Use of immunohistochemical staining and ethylaldehyde acid-induced biomonoamine fluorescence for determining the distribution of sympathetic nerve terminals in human cervical capsule tissues / 中国微创外科杂志

Objective By using immunohistochemical staining of neuropeptide Y (NPY) and fluorescence of ethylaldehyde acid-induced biomonoamine mediators, to observe the distribution of sympathetic nerve terminals in human cervical capsule tissues, and to compare the two methods for further improvement. Methods Surgically removed joint capsule tissues from C 3~7 vertebrae of 17 cases were treated by paraffin imbedding with NPY immunohistochemical staining and frozen-section with fluorescence staining of ethylaldehyde acid-induced biomonoamine mediators. Slides were preconditioned by 1% KMnO4 and sections 15~20 ?m in thickness were made. The staining was conducted at 100 ℃ for 5 min firstly, and then at 80 ℃ for 2 min. We utilized adrenal glands of rats as positive control. The samples were observed under fluorescence microscope at 380~420 nm excitation wavelengths from a high-voltage mercury light source. Results NPY immunostaining findings indicated bulky positive materials in some arteriolar walls and nerve tracts of the joint capsules; biomonoamine mediators gave off fluorescence in green-yellow color under the induction of ethylaldehyde acid, which presented mostly as reticular or radial finely-broken fibers in vascular walls, basal laminae of the synovial membrane and dense connective tissues. The positive rates of NPY immunohistochemical staining were 70.6% (12/17) at C 3~4 intervertebral segment, 42.9% (6/14) at C 4~5 , 57.1% (8/14) at C 5~6 , and 50.0% (5/10) at C 6~7 , respectively, the total positive rate being 56.4% (31/55). When using the ethylaldehyde acid-induced biomonoamine fluorescence, the positive rates were 70.6% (12/17) at C 3~4 intervertebral segment, 93.8% (15/16) at C 4~5 , 66.7% (10/15) at C 5~6 , and 80.0% (8/10) at C 6~7 , respectively, the total positive rate being 77.6% (45/58). The positive rate was remarkably higher in ethylaldehyde acid-induced biomonoamine fluorescence than in NPY immunohistochemical staining, with statistically significant difference (?2=5.774,P=0016), especially at C 4~5 intervertebral segment (P=0.004). Conclusions Both the two methods can demonstrate the distribution of sympathetic nerve terminals, suggesting the presence of the terminals in human cervical capsule tissues. Modified ethylaldehyde acid-induced biomonoamine fluorescence offers a greater specificity.