白细胞介素-2对离体大鼠心脏的作用及其机理

本实验研究免疫调节因子IL-2对心脏的生物学作用及其机制.实验结果显示,hrIL-2增加离体心脏的室性早搏个数,增加心率,影响左室发展压、左室舒张末压和冠脉流量;热失活的hrIL-2对心脏无作用;Ryanodine预处理不改变hrIL-2的致心律失常作用和增加心率的作用,但取消了hrIL-2增加左室发展压、左室舒张末压和冠脉流量的作用;Nifedipine和低钙均取消了hrIL-2的致心律失常作用,部分取消了hrIL-2增加心率、左室发展压、左室舒张末压和冠脉流量的作用.结果提示,IL-2可导致离体心脏心律失常和正性变时变力作用,其心脏作用与其正常的空间结构有关,作用机制涉及跨膜内流钙和胞浆内钙.

EFFECTS OF INTERLEUKIN- 2 ON THE ISOLATED RAT HEART AND THE MECHANISM

The purpose of the present study was to explore the biological effects and mechanism of interleukin - 2 (IL -2) on the isolated rat heart. The results showed that hrIL - 2 increased the number of premature ventricular contraction, heart rate, left ventricular developed pressure, left ventricular end - diastolic pressure and coronary flow in the isolated perfused rat heart. Heat inactivated hrIL-2 had no effect on the heart. Pretreatment with ryanodine canceled the positive effects of hrIL - 2 on left ventricular developed pressure, left ventricular end - diastolic pras- sure and coronary flow but had no effects on arrhythmo-genesis and tachycardia by hrIL - 2. Pretreatment with nifedipine or low extracellular calcium abolished the ar-rhythmogenic effect of hrIL - 2 and attenuated partially the augment of heart rate, left ventricular developed pressure, left ventricular end - diastolic pressure and coronary flow. It suggests that the cardiac activity of hrIL - 2 depended on the integrity of its spatial structure and trans-membrane influx Ca 2 and intracellularly stored Ca2 were involved in the cardiac activity of hrIL-2.