Sagen J, Kemmler J E
Department of Anatomy and Cell Biology, University of Illinois, Chicago 60612.
Brain Res. 1989 Nov 13;502(1):1-10. doi: 10.1016/0006-8993(89)90455-1.
Recent work in our laboratory has demonstrated that the transplantation of adrenal medullary tissue into the spinal cord subarachnoid space can reduce pain sensitivity, particularly following nicotinic stimulation. This analgesia most likely results from the release of opioid peptides from the implanted chromaffin cells since it is blocked by the opiate antagonist naloxone. The purpose of the present study was to more directly measure opioid peptide release from adrenal medullary implants in the spinal cord using spinal cord superfusions. Basal levels of Met-enkephalin-like immunoreactivity (MELI) in spinal cord superfusates of animals with adrenal medullary implants was twice that in animals with control implants. The injection of nicotine further increased MELI release in adrenal medullary, but not control implanted animals. Both the basal MELI levels and the MELI levels following nicotine were correlated with reduced pain sensitivity in animals with adrenal medullary implants. Morphological studies revealed good long-term survival of grafted chromaffin cells. Results of this study suggest that it is possible to increase opioid peptide levels and concomitantly decrease pain sensitivity by the transplantation of adrenal medullary tissue into the spinal cord subarachnoid space.
我们实验室最近的研究表明，将肾上腺髓质组织移植到脊髓蛛网膜下腔可降低疼痛敏感性，尤其是在烟碱刺激后。这种镇痛作用很可能源于植入的嗜铬细胞释放阿片肽，因为它会被阿片拮抗剂纳洛酮阻断。本研究的目的是使用脊髓灌流法更直接地测量脊髓中肾上腺髓质植入物释放的阿片肽。有肾上腺髓质植入物的动物脊髓灌流液中，甲硫氨酸脑啡肽样免疫反应性（MELI）的基础水平是有对照植入物动物的两倍。注射烟碱进一步增加了肾上腺髓质植入动物而非对照植入动物的MELI释放。有肾上腺髓质植入物动物的基础MELI水平和烟碱注射后的MELI水平均与疼痛敏感性降低相关。形态学研究显示移植的嗜铬细胞长期存活良好。本研究结果表明，将肾上腺髓质组织移植到脊髓蛛网膜下腔有可能提高阿片肽水平并同时降低疼痛敏感性。
