Spinal cord injury (SCI) is an independent risk factor for
type 2 diabetes, and may induce
insulin resistance that leads to this disease. Studies have shown that greater
phosphoinositide 3-kinase (PI3K) activation in the hypothalamus leads to activation of the anti-inflammatory pathway, and the anti-inflammatory reflex may protect against
insulin resistance and
type 2 diabetes. However, the importance of this phenomenon in
type 2 diabetes pathogenesis after SCI remains elusive. In the present study, the expression of c-Fos in the hypothalamus of rats with SCI was elevated, and the hypothalamus injury was observer following SCI. Then we showed that SCI could induce increased levels of
blood glucose and
glucose tolerance in rats. Also, we found that SCI could damage the liver, adipocyte and pancreas, and led to
lipid position in liver. Western blots were used to detect the level of PI3K and p-Akt in the hypothalamus, and the results showed a significant downregulation of PI3K and p-Akt after SCI. Furthermore, to verify the activity of the PI3K signaling pathway, immunofluorescence was used to examine the expression of neurons positive for p-S6 (a marker of PI3K activation) after SCI. The results showed that the expression of p-S6-positive neurons decreased after SCI. In addition, the effect of SCI on peripheral
inflammation was also investigated. Following SCI, the serum levels of
tumor necrosis factor-α,
interleukin (IL)-1β, and
IL-6 increased. Collectively, our results suggest abnormality in
glucose metabolism after SCI, and demonstrate that SCI may impair activation of the PI3K signaling pathway in the hypothalamus. The reduced activity of the PI3K signaling pathway in the hypothalamus may lead to peripheral
inflammation, which might be the mechanism underlying the development of
insulin resistance and
type 2 diabetes following SCI.