Objective: Glutamine has protective effects against renal injuries. This study was designed to explore the possible mechanism underlying the protections by examining the effects of glutamine on extracellular signal regulated kinase (ERK) and p38MAPK expression in the kidney in rats with endotoxemia.
Methods: One hundred and twenty-one 18-day-old Wistar rats were randomly injected with LPS (4 mg/kg; n=55), LPS (4 mg/kg)+glutamine (1 mL/kg) (n=55), or normal saline (control group; n=11). The two LPS groups were subdivided into five groups sacrificed at 2, 4, 6, 24 and 72 hrs after administration (n=11 each). ERK-2 and p38MAPK mRNA and protein expression in the kidney were measured by RT-PCR and immunohistochemistry.
Results: Compared to the control group, the mRNA and protein expression of both ERK-2 and p38MAPK in the LPS group significantly increased 2, 4, 6, 24 and 72 hrs after administration (P<0.01), and reached a peak at 6 hrs (P<0.01). In the LPS+glutamine group, the trend of ERK-2 and p38MAPK expression was similar to the LPS group but their expression levels were significantly lower than those in the LPS group at all time points (P<0.05 or 0.01).
Conclusions: Both ERK-2 and p38MAPK expression increased in young rats with LPS-induced endotoxemia. Glutamine alleviates renal injuries possibly by decreasing the expression of both.