Yim A J, Miranda-Paiva C M, Flório J C, Oliveira C A, Nasello A G, Felicio Luciano F
Departamento de Patologia, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Orlando Marques de Paiva, 87, Cidade Universitária 05508-900, São Paulo, SP, Brazil.
Brain Res Bull. 2006 Jan 30;68(5):384-91. doi: 10.1016/j.brainresbull.2005.09.014. Epub 2005 Oct 12.
Pre-mating treatment of female rats with morphine may have long-term effects. In this study, we analyzed the effects of two types of morphine sulfate pre-treatment: during pre-mating (5.0 mg/kg on alternate days for a total of seven doses) and during pregnancy (3.5 mg/(kgday) for 5 days starting on day 17 of pregnancy during early lactation. In order to evaluate possible morphine-induced behavioral changes, dams were tested for maternal behavior and locomotor activity during early lactation, and striatal and hypothalamic concentrations of dopamine and their metabolites and serum levels of corticosterone were measured. Maternal behavior was disrupted only in animals treated with morphine sulfate during pregnancy and challenged acutely (1.5 mg/kg) during lactation. Pre-mating treatment with morphine sulfate-induced changes in responses with increased locomotor activity, striatal dopamine turnover and serum corticosterone levels. None of these parameters were affected by morphine sulfate pre-treatment during late pregnancy. These data suggest that morphine has specific long-term and sometimes addictive-like effects on actively reproductive female animals that vary with the pre-treatment period, late pregnancy being particularly sensitive for effects on maternal behavior.
用吗啡对雌性大鼠进行交配前处理可能会产生长期影响。在本研究中，我们分析了两种硫酸吗啡预处理的效果：交配前（每隔一天5.0毫克/千克，共七剂）和孕期（从妊娠第17天开始，在哺乳期早期连续5天，3.5毫克/（千克·天））。为了评估吗啡可能引起的行为变化，在哺乳期早期对母鼠进行母性行为和运动活动测试，并测量纹状体和下丘脑多巴胺及其代谢物的浓度以及皮质酮的血清水平。仅在孕期用硫酸吗啡处理且在哺乳期急性注射（1.5毫克/千克）的动物中母性行为受到干扰。交配前用硫酸吗啡处理会导致运动活动增加、纹状体多巴胺周转率和血清皮质酮水平的反应发生变化。这些参数均未受到妊娠晚期硫酸吗啡预处理的影响。这些数据表明，吗啡对处于活跃生殖期的雌性动物具有特定的长期影响，有时类似成瘾性影响，且这些影响会因预处理时期而异，妊娠晚期对母性行为的影响尤为敏感。
