Grong K, Jodalen H, Stangeland L, Vik-Mo H, Lekven J
Cardiovasc Res. 1986 Apr;20(4):248-55. doi: 10.1093/cvr/20.4.248.
The effects of non-selective beta adrenergic blockade on intracellular lipid accumulation in hearts with acute ischaemia were studied by electron microscopy of myocardial biopsy specimens using quantitative stereological techniques. Pentobarbital anaesthetised cats with coronary ligation were divided into eight controls and eight cats treated with timolol intravenously just before ligation. Biopsy specimens were collected from ischaemic, borderline, and normally perfused myocardium, defined by an in vivo injection of fluorescein and verified by regional myocardial blood flow measurements with 15 microns radiolabelled microspheres. During a 3 h occlusion period timolol treated cats had a lower heart rate, left ventricular dP/dt, and plasma free fatty acid concentration. In control cats the cytosolic volume fraction of lipids was 0.71 X 10(-3) in non-ischaemic myocardium, 2.63 X 10(-3) in central ischaemic tissue, and 6.53 X 10(-3) in borderline tissue. Timolol reduced the appreciable lipid accumulation in borderline tissue by 24% (to 4.97 X 10(-3)) compared with controls, whereas accumulation in central ischaemic tissue was not affected. Thus timolol diminished lipid accumulation in borderline myocardial tissue. The mechanism is most likely related to reduced ischaemic intensity and better preserved metabolic function.
采用定量体视学技术，通过对心肌活检标本进行电子显微镜检查，研究了非选择性β肾上腺素能阻滞剂对急性缺血心脏细胞内脂质蓄积的影响。将戊巴比妥麻醉、冠状动脉结扎的猫分为八只对照组和八只在结扎前静脉注射噻吗洛尔的猫。通过体内注射荧光素确定，并经用15微米放射性微球测量局部心肌血流证实，从缺血、边缘和正常灌注的心肌采集活检标本。在3小时的闭塞期内，噻吗洛尔治疗的猫心率、左心室dp/dt和血浆游离脂肪酸浓度较低。在对照猫中，非缺血心肌中脂质的胞浆体积分数为0.71×10⁻³，中央缺血组织中为2.63×10⁻³，边缘组织中为6.53×10⁻³。与对照组相比，噻吗洛尔使边缘组织中明显的脂质蓄积减少了24%（降至4.97×10⁻³），而中央缺血组织中的蓄积未受影响。因此，噻吗洛尔减少了边缘心肌组织中的脂质蓄积。其机制很可能与缺血强度降低和代谢功能更好的保存有关。
