Activation of epidermal growth factor receptor in the early phase after renal ischemia-reperfusion in rat

In order to estimate a regenerative response in the early phase after renal ischemia-reperfusion in rat, we examined the time course of the activation of epidermal growth factor receptor (EGFR) as a response of signal transdu ction pathway after 45 min ischemia in kidney. The activation of EGFR was o bserved 5-30 min after the start of reperfusion. Simultaneously, superoxide anion/hydrogen peroxide generated in the mitochondrial fraction was elevat ed during the same period. On the other hand, the level of EGF decreased in a time-dependent manner. These results suggested that superoxide anion/hyd rogen peroxide generated during the ischemia-reperfusion other than EGF cou ld act as an activator for the EGFR, In summary, the activation of EGFR is important as a regenerative response at an early stage after the start of r eperfusion in ischemic kidney.