Antiamnesic effect of metoprine and of selective histamine H₁ receptor agonists in a modified mouse passive avoidance test

详细信息    查看全文

• 作者：Malmberg-Aiello ; Petra ; Ipponi ; Alessandra ; Bartolini ; Alessandro ; Schunack ; Walter
• 关键词：Memory ; Passive avoidance test ; Histamine H₁ receptors ; 2-(3-Trifluoromethylphenyl)histamine ; 2-Thiazolylethylamine ; Pyrilamine ; Histamine-N-methyltransferase inhibitor ; Metoprine
• 刊名：Neuroscience Letters
• 出版年：2000
• 出版时间：July 7, 2000
• 年：2000
• 卷：288
• 期：1
• 页码：1-4
• 全文大小：207 K

文摘

The aim of this study was to elucidate the effect caused by the inhibition of histamine catabolism by means of metoprine and the activation of histamine H₁ receptors by selective agonists on learning and memory processes, using a modified method of the mouse passive avoidance test. The administration of scopolamine 1 mg/kg (i.p.) immediately after the training session caused statistically-significant amnesia during the retention trial performed 24 h later. Piracetam (30 mg/kg (i.p.)), used as a positive control, and administered 20 min before the training session, prevented scopolamine-induced memory impairment. The histamine-N-methyltransferase inhibitor, metoprine, (2 and 5 mg/kg (s.c.)) had effects similar to those of this nootropic drug. The highly-selective H₁ receptor agonist, 2-(3-trifluoromethylphenyl)histamine (FMPH) (2.65 and 6.5 μg/mouse (i.c.v.)) and the less selective agonist, 2-thiazolylethylamine (2-TEA) (0.1 and 0.3 μg/mouse (i.c.v.)) both antagonized the scopolamine-induced amnesia significantly and in a dose-related manner. The selective H₁ receptor antagonist, pyrilamine (20 mg/kg (i.p.)), revealed no effect by itself, but significantly prevented the antiamnesic action both that of the H₁ receptor agonists, and that of endogenous histamine, released by metoprine, thus suggesting a cognitive improvement via the activation of H₁ receptors.