The effect of chick embryo amniotic fluid on sciatic nerve regeneration of rats

Abstract

The purpose of this experimental study was to evaluate the effect of chicken amniotic fluid (AF) on a cross section of rat sciatic nerves. Thirty adult male Sprague-Dawley rats weighing 275 to 300 g, were randomized into three groups treated with (1) amniotic fluid or AF (n=10), (2) normal saline or NS (n=10), and (3) sham surgery (n=10). The AF was aspirated from the amniotic cavity of incubating chick embryos at day 14. The sciatic nerve was exposed and sharply transected. Immediate epineurial repair was then performed. AF treated animals were given 2 ml/kg of the chick embryo AF subcutaneously, once daily, five times a week for up to 2 weeks. All animals were evaluated by sciatic functional index (SFI), electrophysiology, histology, and immunohistochemistry at days 28 and 56 after surgery. The SFI difference between AF and NS groups at days 21 and 28 after operation was statistically significant (P<0.05). The number of myelinated fibers in the AF group was significantly greater than that of the NS group at day 28 (P<0.05). At days 28 and 56 after operation, the nerve conduction velocity (NCV) mean of the AF group was faster than that of the NS group, but the difference was not statistically significant (P>0.05). The results of this study demonstrate that chick AF can enhance peripheral nerve regeneration.

Keywords: Amniotic fluid; Chick embryo; Nerve regeneration; Rat.

Fig. 1

SFI before and after nerve injury in AF, normal saline, and sham surgery groups. ^* Difference between AF treated and normal saline groups (P<0.05, t-test). Results presented as means ± SEM

Fig. 2

Total number of regenerated myelinated nerve fibers after sciatic injury (n=5 on day 28 and n=5 on day 56 for each group). ^* The difference between amniotic fluid treated and normal saline groups at days 28 and ^** 56 after operation, (P<0.05, One-Way-ANOVA). Results are presented as means ± SEM

Fig. 3

Immunohistochemical analysis of cross sections to the main axis of the regenerated nerve at day 56 after operation distal from the transected site of the sham surgery group (a), AF treated groups (b), and NM group (c). Positive staining of the myelin sheath-associated protein S-100 was observed. Regenerated nerve fibers containing Schwann cells, blood vessels, and myelinated axons throughout the tissue were present (scale bar 20 µm