Increased fatty acid oxidation in immature reperfused hearts -Effects of insulin and glucagon-

• Project/Area Number: 11670777
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Pediatrics
• Research Institution: Kyoto Prefectural University of Medicine
• Principal Investigator: ITOI Toshiyuki Kyoto Prefectural Universit of Medicine, Associate Professor, 医学部, 助教授 (10264780)
• Project Period (FY): 1999 – 2000
• Project Status: Completed (Fiscal Year 2000)
• Budget Amount: ¥3,600,000 (Direct Cost: ¥3,600,000); Fiscal Year 2000: ¥1,100,000 (Direct Cost: ¥1,100,000); Fiscal Year 1999: ¥2,500,000 (Direct Cost: ¥2,500,000)
• Keywords: immature heart / insulin / glucagon / fatty acid oxidation / reperfusion / malonyl-CoA / カルシウム / 再潅流障害

Research Abstract

Animal : Japanese white rabbit, two-week-old
Isolated working heart perfusion : 2O min normoxia-40 min ischemia-40 min reperfusion
Perfusion buffer : Krebs-Henselit (pH=7.4), including 1.25mM Ca^<2+>, 5.5mM glucose, 1.2mM ^<13>C-palmitate, 1.25mM lactate, 0.5mM acetoacetate.
Indication of cardiac function : heart rate x systolic pressure (double product, DP), cardiac output x systolic pressure (cardiac work, CW)
Myocardial ^<13>C-acetyl carnitine detection : Tandem mass
Myocardial CoA esters concentration : HPLC
Group : group 1 - no ischemia (40 min), insulin (40 U/ml) group 2 - no ischemia (40 min), glucagon (1 μg/ml) group 3 - reperfusion, insulin (40 U/ml) group 4 - reperfusion, glucagon (1 μg/ml)
RESULTS :
cardiac function (DP, CW) no ischemia : group 1 = group 2 reperfusion : group 3>group 4
palmitate oxidation no ischemia : group 1<group 2 reperfusion : group 3<group 4
tissue malonyl-CoA no ischemia : group 1>group 2 reperfusion : group 3>group 4
In reperfused immature hearts, glucagon may have detrimental effects on the recovery of contracrail function due to accelerate fatty acid oxidation.