Persistence of "relapse-tendencies" of rats previously made physically dependent on morphine.

摘要: 1. Measurements of 24 hr tap water consumption, body weight, “wet dog” shake frequency and free choice drinking (etonitazene, 5 mcg/ml versus distilled water) were made at intervals up to 434 days following abrupt withdrawal morphine (from a daily maintenance dose level 200 mg/kg i.p.) in one group rats (“postaddicts”) termination i.p. injections saline control (“normals”). 2. During the first five after injections, signs primary abstinence observed “postaddict” rats: transient decrease consumption increase frequency. 3. Secondary morphine-abstinence phenomena, consisting signicantly greater slightly higher (compared with normal rats) over 7th–23rd post-injection days. Thereafter, these differences persisted, but not significant levels. 4. In no-choice test or on different occasions) conducted between 28th 37th “post-addict” drank significantly more etonitazene than water, whereas less water. 5. In free-choice tests period (morphine saline), no mean observed. In contrast, larger volumes solution every “relapse” through 336th again 406th post-withdrawal day (but 372nd 434th day). 6. It is concluded that rat “need” for an opioid persists about year morphine, this based long-term derangement homeostasis. although physiological characteristics such homeostatic differ relatively short protracted secondary periods. 7. The long persistence “relapse-tendency” previously physically dependent may be homeostasis coupled, perhaps, “interoceptive” conditioning generated during cycles from relief by “addiction” period, which internal sensorial effects opioids while receiving injections; imbibed tests) acquire reinforcing properties.