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DIABETES DOES NOT ALTER CONTRACTILE FUNCTION IN HIBERNATING MYOCARDIUM OF CONSCIOUS SWINE
Author(s) -
Sharma Sandeep,
Yoon SungHo,
Cook Jeffrey,
Saad Maged M.,
Eom Woosik,
Crystal George J.,
Kim SongJung
Publication year - 2010
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.24.1_supplement.601.1
Subject(s) - hibernating myocardium , medicine , inotrope , endocrinology , diabetes mellitus , glycogen , streptozotocin , cardiology , carbohydrate metabolism , glucose uptake , contraction (grammar) , metabolism , insulin , myocardial infarction , revascularization
It has been proposed that a shift to glucose metabolism is integral to development of hibernating myocardium (HM). We tested the hypothesis that diabetic hearts have impaired contractile function during hibernation. Fifteen swine were divided into control (CON; n=8) and streptozotocin (STZ)‐treated (100 mg/kg; n=7) groups. Animals were chronically instrumented to measure coronary blood flow (CBF) and regional wall thickening (WT). Aortic and coronary sinus blood samples were obtained so that myocardial glucose uptake (MGU) could be calculated. HM was induced by 6 repetitive episodes of 90‐min coronary stenosis (30% reduction in baseline CBF) followed by reperfusion every 12 h. Inotropic reserve was assessed with isoproterenol (ISO, 0.2 μg/kg/min, i.v.). Plasma glucose was elevated in STZ compared to CON. In CON, MGU was increased 2‐fold during hibernation compared to baseline, whereas MGU was not affected in STZ; glycogen deposition was prominent in CON but negligible in STZ. Nevertheless, decreases in WT in HM stabilized at a similar level in CON and STZ (−22% and −14%, respectively). Furthermore, ISO caused equivalent, substantial increases in WT in HM of CON and STZ. We conclude that 1) diabetes does not impair contractile function in HM, 2) augmented glucose metabolism is not an essential feature of HM, and 3) inotropic reserve of HM remains intact in diabetic hearts.