大鼠福尔马林实验中脊髓后角浅层内P物质和降钙素基因相关肽的变化

CHANGES OF SUBSTANCE P AND CALCITONIN GENE RELATED PEPTIDE IN THE SUPERFICIAL LAYERS OF THE SPINAL DORSAL HORN IN THE RAT FOLLOWING FORMALIN TEST

为研究福尔马林实验动物行为反应与脊髓内Ｐ物质（ＳＰ）和降钙素基因相关肽（ＣＧＲＰ）之间可能的相互关系，应用免疫组织化学方法结合图像分析技术，对福尔马林实验大鼠不同时程的脊髓后角浅层内ＳＰ、ＣＧＲＰ的含量进行了半定量分析，并与大鼠的行为反应分期进行了比较。结果显示：脊髓后角浅层内ＳＰ和ＣＧＲＰ的含量在福尔马林实验后的第１期反应（０～５ｍｉｎ）时迅速降低；在间歇期（５～２０ｍｉｎ）仍持续降低，在１５ｍｉｎ达最低值；间歇期后进入第２期反应（３０～６０ｍｉｎ）时，逐渐开始缓慢恢复，６０ｍｉｎ后恢复至正常水平，并开始逐渐增高，于９０ｍｉｎ达最高值。之后逐渐回落，在１２～２４ｈ又恢复至正常水平。

To investigate relationship betweeen bi phasic nociceptive response of formalin test and neuropeptides, substance P (SP) and calcitonin gene related peptide (CGRP), in the spinal cord of the rat, we used immunohistochemical method combined with a computer assisted image processing system and semi quantified the changes of SP and CGRP like immunoreactivities ( LI) in the superficial layers of the spinal dorsal horn in the rat at different surviving time after subcutaneously injected formalin into hindpaw on one side. The results were as follows: SP LI and CGRP LI in the superficial layers of the spinal dorsal horn were quickly reduced in the first phasic nociceptive response (0 5 min) after injection of formalin. During the intermission between the first and second phases (5 20 min), they were further reduced, and reached to a minimum at 15 min. In the second phasic nociceptive response (30 60 min), SP LI and CGRP LI in the superficial layers of the spinal dorsal horn were slowly recovered, and to the normal level at 60 min. Then they began to increase, and reached to a peak at about 90 min. After that, SP LI and CGRP LI were slowly decreased, and to normal level in a period of 12～24h. The present results suggest that release of SP and CGRP which could transmit nociceptive information in the superficial spinal dorsal horn might be involved in the bi phasic nociceptive response of formalin test.