TNF and ischemia: Compared with rats in Group 1, the levels of Cr, BUN, and CK in the serum of rats in Group 2 were significantly increased after 4 h of ischemia and 4 h of reperfusion, as well as the expression levels of TNF-α, IL-6, and IL-10; edema of the kidney interstitium and destruction of the renal tubular epithelial cells were also observed.