Department of Psychology, University of Canterbury, Christchurch, New Zealand.
Pharmacol Biochem Behav. 2012 Aug;102(2):381-9. doi: 10.1016/j.pbb.2012.05.010. Epub 2012 May 24.
In order to assess the long-term behavioral consequences of exposing rats to methadone during gestation, lactation or both periods consecutively, pregnant Wistar dams were provided with drinking water containing approximately 2.39 mg/kg/day methadone. Soon after birth, litters of offspring were assigned to methadone-naïve foster mothers. Half of these foster mothers were then provided with drinking water containing methadone (approximately 2.86 mg/kg/day), while the other half received unadulterated water. Maternal weight gain, pregnancy duration, litter sizes, sex ratios and average pup weights were recorded. Following weaning on postnatal day (PND) 28, individual rats were weighed and inspected for physical abnormalities and stress reactions at PND20, 60 and 120. At these same ages, observations were also made of the rats' behavior in an emergence apparatus, and an open field. Apart from a smaller number of full-term pregnancies, there were no effects of any type of methadone treatment on physical measurements recorded at any age. Nor were there any behavioral effects of gestational methadone experienced on its own. However, methadone experienced during lactation (without gestational exposure) decreased emergence speed at PND30, and for all testing ages combined, increased open-field ambulation (males only), walking, rearing and occupancy of the center of the apparatus. Exposure to methadone during both gestation and lactation decreased emergence latencies at PND30 and, for all ages combined, decreased ambulation (males only), center occupancy and defecation. The subsequent behavioral effects of methadone were largely confined to lactational exposure and, when combined with gestational exposure, suggested increased anxiety.
为了评估在妊娠、哺乳期或这两个时期连续暴露于美沙酮对大鼠的长期行为后果，给怀孕的 Wistar 母鼠提供含有约 2.39 毫克/千克/天美沙酮的饮用水。出生后不久，将后代的幼崽分配给美沙酮未接触的寄养母鼠。其中一半的寄养母鼠随后提供含有美沙酮（约 2.86 毫克/千克/天）的饮用水，而另一半则接受未掺杂的水。记录母鼠体重增加、妊娠持续时间、产仔数、性别比和平均幼鼠体重。在 28 日龄断奶后，个体大鼠在 20、60 和 120 日龄时称重，并检查其是否有身体异常和应激反应。在相同的年龄，还观察了大鼠在出现装置和开阔场中的行为。除了足月妊娠的数量较少外，任何类型的美沙酮处理对任何年龄记录的身体测量都没有影响。妊娠期间单独接触美沙酮也没有行为影响。然而，哺乳期接触美沙酮（无妊娠暴露）会降低 30 日龄时的出现速度，并且在所有测试年龄中，增加开阔场的运动（仅雄性）、行走、站立和占据装置中心的次数。妊娠和哺乳期同时暴露于美沙酮会降低 30 日龄时的出现潜伏期，并且在所有年龄的综合影响下，会降低运动（仅雄性）、中心占据和装置中心的排便次数。美沙酮随后的行为影响主要局限于哺乳期接触，并且当与妊娠暴露结合时，提示焦虑增加。
