Häggendal J, Johansson G, Jönsson L, Thorén-Tolling K
Acta Pharmacol Toxicol (Copenh). 1982 Jan;50(1):58-66. doi: 10.1111/j.1600-0773.1982.tb00940.x.
The degree of myocardial cell necroses in pigs exposed to stress induced by a myorelaxant (succinylcholine) for about 12 min. was investigated. The Beta-adrenoceptor block propranolol was given in varying doses prior to the induced stress. The degree of necroses in these pigs was evaluated according to a point scale, ranging from 0 to 6 points, and compared with the changes found in untreated controls following stress. The blood levels of noradrenaline and adrenaline were assayed before, during an immediately after the period of stress. No protective effect of propranolol on the cardiac lesions was found when the drug was administered intravenously in a single dose of either 1 mg or 3 mg per kg. During the period of stress the blood levels of noradrenaline were high, indicating a high degree of activity in the sympatho-adrenal system. Propranolol in a single dose of 10 mg per kg intravenously reduced the number and size of heart lesions, while the blood levels of the catecholamines were lower under stress than after administration of 1 and 3 mg propranolol. After oral treatment with propranolol, 120 mg three times a day for 6 or 7 days, an almost complete absence of heart cell necrosis after the stress was obtained. The activity of the sympatho-adrenal system was elevated, as reflected by the high blood levels of catecholamines. The results indicate that stress-induced heart cell necrosis is mediated via the activity of the sympatho-adrenal system. The difference between a single and repeated doses of propranolol in protecting the heart suggests a complex of the adrenergic Beta-receptor blocker.
研究了猪在接受肌松剂（琥珀酰胆碱）诱导的约12分钟应激后心肌细胞坏死的程度。在诱导应激前给予不同剂量的β-肾上腺素能受体阻滞剂普萘洛尔。根据0至6分的评分标准评估这些猪的坏死程度，并与应激后未治疗的对照组中发现的变化进行比较。在应激期之前、期间和刚结束后测定去甲肾上腺素和肾上腺素的血药浓度。当静脉注射每千克1毫克或3毫克的单剂量普萘洛尔时，未发现其对心脏病变有保护作用。在应激期间，去甲肾上腺素的血药浓度很高，表明交感-肾上腺系统的活性很高。静脉注射每千克10毫克的单剂量普萘洛尔可减少心脏病变的数量和大小，而应激期间儿茶酚胺的血药浓度低于给予1毫克和3毫克普萘洛尔后。口服普萘洛尔，每天三次，每次120毫克，持续6或7天，应激后几乎完全没有心肌细胞坏死。交感-肾上腺系统的活性升高，这通过儿茶酚胺的高血药浓度反映出来。结果表明，应激诱导的心肌细胞坏死是通过交感-肾上腺系统的活性介导的。普萘洛尔单次和重复给药在保护心脏方面的差异表明肾上腺素能β受体阻滞剂存在复杂性。
