Siegan J B, Sagen J
Department of Anatomy and Cell Biology, University of Illinois at Chicago, 60612, USA.
Pain. 1997 Apr;70(2-3):279-85. doi: 10.1016/s0304-3959(97)03335-6.
Previous reports have indicated that the implantation of adrenal medullary chromaffin cells into the spinal subarachnoid space can reduce both acute and chronic pain in several animal models. Recent findings suggest that acute and chronic pain alleviation may be mediated by distinct mechanisms. Since the formalin response is composed of an acute and tonic phase which can be pharmacologically distinguished, the ability of adrenal medullary implants to alter these responses was assessed. In rats with adrenal medullary transplants, both phases of the formalin response were attenuated, in contrast to control implanted animals. Suppression of the acute phase by adrenal medullary implants was reversed by the opiate antagonist naloxone, and partially reversed by the alpha-adrenergic antagonist phentolamine, suggesting that opioid peptides and catecholamines released by the implanted chromaffin cells contribute to the observed antinociception. However, neither antagonist altered the antinociceptive effects of adrenal medullary implants on the tonic phase of the formalin response. These results indicate that adrenal medullary implants in the spinal subarachnoid space alleviate acute and tonic pain via distinct pharmacologic mechanisms.
先前的报告表明，将肾上腺髓质嗜铬细胞植入脊髓蛛网膜下腔可减轻多种动物模型中的急性和慢性疼痛。最近的研究结果表明，急性和慢性疼痛的缓解可能由不同的机制介导。由于福尔马林反应由急性和强直期组成，这两个阶段在药理学上可区分，因此评估了肾上腺髓质植入物改变这些反应的能力。与对照植入动物相比，在肾上腺髓质移植的大鼠中，福尔马林反应的两个阶段均减弱。肾上腺髓质植入物对急性期的抑制作用可被阿片拮抗剂纳洛酮逆转，并被α-肾上腺素能拮抗剂酚妥拉明部分逆转，这表明植入的嗜铬细胞释放的阿片肽和儿茶酚胺有助于观察到的抗伤害感受。然而，两种拮抗剂均未改变肾上腺髓质植入物对福尔马林反应强直期的抗伤害感受作用。这些结果表明，脊髓蛛网膜下腔中的肾上腺髓质植入物通过不同的药理机制减轻急性和强直期疼痛。
