雄性和雌性大鼠的吗啡耐受性
Morphine tolerance in male and female rats.
作者信息
Holtman Joseph R, Sloan Jewell W, Wala Elzbieta P
机构信息
Department of Anesthesiology, University of Kentucky College of Medicine, Chandler Medical Center, 800 Rose Street, Lexington, KY 40536-0293, USA.
出版信息
Pharmacol Biochem Behav. 2004 Mar;77(3):517-23. doi: 10.1016/j.pbb.2003.12.020.
Several studies indicate greater sensitivity to morphine (MOR) analgesia in male compared to female rats under the acute dosing condition. The present study investigated whether the same sex difference in sensitivity persists in MOR-tolerant rats. MOR was administered chronically (7 mg/kg twice daily) until tolerance developed in each rat. Tolerant rats were treated randomly with higher graded doses of MOR (10-25 mg/kg). Analgesia (tail-flick test) and spontaneous motor activity (total locomotion) were measured. The present data confirmed previous studies showing a greater sensitivity to acute MOR in male than in female rats. However, the sex differences seen in MOR sensitivity were abolished in tolerant rats. The rate of acquisition of tolerance was similar in male and female rats. The analgesic response was not affected by motor depression.
多项研究表明，在急性给药条件下，雄性大鼠对吗啡（MOR）镇痛的敏感性高于雌性大鼠。本研究调查了在吗啡耐受大鼠中是否也存在同样的性别敏感性差异。对每只大鼠长期给予吗啡（7mg/kg，每日两次）直至产生耐受性。对耐受大鼠随机给予更高剂量梯度的吗啡（10 - 25mg/kg）。测量镇痛效果（甩尾试验）和自发运动活动（总运动量）。目前的数据证实了先前的研究，即雄性大鼠对急性吗啡的敏感性高于雌性大鼠。然而，在耐受大鼠中，吗啡敏感性的性别差异消失了。雄性和雌性大鼠的耐受性获得速率相似。镇痛反应不受运动抑制的影响。
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