摘要
本实验在培养的Ｗｉｓｔａｒ大鼠乳鼠心肌细胞上观察了Ｔ—２毒素对膜电位活动的影响及硒的保护作用。结果表明，Ｔ—２毒素（０．１，０．５，５０ｍｇ／Ｌ）使心肌细胞动作电位幅值（ＡＰＡ）、超射（ＯＳ）、阈电位（ＴＰ）、最大舒张电位（ＭＤＰ）及最大除极速率（Ｖ＿（ｍａｘ））显著降低；使复极化时程（ＡＰＤ＿（１０）、ＡＰＤ＿（５０）、ＡＰＤ＿（９０））延长；动作电位发放频率（ＡＰＦ）受到明显抑制。提示Ｔ—２毒素能抑制Ｃａ￣（２＋）、Ｋ￣＋的跨膜转运。０．５ｍｇ／Ｌ硒能使Ｔ—２毒素（１ｍｇ／Ｌ）致心肌细胞动作电位改变的作用明显减小，显示硒具有稳定膜结构与功能的作用。
In the present study,the effect
of T-2 toxin on action potentials of cultured myocardiocytesand the
protective effects of selenium were investigated.Ventricular myocytes
from neonatalWistar rats were cultured, and the transmembrane action
potentials were recorded with glassmicroelectrodes before and after
addtion of T-2 toxin at different concentrations.The resultsshowed
that T-2 toxin at 0.1,1.0 and 5.0 mg/L decreased the action potential
parameters in-cluding action potential
amplitude(APA),overshoot(OS),threshold potential(TP),
maximumdiastolic potential(MDP) and maximum rate of
depolarization(V_(max), and prolonged the actionpotential duration of
10%, 50% and 90% repolarization(APD_(10), APD_(50) and APD_(90)).Some
ofthe parameters changed in a dose-dependent manner. The results
suggest that T-2 toxin may in-terfere with the transmembrane
transport of Ca￣(2+) and k￣+. The cultured myocardiocytespretreated
with 0.5mg / L of selenium for 16 hours presented only slight changes
in action poten-tials induced by T-2 toxin at 1mg / L,suggesting
that selenium may protect the myocardial cellsfrom toxic damages of
T-2 toxin.
出处
《中国应用生理学杂志》
CAS
CSCD
1995年第3期229-232,共4页
Chinese Journal of Applied Physiology
