HYPOTHERMIC EFFECT OF HARMALA ALKALOID IN RATS - INVOLVEMENT OF SEROTONERGIC MECHANISM
HYPOTHERMIC EFFECT OF HARMALA ALKALOID IN RATS - INVOLVEMENT OF SEROTONERGIC MECHANISM
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DOI：
10.1016/0091-3057(95)00131-f
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发表时间：
1995-10-01
影响因子：
3.6
通讯作者：
WATANABE, H
中科院分区：
文献类型：
--
作者：
ABDELFATTAH, AFM;MATSUMOTO, K;WATANABE, H
采用大鼠体温实验，研究了埃及产槟榔籽中提取的总生物碱对大鼠体温的影响。腹腔注射槟榔提取物可产生明显的剂量依赖性低体温。同样，咸草生物碱的主要成分咸草碱和咸草碱也能降低体温。5-HT合成抑制剂对氯苯丙氨酸（100 mg/kg/d，连用3天）预处理后，总生物碱和毒蜂碱的降体温作用显著减弱，有阻断毒蜂碱降体温作用的趋势。5-羟色胺拮抗剂甲塞吉胺（2mg /kg）可显著减弱哈玛拉生物碱所致的低温。5-HT1A受体和β -肾上腺素受体拮抗剂品多洛尔（0.05-2 mg/kg）部分阻断了哈玛拉生物碱的降体温作用，呈剂量依赖性，而β -肾上腺素受体拮抗剂心得安（10 mg/kg）未能改变这种作用，提示β -肾上腺素受体与生物碱引起的体温降低无关。多巴胺受体拮抗剂氟哌啶醇（5 mg/kg， SC和2 mg/kg，实验前24和2 h）预处理显著减弱了哈玛拉生物碱的降体温作用。氟哌啶醇预处理大鼠，甲基塞吉特（2 mg/kg， IP）和品多洛尔（0.05和2 mg/kg）完全减弱了生物碱的降温作用。这些数据表明，苦参生物碱主要通过内源性5-HT刺激5-HT1A受体产生降体温作用。
The effect of total alkaloid extracted from Peganum harmala seeds collected in Egypt on body temperature was studied in rats. Intraperitoneal administration of the Peganum harmala extract produced significant and dose-dependent hypothermia. Similarly, harmine and harmaline, major constituents of the harmala alkaloid, lowered the body temperature. Pretreatment with p-chlorophenylalanine (100 mg/kg/day for 3 days), a 5-HT synthesis inhibitor, significantly attenuated the hypothermic effect of the total alkaloid and harmine, while it tended to block the hypothermic action of harmaline. Methysergide (2 mg/kg), a 5-HT antagonist, significantly attenuated the hypothermia induced by harmala alkaloids. Pindolol (0.05-2 mg/kg), a 5-HT1A receptor and beta-adrenoceptor antagonist, partly blocked the hypothermic effect of the harmala alkaloids in a dose-dependent manner, whereas propranolol (10 mg/kg), a beta-adrenoceptor antagonist, failed to alter it, suggesting that beta-adrenoceptor is not involved in the hypothermia caused by the alkaloids. Pretreatment with a dopamine receptor antagonist haloperidol (5 mg/kg, SC and 2 mg/kg, IP 24 and 2 h before the experiment, respectively) significantly attenuated the hypothermic effect of harmala alkaloids. Moreover, in haloperidol pretreated rats, methysergide (2 mg/kg, IP) and pindolol (0.05 and 2 mg/kg) completely attenuated the hypothermic effect of the alkaloids. These data suggest that harmala alkaloids produce hypothermic effect mainly through endogenous 5-HT stimulation of 5-HT1A receptor.