Pharmacology, physiology and clinical application of pregnancy-induced analgesia

这是研究大鼠妊娠镇痛生理学的系列研究之一。本研究旨在探讨1型钙通道阻滞剂在妊娠镇痛中的作用。(1)观察鞘内钙通道阻滞剂维拉帕米对利达卡因和丁卡因腰麻的影响。雄性SD大鼠慢性植入腰椎鞘内导管。采用甩尾法(TF)和机械爪压法(MPP)分别测定大鼠的热痛觉阈值和机械痛觉阈值。采用改良的朗格曼量表评定患者的运动功能。鞘内注射利多卡因后，大鼠TF潜伏期延长，MPP阈值升高，运动功能评分增加，呈时间和剂量依赖关系。虽然鞘内注射维拉帕米没有表现出感觉或运动阻滞)，但利多卡因或丁卡因与Ver…联合使用与单独使用局麻药相比，更多的阿帕米产生更有效和更持久的抗伤害性感觉和运动阻滞。(2)我们研究了三种不同类型的钙通道阻滞剂(维拉帕米、地尔硫卓和尼卡地平)对利多卡因局部感觉阻滞的影响。采用标准甩尾(TF)实验对利多卡因诱导的大鼠局部传导阻滞的持续时间和程度进行量化。在获得基线TF试验后，两次100杯单独使用0.3%利多卡因，联合使用维拉帕米、地尔硫卓或尼卡地平。大剂量钙通道阻滞剂注射于尾基两侧。联合应用利多卡因和三种剂量的1型钙通道阻滞剂可显著增加周围神经水平的抗伤害性感受。(3)观察鞘内注射钙通道阻滞剂维拉帕米对大鼠妊娠镇痛的影响。采用甩尾实验评价热伤害性反应阈值。在妊娠大鼠中，Tf在妊娠晚期显著升高。鞘内注射维拉帕米可显著延长妊娠晚期的Tf。较少

This is one of serires of studies to examine the physiology of pregnacy-induced analgesia in rats. The main purpose of this study was to examine the effects of 1-type calcium channel blockers on pregnancy-induced analgesia.(1) This study was designed to investigate the effects of the intrathecal calcium channel blocker, verapamil, on the spinal anesthesia from lidacaine and tetracaine. Male Sprague-Dawley rats were chronically implanted with lumbar intrathecal catheters. Tail flick (TF) and mechanical paw pressure (MPP) tests were used to assess thermal and mechanical nociceptive threshold, respectively. Motor function was assessed using a modified Langerman's scale. Intrathecal lidocaine of tetracaine alone showed the prolongation of TF latency, the increase of MPP threshold, and the increase in motor function scale in a time-and dose-dependent manner. Although intrathecal verapamil alone demonstrated neither sensory nor motor block), the combination of lidocaine or tetracaine and ver … More apamil produced the more potent and prolonged antinociception and motor block when compared with local anesthetics alone. (2) We have studied the effects of three different types of calcium channel blockers (verapamil, diltiazem, and nicardipine) on local lidocaine sensory block. Standard tail flick (TF) test was employed to quantify the duration and dgree of local lidocaine-induced conduction block in rats. After obtaining baseline TF test, two 100mug of 0.3% lidocaine alone, a combination of verapamil, diltiazem, or nicardipine. and a large dose of calcium channel blockers were injected on opposite sites of the tail base. Coadministration of lidocaine and three doses of 1-type calcum channel blockers significant increases of antinociception at the level of the peripheral nerve. (3) The study was designed to examine the intrathecally administered calcium channel blocker, verapamil, on pregnancy-induced analgesia inrats. To assess thermal nociceptive threshold, tail flick test was emolyed. In pregnant rats, a significant increase in TF was demonstrated on late pregnancy. Intrathecally administered verapamil produced a significant prolongation of TF late in pregnancy. Less