Kvaltínová Z, Lukovic L, Stolc S
Institute of Experimental Pharmacology, Slovak Academy of Sciences, Bratislava.
Neuropharmacology. 1993 Aug;32(8):785-91. doi: 10.1016/0028-3908(93)90187-8.
The effect of incomplete 4 hr ischemia and subsequent 1 hr reperfusion of the rat brain on the density and affinity of alpha-adrenergic binding sites was investigated. To assess the involvement of oxygen-derived free radicals in the development of ischemic injury, we tested the effect of stobadine and vitamin E on putative changes of the binding parameters of alpha-adrenergic binding sites in ischemic and reperfused rat brains. Compared to the group of sham operated animals decreased density and increased affinity of [3H]dihydroergocryptine binding sites was found in cerebrocortical membranes of rats subjected to 4 hr incomplete ischemia and 1 hr reperfusion. The reduction of Bmax and Kd induced by ischemia and reperfusion of the brain was prevented by stobadine and vitamin E administration. Neither incomplete ischemia nor incomplete ischemia and subsequent reperfusion of the rat brain exerted significant effect on [3H]rauwolscine binding to alpha 2-adrenergic binding sites. Our results suggest that brain ischemia and reperfusion may affect the density and affinity of alpha 1- rather than of alpha 2-adrenergic binding sites. The beneficial effect of stobadine and vitamin E indicates that increased generation of oxygen free radicals might play a role in the development of these changes.
研究了大鼠脑不完全缺血4小时及随后再灌注1小时对α-肾上腺素能结合位点密度和亲和力的影响。为评估氧衍生自由基在缺血性损伤发展中的作用，我们测试了司巴丁和维生素E对缺血再灌注大鼠脑α-肾上腺素能结合位点结合参数假定变化的影响。与假手术动物组相比，在经历4小时不完全缺血和1小时再灌注的大鼠脑皮质膜中，发现[3H]二氢麦角隐亭结合位点的密度降低而亲和力增加。司巴丁和维生素E给药可防止脑缺血和再灌注诱导的Bmax和Kd降低。大鼠脑的不完全缺血或不完全缺血及随后的再灌注对[3H]萝芙木碱与α2-肾上腺素能结合位点的结合均无显著影响。我们的结果表明，脑缺血和再灌注可能影响α1-而非α2-肾上腺素能结合位点的密度和亲和力。司巴丁和维生素E的有益作用表明，氧自由基生成增加可能在这些变化的发展中起作用。
