Tamaddonfard Esmaeal, Tamaddonfard Sina, Cheraghiyan Siamak
Department of Basic Sciences, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran.
DVM Student, Faculty of Veterinary Medicine, Urmia Branch of Islamic Azad University, Urmia, Iran.
Vet Res Forum. 2018 Fall;9(4):329-335. doi: 10.30466/vrf.2018.33104. Epub 2018 Dec 15.
Vitamin B modulates pain at the local and peripheral levels. This study has investigated the effects of intracerebroventricular (ICV) injection of vitamin B on themuscle pain. We used diclofenac (cyclooxygenase inhibitor) and naloxone (opioid receptors antagonist) to clarify the possible mechanisms. For ICV injections, a guide cannula was implanted in the left lateral ventricle of the brain. Muscle pain was induced by intramuscular injection of formalin (2.50%; 50 µl) in the right gastrocnemius muscle and the number of paw flinching was recorded at 5-min blocks for 60 min. Locomotor activity was performed using an open-field test. Formalin induced a biphasic pain. Vitamin B (1.25, 2.50, 5.00 and 10.00 µg per rat) and diclofenac (12.50 and 25.00 µg per rat) significantly reduced both phases pain intensity. Significant antinociceptive effects were observed after combined treatments of diclofenac (6.25 and 12.50 µg per rat) with vitamin B (0.63 and 2.50 µg per rat), respectively. Prior ICV injection of naloxone (10.00 µg per rat) prevented vitamin B (10.00 µg per rat) and diclofenac (25.00 µg per rat) induced antinociceptive effects. All the above-mentioned chemicals did not alter locomotor behavior in an open-field test. The present results showed that the cyclooxygenase pathway and opioid receptors may be involved in the central antinociceptive effect of vitamin B. In addition, opioid receptors might be involved in diclofenac-induced antinociception.
维生素B在局部和外周水平调节疼痛。本研究调查了脑室内注射维生素B对肌肉疼痛的影响。我们使用双氯芬酸（环氧化酶抑制剂）和纳洛酮（阿片受体拮抗剂）来阐明可能的机制。对于脑室内注射，将引导套管植入大脑左侧脑室。通过在右腓肠肌内注射福尔马林（2.50%；50微升）诱导肌肉疼痛，并在60分钟内以5分钟为间隔记录爪部抽搐次数。使用旷场试验进行运动活动测试。福尔马林诱导双相疼痛。维生素B（每只大鼠1.25、2.50、5.00和10.00微克）和双氯芬酸（每只大鼠12.50和25.00微克）均显著降低两个阶段的疼痛强度。分别在双氯芬酸（每只大鼠6.25和12.50微克）与维生素B（每只大鼠0.63和2.50微克）联合治疗后观察到显著的镇痛作用。预先脑室内注射纳洛酮（每只大鼠10.00微克）可阻止维生素B（每只大鼠10.00微克）和双氯芬酸（每只大鼠25.00微克）诱导的镇痛作用。上述所有化学物质在旷场试验中均未改变运动行为。目前的结果表明，环氧化酶途径和阿片受体可能参与维生素B的中枢镇痛作用。此外，阿片受体可能参与双氯芬酸诱导的镇痛作用。
