Abstract
Cytokines are messengers that play a major role in mediating cellular functions to resist external invasion such as trauma and surgical intervention by maintaining physiological homeostasis. The amount of cytokines produced changes when the human body is exposed to such external invasion, suggesting a close relationship between cytokine levels and invasion. The purpose of this study was to investigate changes in serum cytokine levels in a mouse model of shinbone fracture by determining post-fracture IL-6, IL-10, and IL-1β levels over time. Male C57BL mice, aged 8 weeks, received intraperitoneal anesthesia with pentobarbital sodium, and an artificial unilateral fracture was made in the thighs of the mice. Fractures were confirmed using plain dental x-ray films. Cardiac blood sampling was performed at 1, 3, 24, 72, and 120 hours after fracture. Collected blood was coagulated and centrifuged to obtain serum samples. Enzyme-linked immunosorbent assay (ELISA) was used to determine serum levels of IL-6, IL-10, and IL-1β. The results showed that IL-6 level in the fractured mice peaked at 3 hours after fracture and was significantly higher at 3 and 24 hours, as compared to that in the control. IL-6 levels in the fractured mice were significantly lower at 24, 72, and 120 hours after fracture than the peak level observed at 3 hours. IL-10 level also significantly increased at 3 hours after fracture, indicating that its changes over time were very similar to those of IL-6 level. No significant differences were noted for changes in IL-lβ levels at any assessment time point. These results showed that serum levels of I1-6, indicating degrees of invasion, and IL-10, an anti-inflammatory cytokine, had a similar profile of changes in time course after a shinbone fracture. These contrastive cytokines were found to be released simultaneously at the early stage after fracture, and the release was observed for a short period of time, even if no treatment was provided.
