Objective: This study investigated the expression of platelet-derived growth factor-B (PDGF-B) and its receptor-β (PDGFR-β) in rat cerebral cortex following sepsis and explored the possible underlying mechanism of neuro-protective effect of glutamine (Gln).
Methods: One hundred and twenty 10-day-old Wistar rats were randomly divided into three groups: a control group that received an intraperitoneal injection of normal saline (1 mL/kg), a sepsis group that received an intraperitoneal injection of lipopolysaccharide (LPS, 5 mg/kg), and a Gln treatment group that was administered with Gln (1.346 g/kg) 1 hr before LPS injection. The rats were subdivided into 5 groups sacrificed at 2, 6, 12, 24 and 72 hrs after LPS or normal saline injection (n=8). The distribution and expression of PDGF-B and PDGFR-β in the cerebral cortex were ascertained by immunohistochemistry and Western blot.
Results: The immunohistochemistry results showed that the PDGF-B and PDGFR-β expression in the cerebral cortex increased significantly in the Gln treatment group 72 hrs after LPS injection compared with that in the control and the sepsis groups. The Western blot results showed that the PDGF-B expression in the brain tissue in the sepsis and the Gln treatment groups were significantly lower than that in the control group 2, 6, and 12 hrs after LPS injection, while the Gln treatment group had increased PDGF-B expression compared with the sepsis group 12 and 72 hrs after LPS injection. Compared with the control group, the PDGFR-β expression in the brain tissue in the sepsis group increased 2 and 6 hrs after LPS injection but decreased significantly 72 hrs after LPS injection. There were no significant differences in the PDGFR-β expression between the Gln treatment and the control groups at all different time points.
Conclusions: Gln can increase the PDGF-B and PDGFR-β expression in the brain tissue of rats with sepsis. The increased PDGF-B and PDGFR-β expression might contribute to neuro-protective effects of Gln.