INFLAMMATORY CELLS IN RENAL REGENERATION

Much research has been performed to gain better insight into the regen eration process, responsible for the functional and morphological reco very after acute renal failure (ARF). Many investigators focused on en dogenously produced polypeptide growth factors as the major mediators of tubular epithelial cell proliferation. However arguments contradict ing this hypothesis have recently gained more support. Indeed, the ear ly decrease of renal epidermal growth factor (EGF) and insulinlike gro wth factor-1 (IGF-1) in different experimental models of ARF has been frequently shown at both the mRNA and protein level, while other growt h factors could not be shown to increase. Moreover the inaccessibility of the upregulated receptors for endogenously produced growth factors has encouraged research to seek alternative origins for the signals i nducing renal regeneration. The accumulation of mononuclear leukocytes in the renal interstitium is a striking observation in renal failure. Where the interstitial disease, recognized by the persistent intersti tial accumulation of leukocytes, is a better predictor of chronic rena l failure and developing fibrosis, ARF distinguishes itself by the dis appearance of the infiltrate when regeneration is complete. The existe nce of a regenerative potential provided by the network of inflammator y mononuclear leukocytes is supported by studies on tissue repair in d ifferent fields. This review discusses the infiltrating network of mon onuclear leukocytes as a major participant in the regeneration process after acute renal failure, including the approach which can be follow ed to investigate this hypothesis.