Leptin fluctuates in intestinal ischemia-reperfusion injury as inflammatory cytokine.

As leptin is an active mediator mainly secreted by adipose tissue and is closely related with energy metabolism, we evaluate both the changes of leptin levels in serum and adipose tissue with a concise radioimmunoassay and the changes of leptin mRNA expression in adipose tissue with RT-PCR, during the severe metabolic impediment in rat intestinal ischemia-reperfusion (I/R) injury. Results show that not only leptin levels in serum and adipose tissue but also its mRNA expression in adipose tissue undergo a fluctuation according to different injury times. Therefore, we conclude that leptin has a time-dependent response to acute inflammatory stimuli and acts as an anti-inflammatory cytokine.