Methamphetamine

甲基苯丙胺
Mechanism of action:
Methamphetamine 是一種中樞神經 刺激劑(central nervous system stimulant),屬於苯乙胺類(phenethylamine)衍生物,結構上與安非他命(amphetamine)相近,但因脂溶性較高,更容易穿越血腦障壁。Methamphetamine 會透過多巴胺轉運蛋白(dopamine transporter)、正腎上腺素轉運蛋白(norepinephrine transporter)、血清素轉運蛋白(serotonin transporter)進入突觸前神經元。Methamphetamine 會抑制 VMAT2(vesicular monoamine transporter 2)轉運蛋白,使多巴胺等單胺類物質無法正常儲存在突觸囊泡中,導致大量神經傳導物質被滯留於細胞質內。細胞質內累積的多巴胺、正腎上腺素、血清素會分別被它們各自的轉運蛋白反向釋放至突觸間隙,造成突觸間神經傳導物質濃度急劇上升,強化對神經元的刺激。
Reference(s):
1. Schepers RJ et al. (2003). Methamphetamine and amphetamine pharmacokinetics in oral fluid and plasma after controlled oral methamphetamine administration to human volunteers. Clin Chem.
2. McGregor C et al. (2005). The nature, time course and severity of methamphetamine withdrawal. Addiction.
3. Bennett BA et al. (1998). Methamphetamine-induced alterations in dopamine transporter function. Brain Res.
