Du Qiu-Xiang, Yue Wei, Wang Ying-Yuan
Department of Forensic Pathology, School of Forensic Medicine, Shanxi Medical University, Taiyuan 030001, China.
Fa Yi Xue Za Zhi. 2011 Jun;27(3):164-8.
To investigate the effect and potential mechanism of intermedin (IMD) in acute cardiac ischemic injury and to provide a new approach for exploring mechanism of sudden cardiac death.
Seventy-two healthy male rats were randomly divided into 3 groups: control, ischemic and the IMD-treated group. The activity of lactate dehydrogenase (LDH), malondialdehyde (MDA) and superoxide dismutase (SOD) in heart blood were tested by enzyme chemistry method. The mRNA changes of calcitonin receptor-like receptor (CRLR) and receptor activity-modifying proteins (RAMPs) in cardiac were measured by real-time PCR analysis. Myocardial cyclic adenosine monophosphate (cAMP) content was determined by enzyme linked immunosorbent assay (ELISA). Apoptosis related factors Bcl-2 and Bax were detected by immunohistochemistry.
Comparing with the control group, LDH and MDA activity of ischemic group in heart blood increased and SOD activity decreased. The concentration of cAMP increased in ventricular muscle, Bcl-2 and Bax proteins expression ratio level decreased. The intravenation of IMD decreased the level of increased activity of LDH and MDA, and lessened the level of decreased activity of SOD. The mRNA expression of CRLR and RAMPs obviously increased in ventricular muscle.
The protective effect of IMD against myocardial ischemic injury could be caused by decreasing the oxidative stress of ischemia and inhibiting the myocardial apoptosis.
探讨中间介质（IMD）在急性心脏缺血性损伤中的作用及潜在机制，为探索心源性猝死机制提供新途径。
将72只健康雄性大鼠随机分为3组：对照组、缺血组和IMD治疗组。采用酶化学法检测心脏血液中乳酸脱氢酶（LDH）、丙二醛（MDA）和超氧化物歧化酶（SOD）的活性。通过实时PCR分析测定心脏中降钙素受体样受体（CRLR）和受体活性修饰蛋白（RAMPs）的mRNA变化。采用酶联免疫吸附测定（ELISA）法测定心肌环磷酸腺苷（cAMP）含量。通过免疫组织化学检测凋亡相关因子Bcl-2和Bax。
与对照组相比，缺血组心脏血液中LDH和MDA活性升高，SOD活性降低。心室肌中cAMP浓度升高，Bcl-2和Bax蛋白表达比例水平降低。静脉注射IMD降低了LDH和MDA活性升高的水平，并减轻了SOD活性降低的水平。心室肌中CRLR和RAMPs的mRNA表达明显增加。
IMD对心肌缺血性损伤的保护作用可能是通过降低缺血的氧化应激和抑制心肌细胞凋亡来实现的。
