Glowa J R, Sobel E, Malaspina S, Dews P B
Psychopharmacology (Berl). 1985;87(4):421-4. doi: 10.1007/BF00432506.
The effects of caffeine (1-100 mg/kg, IP), (-)N-((R)-1-methyl-2-phenylethyl)-adenosine (PIA) (0.01-1 mg/kg, IP), and of the two drugs in combination were studied in mice responding under a mult FR30 FI600 s schedule of food presentation. The lowest dose of caffeine, 1 mg/kg, had no effect on responding under either component of the mult schedule. Intermediate doses of caffeine (3 and 10 mg/kg) slightly increased responding under the FI component, while higher doses decreased responding. Caffeine only decreased responding, at doses above 30 mg/kg, under the FR component. PIA decreased responding under both components of the mult schedule in a dose-dependent, and similar, manner. In most cases, the rate-increasing effect of caffeine on FI responding was diminished when combined with a rate-decreasing dose of PIA. However, when 0.01 mg/kg PIA, a dose that had no effect alone, was combined with 3 mg/kg caffeine, the increase in rate exceeded that of caffeine alone. Rate-decreasing effects of PIA were antagonized by caffeine; with larger doses of PIA, larger doses of caffeine were required for antagonism. Thus, while the rate-increasing effects of caffeine can be either enhanced or diminished, when combined with different doses of PIA, the rate-decreasing effects of PIA are clearly antagonized by caffeine in a dose-dependent manner.
在按多 FR30 FI600 秒食物呈现时间表做出反应的小鼠中，研究了咖啡因（1 - 100 毫克/千克，腹腔注射）、(-)N-((R)-1-甲基-2-苯乙基)-腺苷（PIA）（0.01 - 1 毫克/千克，腹腔注射）以及这两种药物联合使用的效果。咖啡因的最低剂量 1 毫克/千克，对多时间表任何一个组成部分下的反应均无影响。咖啡因的中等剂量（3 和 10 毫克/千克）在 FI 组成部分下略微增加反应，而较高剂量则降低反应。仅在高于 30 毫克/千克的剂量下，咖啡因在 FR 组成部分下才降低反应。PIA 以剂量依赖性且相似的方式降低多时间表两个组成部分下的反应。在大多数情况下，当与降低速率剂量的 PIA 联合使用时，咖啡因对 FI 反应的速率增加作用减弱。然而，当 0.01 毫克/千克的 PIA（单独使用无作用的剂量）与 3 毫克/千克的咖啡因联合使用时，速率增加超过了单独使用咖啡因时的情况。PIA 的降低速率作用被咖啡因拮抗；PIA 剂量越大，拮抗所需的咖啡因剂量就越大。因此，虽然咖啡因的速率增加作用在与不同剂量的 PIA 联合使用时可增强或减弱，但 PIA 的降低速率作用显然被咖啡因以剂量依赖性方式拮抗。
