42.1±4.9 32.6±2.7 0.41±0.02 A 2A KO 20.2±4.4 81±17.6 43.4±4.8 30.8±4.8 0.38±0.03 * A 2B KO 19.5±2.6 78±10.5 43.1±2.6 31.4±3.6 0.4±0.02 A 2A/2B KO 18.4±1.7 73.8±6.7 41.6±3.4 28.6±1.8 * 0.38±0.01 * WT+CAT 21.4±7.5 85.7±29.8 39.2±8.1 30.2±9.7 0.36±0.04 * A 2A KO+CAT 16.9±2.4 * 67.8±9.7 * 39.6±3.9 26.5±4.1 * 0.39±0.01 ** p<0.05 compared to WT