Molecular mechanisms of the sedation and analgesia induced by xylazine on Wistar rats and PC12 cell

In veterinary clinics, xylazine is commonly used as a sedative, analgesic agent that produces muscle relaxation. In this study, we aimed to explore the mechanism of action of xylazine both in vivo and in vitro. After determing the optimal dose of xylazine, 35 male Wistar rats were divided into seven groups (n=5 per group), including a control group (saline) and xylazine administration groups. Then, at six time points after xylazine administration indicators were evaluated for changes. Moreover, PC12 cells were co-cultured with xylazine, and extracellular regulated protein kinase (ERK) siRNA and protein kinase A (PKA) siRNA were transfected into cells to identify changes of relevant indicators. Our data showed that xylazine influenced the level of adenosine triphosphate (ATP) ase and cyclic adenosine monophosphate (cAMP), and regulated the expression of GIuR1, ERK, PKA, cAMP-response element binding protein (CREB), and brain derived neurotrophic factor (BDNF) in the nervous system. However, xylazine did not significantly affect the expression of GluR2 and protein kinase C (PKC). Together, these results indicated that xylazine might exert sedation and analgesia by regulating the PKA/ERK/CREB signaling pathway.