Roberts A J, Polis I Y, Gold L H
Department of Neuropharmacology, The Scripps Research Institute, La Jolla, CA 92037, USA.
Eur J Pharmacol. 1997 May 20;326(2-3):119-25. doi: 10.1016/s0014-2999(97)85405-2.
Polydrug abuse, including the abuse of cocaine + heroin combinations (or 'speedballs') is an increasingly significant problem. The use of genetically defined populations of mice has the potential to add considerably to the study of polydrug abuse. Balb/cByJ (Balb/c) mice have been shown to self-administer opiates, but not cocaine, therefore these mice were chosen for the initial characterization of intravenous self-administration of cocaine + heroin combinations. Mice were implanted with chronic indwelling jugular catheters and given the opportunity to self-administer heroin, cocaine or heroin + cocaine combinations. Heroin was self-administered, while, under the same conditions, none of the mice tested acquired cocaine self-administration. However, heroin + cocaine combinations were self-administered in naive mice as well as in mice that had failed to self-administer cocaine alone. The heroin + cocaine combination dose-effect curve resembled the heroin dose-effect curve. It is hypothesized that heroin may interact with effects of cocaine that function to limit self-administration in Balb/c mice, facilitating the acquisition and maintenance of self-administration of cocaine + heroin combinations.
多药滥用，包括可卡因与海洛因联合滥用（即“速球”），是一个日益严重的问题。利用基因定义的小鼠群体，有可能极大地推动多药滥用的研究。已证实Balb/cByJ（Balb/c）小鼠会自我给药阿片类药物，但不会自我给药可卡因，因此选择这些小鼠来初步表征静脉注射可卡因与海洛因联合用药的自我给药情况。给小鼠植入慢性留置颈静脉导管，让它们有机会自我给药海洛因、可卡因或海洛因 + 可卡因组合。小鼠会自我给药海洛因，而在相同条件下，接受测试的小鼠均未形成可卡因自我给药行为。然而，海洛因 + 可卡因组合在未接触过药物的小鼠以及单独未能自我给药可卡因的小鼠中都出现了自我给药现象。海洛因 + 可卡因组合的剂量效应曲线与海洛因剂量效应曲线相似。据推测，海洛因可能与可卡因的某些作用相互影响，这些作用在Balb/c小鼠中限制了自我给药行为，从而促进了可卡因 + 海洛因组合自我给药行为的形成和维持。
