J.Jpn. Surg. Soc.. 82(2): 139-148, 1981
Original article
BASIC STUDY OF MYOCARDIAL PROTECTION ON CYCLIC AMP
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Department of Surgery, Showa University School of Medicine Tsunahito Yoshizawa, Toshihiro Takaba, Mototoshi Yamashiro, Hiroshi Maeda, Jun-ichi Ishii |
Rat’s heart placed under various ischemic conditions, section of the left ventricular myocardium was taken 30, 60, 120, 180 and 240 minutes after aortic occlusion, incubated by Krebs-Henseleit solution containing 10-7 M isoproterenol and 10-2 M theophylline, then cyclic AMP concentration was determined.
Under normothermic anoxic arrest, concentration of cyclic AMP which was determined after 30 minutes of aortic cross clamping revealed 40% of normal value and gradually decreased untill 13% in 240 minutes. Rat’s coronary bed was washed out, by 37℃ warm saline just after aortic cross clamping, concentration of cyclic AMP showed 75% of normal value and it was 90% by 20℃ and 4 °C cold saline after 30 minutes of aortic occlusion, but they decreased in 240 minutes as same as normothermic anoxic arrest. Cardioplegic solution based Hartman’s solution containing K+30 mEq/L, 380 mOsm/L, pH 8, was injected every 30 minutes after aortic cross clamping, concentration of cyclic AMP which was determined after 30 minutes of revealed 110%, of normal value gradually decreased untill 47% in 240 minutes of normal value. High concentration of potassium (60 mEq/L) cardioplegic solution and high osmolarity (500 mOsm/L) cardioplegic solution led reduction in cyclic AMP as same as normothermic anoxic arrest.
These results suggested that washed out of coronary bed by cold cardioplegic solution during aortic cross clamping improved myocardial protection, it was evaluated by cyclic AMP.
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