[Immunohistochemistry study of calcitonin gene-related peptide and substance P levels between end-to-end and end-to-side neurorrhaphy].

To explore the changes of calcitonin gene-related peptide (CGRP) and substance P (SP) levels after end-to-end and end-to-side neurorrhaphy. Twenty female Wistar rats were divided into 4 experimental groups and control group. In the experimental groups, common peroneal nerves were transected on both sides. End-to-side coaptation was performed on the left, while end-to-end coaptation on the right. After 1, 2, 4 and 27 weeks, the rats were sacrificed, and immunoreactivities of CGRP and SP in suture sites, lumbar spine and dorsal root ganglia (DRGs) were evaluated respectively. The expression of CGRP and SP decreased in dorsal horn and DRGs within 1 week postoperatively. After 4-27 weeks, CGRP and SP in dorsal horn could return to almost normal level, but they had little recovery in DRGs. Although the trend of change between end-to-end and end-to-side was coincident, in most experimental groups, there existed differences in the dorsal horn between end-to-end and end-to-side. The sciatic nerve stained by acetylcholinesterase, SP, CGRP and PGP 9.5 showed that the fibers could pass through the suture site of either end-to-end or end-to-side. Nerve regeneration can be achieved by end-to-side neurorrhaphy, and the mechanism of sensory nerve recovery of these two methods is similar. But the recovery in end-to-side coaptation is insufficient to some degree.