Involvement of Adenosine in Cardioprotective Effect of Catecholamine Preconditioning in Ischemia-Reperfused Heart of Rat

• 영문명: Involvement of Adenosine in Cardioprotective Effect of Catecholamine Preconditioning in Ischemia-Reperfused Heart of Rat
• 발행기관: 대한생리학회-대한약리학회
• 저자명: Young-hoon Kim Chan-hyung Kim Gi-tae Kim In-kyu Kim Jong-wan Park Myung-suk Kim
• 간행물 정보: 『The Korean Journal of Physiology & Pharmacology』제2권 제6호, 753~761쪽, 전체 9쪽
• 주제분류: 의약학 > 의학일반
• 파일형태: PDF
• 발행일자: 1998.01.01

영문 초록

Preconditioning of a heart with small doses of catecholamines induces a tolerance against the subsequent lethal ischemia. The present study was performed to find a specific receptor pathway involved with the catecholamine preconditioning and to test if adenosine plays a role in this cardioprotective effect. Isolated rat hearts, pretreated with small doses of ㄁- or ㄂-adrenergic agonists/antagonists, were subjected to 20 minutes ischemia and 20 minutes reperfusion by Langendorff perfusion method. Cardiac mechanical functions, lactate dehydrogenase and adenosine release from the hearts were measured before and after the drug treatments and ischemia. In another series of experiments, adenosine A₁ or A₂ receptor blockers were treated prior to administration of adrenergic agonists. Pretreatments of a ㄂-agonist, isoproterenol(10^⁣9∼10^⁣7 M) markedly improved the post-ischemic mechanical function and reduced the lactate dehydrogenase release. Similar cardioprotective effect was observed with an ㄁-agonist, phenylephrine pretreatment, but much higher concentration(10^⁣4 M) was needed to achieve the same degree of cardioprotection. The cardioprotective effects of isoproterenol and phenylephrine pretreatments were blocked by a ㄂₁-adrenergic receptor antagonist, atenolol, but not by an ㄁₁-antagonist, prazosin. Adenosine release from the heart was increased by isoproterenol, and the increase was also blocked by atenolol, but not by prazosin. A selective A₁-adenosine receptor antagonist, 1,3-dipropyl-8-cyclopentyl xanthine (DPCPX) blocked the cardioprotection by isoproterenol pretreatment. These results suggest that catecholamine pretreatment protects rat myocardium against ischemia and reperfusion injury by mediation of ㄂₁-adrenergic receptor pathway, and that adenosine is involved in this cardioprotective effect.

키워드

Adenosine Catecholamine preconditioning Ischemia Heart