Pack R J, Alley M R, Dallimore J A, Lapwood K R, Burgess C, Crane J
Department of Physiology and Anatomy, Massey University, Palmerston North, New Zealand.
Int J Exp Pathol. 1994 Oct;75(5):357-62.
Three groups, each of four sheep, were randomly allocated under blinded conditions to receive the beta-adrenoceptor agonists, salbutamol, fenoterol or isoprenaline, in doses of 0.5, 2, 8, 32 and 128 micrograms/kg intravenously at 15-minute intervals. A separate group of four animals received equal volumes of saline. Heart rate was recorded immediately prior to each drug administration and serum potassium was measured. Three to 4 days later the experiment was repeated during induced systemic hypoxia and the animals then necropsied. All the agonists produced significant increases in heart rate. During hypoxia, lower heart rates were recorded than in the normoxic experiments. Under conditions of hypoxia, all the beta-agonists produced significant hypokalaemia. Sterile saline had no effect on either heart rate or serum potassium levels. At necropsy, myocardial lesions were found in animals receiving all three beta-agonists. Subendocardial haemorrhage was consistently seen in all animals receiving fenoterol. Multifocal myonecrosis of 3-4 days duration was present in the left ventricle of all animals receiving fenoterol, in two receiving isoprenaline and in two receiving salbutamol. The lesions were most severe in the papillary muscle and were visible grossly in one animal given fenoterol and one given isoprenaline. No lesions were found in the control animals.
将三组，每组四只绵羊，在盲法条件下随机分配，以静脉注射的方式每隔15分钟接受剂量为0.5、2、8、32和128微克/千克的β-肾上腺素能激动剂沙丁胺醇、非诺特罗或异丙肾上腺素。另一组四只动物接受等量的生理盐水。在每次给药前立即记录心率并测量血清钾。3至4天后，在诱导全身性缺氧期间重复该实验，然后对动物进行尸检。所有激动剂均使心率显著增加。在缺氧期间，记录到的心率低于常氧实验。在缺氧条件下，所有β-激动剂均导致显著的低钾血症。无菌生理盐水对心率或血清钾水平均无影响。尸检时，在接受所有三种β-激动剂的动物中发现了心肌病变。在所有接受非诺特罗的动物中均持续出现心内膜下出血。在所有接受非诺特罗的动物的左心室中存在持续3 - 4天的多灶性心肌坏死，在两只接受异丙肾上腺素的动物和两只接受沙丁胺醇的动物中也有发现。病变在乳头肌中最为严重，在一只给予非诺特罗的动物和一只给予异丙肾上腺素的动物中肉眼可见。在对照动物中未发现病变。
