Immunomodulatory role of leptin treatment in experimental sepsis caused by gram negative bacteria

To investigate the effect of leptin treatment on circulating inflammatory cytokines and on tissue damage in experimental rat model of gram-negative sepsis. Materials and methods: Adult male Wistar rats, 28 in total, were randomly divided into 4 groups (n = 7): sham, leptin, sepsis, and sepsis group treated with leptin (sepsis+leptin). Sepsis was induced by intraperitoneal (ip) injection of 2 × 1010 CFU of Escherichia coli ATCC 25922. Leptin and sepsis+leptin groups received a single dose ip 0.1 mg/kg leptin, while sham group received 1 mL of ip saline. Rats were sacrificed 24 h after the induction of sepsis. Blood samples, lung, and kidney tissues were collected for analysis. Results: The sepsis group had significantly higher serum TNF-a, IL-6, and endothelin levels than the sham group (P = 0.05, P < 0.001, P = 0.003, respectively). The sepsis+leptin group had significantly lower IL-6 and endothelin levels (P = 0.001 and P = 0.020, respectively), and higher lung and kidney tissue myeloperoxidase activities when compared with the sepsis group (P = 0.039, P = 0.033, respectively). Conclusion: According to our results, leptin has a profound influence on sepsis, and to some extent it restricts the inflammatory events in sepsis.