Bhattacharya S K, Upadhyay S N, Jaiswal A K, Bhattacharya S
Indian J Exp Biol. 1989 Mar;27(3):261-4.
Piracetam is the prototype of a new class of psychotropic drugs, the nootropic agents, which are claimed to selectively improve the higher telencephalic integrative activities. The effect of piracetam on rat brain monoamines and prostaglandins (PGs) was assessed so as to garner information on its mode of action. Two doses of the drug were used, a lower dose (20 mg/kg ip) and a higher dose (100 mg/kg, ip), the latter being known to exert a facilitatory effect on learning and memory. Piracetam produced a dose-related effect on rat brain serotonin (5HT) and noradrenaline (NA), with the lower dose inducing a decrease in 5HT levels and an increase in NA concentrations. The higher dose of piracetam produced the opposite effect. Dopamine (DA) levels were not significantly affected. The lower dose of the drug attenuated 5HT turnover and augmented that of NA, whereas the higher dose of piracetam produced the reverse effects, in clorgyline treated rats. The lower dose of piracetam produced a slight and statistically insignificant increase in rat brain PGE2 and PGF2 alpha. However, the higher dose of the drug produced marked increase in the levels of both the PGs. The observed biochemical effects may provide a basis for the nootropic effect of piracetam. However, they may also be due to the GA-BA-mimetic action of the drug, particularly those observed with the lower dose of piracetam.
吡拉西坦是一类新型精神药物促智药的原型，据称这类药物能选择性地改善大脑高级整合活动。评估了吡拉西坦对大鼠脑单胺类物质和前列腺素（PGs）的影响，以获取其作用方式的信息。使用了两种剂量的药物，较低剂量（20毫克/千克，腹腔注射）和较高剂量（100毫克/千克，腹腔注射），后者已知对学习和记忆有促进作用。吡拉西坦对大鼠脑血清素（5HT）和去甲肾上腺素（NA）产生剂量相关效应，较低剂量导致5HT水平降低和NA浓度升高。较高剂量的吡拉西坦产生相反的效应。多巴胺（DA）水平未受到显著影响。在氯吉兰处理的大鼠中，较低剂量的药物减弱了5HT的周转并增强了NA的周转，而较高剂量的吡拉西坦产生相反的效应。较低剂量的吡拉西坦使大鼠脑前列腺素E2（PGE2）和前列腺素F2α（PGF2α）略有增加，但在统计学上无显著意义。然而，较高剂量的药物使两种PGs的水平显著增加。观察到的生化效应可能为吡拉西坦的促智作用提供了基础。然而，它们也可能归因于该药物的γ-氨基丁酸模拟作用，特别是在较低剂量的吡拉西坦时观察到的那些作用。
