Todorov S, Zamfirova R, Petkov V D
Institute of Physiology, Bulgarian Academy of Sciences.
Acta Physiol Pharmacol Bulg. 1990;16(1):38-45.
The effects of compounds from the group of nootropic agents on the peripheral adrenergic neurotransmission in animals of different ages were studied in in vitro experiments. The experiments were performed on smooth muscle preparations isolated from young sexually mature (4-5-month-old) and old (22 month-old) rats treated twice daily for 7 days with 50 mg/kg of the nootropic agents piracetam, its structural analogues p-H and p-Cl, aniracetam and Ginseng extract. The animals were decapitated on the 7th day, the changes in the contractile responses of the smooth muscles to noradrenaline (NA) or electrical stimulation (ES) were studied in isolated preparations from vas deferens, aorta and anococcygeal muscle. The results show that the compounds studied can modulate the contractile effects of NA and ES, their action being most often potentiating and more pronounced in the smooth muscles manifesting weaker responses. In some cases the reactivity of the smooth muscle preparations to the stimuli applied was reduced after the nootropic agents. These effects can be partly explained with changes in the sensitivity of the pre- and postsynaptic alpha-adrenergic receptors. The possible variabilities in the influence on the two receptor populations in the different smooth muscles could explain the differences in the observed modulatory effects of the nootropic agents. The data obtained show that in prolonged therapeutic application of nootropic agents it is necessary to bear also in mind their possible influence on the peripheral neurotransmitter systems.
在体外实验中研究了促智药组化合物对不同年龄动物外周肾上腺素能神经传递的影响。实验采用从幼年性成熟（4 - 5月龄）和老年（22月龄）大鼠分离的平滑肌制剂进行，这些大鼠每天用50mg/kg的促智药吡拉西坦、其结构类似物对羟基吡拉西坦和对氯吡拉西坦、阿尼西坦以及人参提取物处理两次，持续7天。在第7天处死动物，研究输精管、主动脉和肛门尾骨肌分离制剂中平滑肌对去甲肾上腺素（NA）或电刺激（ES）的收缩反应变化。结果表明，所研究的化合物可调节NA和ES的收缩作用，其作用通常是增强性的，并且在反应较弱的平滑肌中更明显。在某些情况下，促智药处理后平滑肌制剂对施加刺激的反应性降低。这些效应部分可以用突触前和突触后α - 肾上腺素能受体敏感性的变化来解释。对不同平滑肌中两种受体群体影响的可能差异可以解释促智药观察到的调节作用的差异。获得的数据表明，在促智药的长期治疗应用中，还必须考虑它们对外周神经递质系统的可能影响。
