Häggendal J, Johansson G, Jönsson L, Thorén-Tolling K
Acta Pharmacol Toxicol (Copenh). 1984 Sep;55(3):161-7. doi: 10.1111/j.1600-0773.1984.tb02031.x.
The degree of myocardial cell necroses after stress was investigated in 6 pigs, weighing 70 to 90 kg. The stress was induced by a myorelaxant, succinylcholine, for about 12 min. The alpha-adrenoceptor blocking agent phenoxybenzamine (PBZ) was given orally 3 times a day in a total dose of 50 to 60 mg per day for 6 to 7 days before the stress. The plasma levels of noradrenaline and adrenaline were assayed in blood samples drawn before, during, and immediately after the period of stress. Heart cell necroses were found in all the cases. The activity of the sympathetic-adrenomedullary system, indicated by the plasma levels of catecholamines, was intense during the stress. When the present results were compared with those of earlier studies the degree of heart cell necroses was significantly smaller after PBZ in control pigs but significantly higher than after the beta-adrenoceptor blocking agent propranolol given for about a week. PBZ exerts a number of different actions, as briefly discussed, some of them appearing to be harmful for the heart during stress while others appear to be protective for the heart.
对6头体重70至90公斤的猪进行了应激后心肌细胞坏死程度的研究。应激由肌松剂琥珀酰胆碱诱发，持续约12分钟。在应激前6至7天，每天口服α-肾上腺素能受体阻滞剂酚苄明（PBZ）3次，总剂量为每天50至60毫克。在应激期之前、期间和之后立即采集的血样中检测去甲肾上腺素和肾上腺素的血浆水平。在所有病例中均发现了心肌细胞坏死。以儿茶酚胺血浆水平表示的交感-肾上腺髓质系统的活性在应激期间增强。当将本研究结果与早期研究结果进行比较时，对照猪在给予PBZ后心肌细胞坏死程度明显较小，但明显高于给予β-肾上腺素能受体阻滞剂普萘洛尔约一周后的坏死程度。如简要讨论的那样，PBZ具有多种不同作用，其中一些作用在应激期间似乎对心脏有害，而另一些作用似乎对心脏具有保护作用。
