Calcium antagonists isradipine and nimodipine suppress cocaine and morphine intravenous self-administration in drug-naive mice. |
| |
Authors: | A Kuzmin E Zvartau G L Gessa M C Martellotta W Fratta |
| |
Institution: | Department of Pharmacology, Pavlov Medical Institute, St. Petersburg, Russia. |
| |
Abstract: | The effect of isradipine and nimodipine, two dihydropyridine calcium antagonists, on intravenous self-administration of cocaine and morphine in naive mice has been investigated. When morphine or cocaine injections were made contingent upon nose-poke response by naive mice, they increased their rate of nose-poking with respect to animals receiving contingent saline injections or yoked control animals, receiving noncontingent cocaine or morphine injections. Pretreatment of mice with isradipine (1.0-3.0 mg/kg, SC) or nimodipine (5-20 mg/kg, SC) inhibited in a dose-related manner self-administration both of cocaine and morphine contingent upon a nose-poke response. The ED50 of isradipine against cocaine and morphine self-administration was 1.7 and 2.1 mg/kg, respectively. The relative values for nimodipine were 14.5 and 11.4 mg/kg, respectively. These data suggest that nimodipine and, especially, isradipine suppress the reinforcing properties of morphine and cocaine and may be an effective pharmacotherapy for treatment of cocaine and heroin abuse. |
| |
Keywords: | |
|
|