Effect of morphine dependence and abstinence on the expression of B-cell Lymphomal-2 in Sprague-Dawley rats / 重庆医科大学学报

ABSTRACT

Objective:To investigate the expression of Bcl-2 in rat brain during dependence and withdral state.Methods:The rats were rendered dependent by subcutaneous injections of increasing doses of morphine from 10 to 80 mg/kg for 5 consecutive days.The rats as controls were administered with same volume of normal saline.The expression of Bcl-2 mRNA was assayed with digacin-labelled Bcl-2 cDNA probe by in situ hybridization and the levels of Bcl-2 protein were measured by immunohistochemistry.Results:The evels of Bcl-2 and their mRNA in prefrontal cortex,locus coeruleus,hippocampus and ventral tegmental area significantly decreased as comparied with that in control rats after chronic administration of morphine and naloxone administration.However,Bcl-2 and their mRNA in nucleus accumbens of rats in withdral state were markedly higher than that in nucleus accumbens of morphine dependent rats.Conclusion:Chronic exposure to morphine appears to induce modification of the expression of Bcl-2 mRNA and their protein of rats in the rat brain,which contributes to the development of morphine dependence.