TNF and ischemia: A massive increase in the blood levels of IL-1β and TNFα, typical inflammatory cytokines released by activated leukocytes, was already detectable after 1 day of ischemia (190.94±11.05 pg/ml and 34.60±2.65 pg/ml, respectively), as compared with the sham-operated animals (44.26±9.52 pg/ml and 5.40±2.30 pg/ml, respectively), and it was still maintained at 28 days post-operation, although at lower levels (Fig. 5B,C, respectively).