Action potential and L-type calcium channel currents in myocardial cells of rat models of heroin addiction / 中国组织工程研究

ABSTRACT

BACKGROUND:Calcium channel abnormalities can damage myocardium. Heroin can directly affect calcium ion channel, and alter myocardial structure. OBJECTIVE:To study the changes of heroin-induced myocardial ultrastructure, L-type calcium channel current and action potential of myocardial cel s after rat cardiac arrhythmia. METHODS:Sprague-Dawley rats were randomly divided into control group and model group. In the model group, rats were administered heroin at initial dose of 5 mg/kg?d. The daily dose escalation method was used (increasing dose2.5 mg/kg?d) to replicate rat models of heroin addiction. At 20 days, models of heroin addiction were successful y established. At 30 days after increasing the dose, rat models of heroin addiction-induced arrhythmias were further established. RESULTS AND CONCLUSION:Compared with the control group, the electron microscopy demonstrated that myocardial structure changes mainly presented nuclear membrane shrinkage, nuclear condensation, nuclei became smal , chromatin assembled into blocks, mitochondria disordered and disappeared, sarcomeres disordered, focal fracture, and unclear myofilament in rat models of heroin addiction. Electric current-voltage curve of myocardial cel L-type calcium channel current showed the increasing trends. The 90%repolarization action potential was significantly shortened. These data indicated that heroin can directly lead to the pathological change of myocardial structure. Calcium channel current change is one of the main reasons for myocardial injury.