Pharmacology, physiology and clinical application of pregnancy-induced analgesia

本研究是大鼠妊娠镇痛生理学研究的系列研究之一。本研究的主要目的是探讨1型钙通道阻滞剂对妊娠镇痛的影响。(1)本研究旨在探讨鞘内钙通道阻滞剂维拉帕米对利多卡因和丁卡因脊髓麻醉的影响。雄性Sprague-Dawley大鼠长期植入腰椎鞘内导管。用甩尾（TF）和机械爪压（MPP）测试分别评估热阈值和机械伤害阈值。采用改良的Langerman量表评估运动功能。单独使用丁卡因的鞘内利多卡因表现为TF潜伏期延长、MPP阈值升高、运动功能量表升高，且呈时间和剂量依赖性。虽然鞘内单独使用维拉帕米既没有感觉阻滞，也没有运动阻滞)，但利多卡因或丁卡因联合使用维拉帕米，与单独使用局麻药相比，更多的维拉帕米产生更有效和更持久的抗痛觉和运动阻滞。(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）对局部利多卡因感觉阻滞的影响。采用标准甩尾（TF）试验量化利多卡因诱导大鼠局部传导阻滞的持续时间和程度。获得基线TF测试后，单独使用两100马克的0.3%利多卡因，维拉帕米、地尔硫卓或尼卡地平联合使用。大剂量的钙通道阻滞剂被注射到尾基的相反部位。利多卡因与三剂1型钙通道阻滞剂联合使用可显著增加周围神经水平的抗感觉作用。(3)本研究旨在探讨鞘内给药钙通道阻滞剂维拉帕米对妊娠镇痛的影响。采用甩尾试验评估热伤害性阈值。在怀孕大鼠中，TF在妊娠后期显著增加。鞘内注射维拉帕米可显著延长妊娠后期的TF。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