Streptozotocin-Induced Pro-Inflammatory Response in Rat Blood and its Attenuation by External Albumin Administration

Previous report has suggested that the albumin levels were reduced in the peripheral blood mononuclear cells (PBMCs) and consequently oxidative stress was elevated in streptozotocin (STZ)-induced diabetic rats as albumin is the predominant antioxidant in plasma. In this study, we suggest that the levels of pro-inflammatory cytokine such as interleukin-6 (IL-6) and tumor necrosis factor-${\alpha}$ ($TNF-{\alpha}$) were increased by approximately 3.4- and 2.9-fold, respectively, in the serum of STZ-diabetic rats, compared to those of normal rat. In addition to the cytokines, the levels of C-reactive protein (CRP) were also about 3.6-fold higher, indicating that STZ induced a pro-inflammatory response in rat blood. However, when purified rat albumin was externally co-administrated with STZ through the tail vein, the serum levels of IL-6, $TNF-{\alpha}$, and CRP were markedly reduced, although the values were still higher than those of normal (non-diabetic) rats. Albumin administration also decreased STZ-induced oxidative stress in serum and PBMCs. Moreover, the decrease in cytokine and CRP levels was dependent on the dose of injected albumin. These results suggest that STZ-induced pro-inflammation and oxidative stress in rat blood might be attenuated by treatment with exogenous albumin.