Guzman Daniel, Ettenberg Aaron
Behavioral Pharmacology Laboratory, Department of Psychology (9660), University of California, Santa Barbara, CA 93106, USA.
Pharmacol Biochem Behav. 2004 Oct;79(2):317-24. doi: 10.1016/j.pbb.2004.08.009.
It has been presumed that the combination of cocaine (COC)+heroin (HER) is more reinforcing than either of the two drugs alone, thus leading to their coadministration ("speedballing"). An alternative hypothesis is that HER serves to attenuate the undesired negative effects of COC. To test this notion, male Sprague-Dawley rats (n=31) were trained to run a straight alley for a daily intravenous (IV) injection of COC (1.0 mg/kg/injection) for 14 trials. Studies in our laboratory have shown that such animals begin to exhibit approach-avoidance behaviors ("retreats") stemming from concurrent positive and negative associations with the goal box (which, in turn, are the result of COC's immediate rewarding and subsequent dysphoric actions). Thus, retreats can be used as a reliable index of COC's anxiogenic side effects. Following 14 COC-reinforced trials, animals were split into three groups matched on mean retreat frequency. One group (n=11) received IV COC (1.0 mg/kg/injection) for seven additional trials; the remaining two groups (n=10 each) received an IV injection of COC mixed in a single solution with either a low dose (0.025 mg/kg/injection) or a high dose (0.1 mg/kg/injection) of HER. It was hypothesized that adding HER would attenuate the negative consequences of COC administration and thereby produce a reliable decrease in the occurrence of retreats. The resulting data were consistent with this hypothesis, suggesting that "speedballing" in human addicts may be motivated by a desire to reduce the negative impact of COC use.
据推测，可卡因（COC）和海洛因（HER）的组合比单独使用这两种药物中的任何一种更具强化作用，因此导致它们同时使用（“速球”）。另一种假设是，海洛因可减轻可卡因的不良负面影响。为了验证这一观点，对31只雄性斯普拉格-道利大鼠进行训练，让它们在直道上奔跑，以便每天静脉注射（IV）可卡因（1.0毫克/千克/次），共进行14次试验。我们实验室的研究表明，这些动物开始表现出接近-回避行为（“退缩”），这源于与目标箱同时存在的正负关联（反过来，这是可卡因即时奖赏和随后烦躁不安作用的结果）。因此，退缩可作为可卡因致焦虑副作用的可靠指标。在进行14次可卡因强化试验后，将动物分为三组，根据平均退缩频率进行匹配。一组（n = 11）再接受7次静脉注射可卡因（1.0毫克/千克/次）；其余两组（每组n = 10）接受静脉注射与低剂量（0.025毫克/千克/次）或高剂量（0.1毫克/千克/次）海洛因混合在单一溶液中的可卡因。假设添加海洛因会减轻可卡因给药的负面后果，从而使退缩发生率可靠降低。所得数据与该假设一致，表明人类成瘾者的“速球”行为可能是出于减少使用可卡因负面影响的愿望。
