Department of Pediatrics, School of Medicine, Taipei Medical University, Taipei, Taiwan.
Neurotoxicology. 2010 Sep;31(5):432-8. doi: 10.1016/j.neuro.2010.06.002. Epub 2010 Jun 12.
Maternal methamphetamine (MA) abuse during pregnancy has been proved to induce various impacts on the development of infant and child. In this study, we examined whether prenatal exposure to MA would affect the development of nociceptive system by measuring the responses to noxious stimulation in the developing rat. Adult female Sprague-Dawley rats received bi-daily subcutaneous injection of methamphetamine (5mg/kg) or isovolumetric normal saline since the day of mating till the day of delivery. Birth profiles of the offspring including birth length, weight, and body temperature were recorded during the first postnatal month. Mechanical withdrawal thresholds were measured by von Frey filaments on postnatal day (PND) 30 and 60, and hyperalgesic behaviors following plantar formalin injection (2%, 50 microl) were evaluated on PND 60. The birth body weight and length of rats born to MA-injected dam rats (MA group) were significantly lower than those of the control rats during the first postnatal month; however, their body temperature was significantly higher than those of the control rats during the first 3 days after birth. The MA group rats had significantly lower tactile withdrawal values in von Frey test and higher pain scores in the late phase of pain in the formalin test than those of the control rats. There is a gender difference of nociceptive hypersensitivity manifested as that the female MA group rats had significantly lower withdrawal thresholds and higher pain scores in response to formalin injection than the male MA group rats. These results suggest that prenatal MA exposure could predispose an alteration in the development of nociceptive neuronal network, which leads to a long-lasting status of hypersensitivity to pain stimulations in the offspring.
孕期母亲吸食冰毒已被证实会对婴儿和儿童的发育产生各种影响。在这项研究中，我们通过测量发育中大鼠对伤害性刺激的反应，来检验产前暴露于冰毒是否会影响伤害性感受系统的发育。成年雌性 Sprague-Dawley 大鼠自交配日起至分娩日，每天接受两次皮下注射冰毒（5mg/kg）或等容量的生理盐水。在出生后第一个月期间，记录了幼仔的出生特征，包括出生长度、体重和体温。在出生后第 30 天和第 60 天，通过 von Frey 细丝测量机械退缩阈值，在出生后第 60 天，通过足底福尔马林注射（2%，50 微升）评估痛觉过敏行为。出生时注射 MA 的母鼠（MA 组）所生幼鼠的出生体重和长度在出生后第一个月显著低于对照组；然而，出生后前 3 天，它们的体温显著高于对照组。在 von Frey 试验中，MA 组大鼠的触觉退缩值显著降低，在福尔马林试验中晚期的疼痛评分显著高于对照组。痛觉过敏的敏感性存在性别差异，表现为雌性 MA 组大鼠对福尔马林注射的退缩阈值和疼痛评分显著低于雄性 MA 组大鼠。这些结果表明，产前 MA 暴露可能使伤害性感受神经元网络的发育发生改变，导致后代对疼痛刺激的敏感性持续存在。
