[A method for the quantitative assessment of the withdrawal syndrome in morphine-dependent rats]

The evaluation of strength of morphine withdrawal syndrome in rats after the 17th day i. p. morphine administration is proposed as calculation of individual indexes in "open field" test. It is found, that injection 1, 5 or 10 mg/kg of morphine 30 min before testing, decreases the withdrawal syndrome in dose dependent manner. Disappearance of particular withdrawal signs took place in different doses of morphine pretreatment. According to this effect all the signs were divided into four groups and signs of each group were given by the specificity coefficient (from 0 to 3). The total individual index of the withdrawal syndrome was calculated as a sum of particular signs, multiplied by the particular coefficient. Specificity of significant signs decrease according to the order: "wet dog" shakes, diarrhea, writhings, dyspnea, paw shakes, ptosis, piloerection and teeth chattering.