Methylamine and benzylamine induced hypophagia in mice: Modulation by semicarbazide-sensitive benzylamine oxidase inhibitors and aODN towards Kv1.1 channels
作者:R Pirisino、C Ghelardini、G Banchelli、N Galeotti、L Raimondi
DOI:10.1038/sj.bjp.0704316
日期:2001.10
In starved mice, the anorectic activity of methylamine (MET) and benzylamine (BZ), both substrates of semicarbazide‐sensitive benzylamine oxidases (Bz‐SSAO), was compared with that of the potassium channel blocking agents charybdotoxin (ChTX), tetraethylammonium (TEA), gliquidone (GLI), ammonium chloride (NH4+) and of the anoressants amphetamine (AMPH) and nicotine (NIC). After i.c.v. administration, an approximate ranking order of potency was: ChTXAMPH>NIC=TEAGLIMET>BZ>NH4+.
Clorgyline (2.5 mg kg−1 i.p.) or deprenyl (10 mg kg−1 i.p.) potentiated the anorectic effect of i.c.v.‐administered BZ, NIC and AMPH. The effect of TEA was increased only by deprenyl, while MET, NH4+, ChTX and GLI were not affected by either of the inhibitors.
The Bz‐SSAO inhibitors α‐aminoguanidine (50 mg kg−1 i.p.), B24 (100 mg kg−1 i.p.) and MDL 72274 (2.5 mg kg−1 i.p.) potentiated the effect of i.p., but not of i.c.v.‐administered MET.
Antisense oligodeoxyribonucleotides (aODN) to Kv1.1 potassium channels abolished the effect of BZ and TEA, but was ineffective in reducing the activity of MET and other compounds.
These results suggest that MET is endowed with peculiar hypophagic effects at dosage levels that are not able to affect gross behaviour in mice. The effect of MET, differently from BZ, seems unrelated to an increase in the central release of monoaminergic mediators, as well as to a Kv1.1 blocking activity. Through a reduction of the endogenous breakdown of MET, Bz‐SSAO inhibitors enhance the central pharmacological activity of this amine.
British Journal of Pharmacology (2001) 134, 880–886; doi:10.1038/sj.bjp.0704316
在慢性饥饿的小鼠中,甲胺(MET)和苯乙酰胺(BZ)的厌食作用(两者均为半甲酰肼敏感的苯乙酰胺氧化酶(Bz-SSAO)的底物)与钾通道阻滞剂氯毒素(ChTX)、四乙铵(TEA)、gliquidone(GLI)、氯化铵(NH4+)以及厌食剂安非他明(AMPH)和尼古丁(NIC)的厌食作用进行了比较。在脑室内给药后,效力的大致排序为:ChTX > AMPH > NIC = TEA = GLI = MET > BZ > NH4+。Clorgyline(2.5 mg/kg,ip)或Deprenyl(10 mg/kg,ip)增强了脑室内给药的BZ、NIC和AMPH的厌食作用。Deprenyl仅增强TEA的作用,而MET、NH4+、ChTX和GLI不受这两种抑制剂的影响。Bz-SSAO抑制剂α-氨基胍(50 mg/kg,ip)、B24(100 mg/kg,ip)和MDL 72274(2.5 mg/kg,ip)增强了ip条件下但并非icv条件下给药的MET的作用。针对Kv1.1钾通道的反义寡脱氧核苷酸(aODN)消除了BZ和TEA的作用,但对MET和其他化合物的作用无效。这些结果表明,MET在不影响小鼠一般行为的剂量水平下具有独特的抑制摄食作用。与BZ不同,MET的作用似乎与中枢单胺递质的释放增加无关,也与Kv1.1阻断活性无关。通过减少MET的内源性分解,Bz-SSAO抑制剂增强了该胺类的中枢药理活性。
期刊引用:*British Journal of Pharmacology* (2001) **134**, 880–886; doi: [10.1038/sj.bjp.0704316](10.1038/sj.bjp.0704316)