The effect of dose on the intensity of dependence in morphine-dependent mice

• Main Authors: Jusoh, Ahmad Jamaluddin Al-Qasami, Syd Mohmad Faudzi, Syed Mohd Syahmi, Suhaimi, Maryam Saadah, Hashim, Ridzwan, Ridzwan, Irna Elina
• Format: Conference or Workshop Item
• Language: English; English
• Published: 2015
• Subjects: RS Pharmacy and materia medica
• Online Access: http://irep.iium.edu.my/45949/7/PPoint_UCSI_%28S%29.pdf; http://irep.iium.edu.my/45949/10/45949.pdf; http://irep.iium.edu.my/45949/

Introduction: Animal behaviour research is an important tool to study the addiction properties of addictive substances. The Conditioned Place Preference (CPP)paradigm is among the model used to achieve this purpose. It can be used to investigate a wide range of addiction related behaviour including intoxication and relapse potential. Since it involves a long cycle experiment, it is important to optimise the experimental conditions, but minimising any unnecessity. Therefore, in this study we aim to investigate the effects of different morphine dose (3.75 - 10 mg/kg) towards intensity of morphine dependence in adult Swiss albino mice. Methods: The mice were divided into four group (n=10-12 for each group), where each group received different doses of morphine and saline on alternate day for 6 days during conditioning phase. The intensity of dependence was measured during post-conditioning phase where the preference at the drug-paired compartment was calculated during a 15 minutes observation. Results: The result has shown that three out of four groups significantly developed dependence (P < 0.05). However, the group of mice that received highest morphine dose (10 mg/kg) did not develop dependence. When baseline was compared, it was found that the mice that received the lowest morphine treatment (3.75 mg/kg) shows the highest increment from their baseline (164.7±33.3 seconds), while the group that received 10 mg/kg morphine shows the lowest increment (119.0±31.6 seconds). The trend of increment at the drug-paired compartment shows a declining trend when the dose of morphine is increased. Conclusion: Therefore, it is concluded that the optimum dose of morphine that should be administered to the adult Swiss albino mice is around 3.75 mg/kg, provided that all other experimental conditions and protocols are maintained.