Physiological effects of magnesium in the guinea pig hearts

기니픽 심장에서 magnesium의 생리학적 영향

  • Chang, Sung-eun (Bio-Safety Research Institute, Chonbuk National University) ;
  • Kim, Shang-jin (Bio-Safety Research Institute, Chonbuk National University) ;
  • Kang, Hyung-sub (Bio-Safety Research Institute, Chonbuk National University) ;
  • Kim, Jin-shang (Bio-Safety Research Institute, Chonbuk National University)
  • 장성은 (전북대학교 생체안전성연구소) ;
  • 김상진 (전북대학교 생체안전성연구소) ;
  • 강형섭 (전북대학교 생체안전성연구소) ;
  • 김진상 (전북대학교 생체안전성연구소)
  • Accepted : 2001.07.11
  • Published : 2001.09.25

Abstract

In this work we have investigated the physiological effects of $MgCl_2$ in isolated atrium, papillary muscle, perfused heart and anesthesized guinea pig, The addition or infusion of $MgCl_2$ (0~20 mM or mg/kg) to perfused hearts and to anesthesized guinea pigs induced a marked and dose-dependent negative chronotropic effect. The sinoatrial node automaticity could also be reduced by $MgCl_2$. The addition of $MgCl_2$to isolated atria and to papillary muscles induced a marked and dose-dependent negative inotropic effect. The threshold voltage could be increased by $MgCl_2$in papillary muscle. Increasing $MgCl_2$ shortened the action potential duration (APD) in dose-dependent manner at 30% ($APD_{30}$) and 90% repolarization ($APD_{90}$) measured with conventional microelectrode technique in papillary muscle. In anesthesized guinea pig, the magnesium infusion resulted in a dose-dependent drop in blood pressure. These results suggested that magnesium is closely associated with cardiac physiological condition and exerts antiarrhythmic activities.