Although, we have not used concentrated culture supernatant and thus cannot completely rule out the therapeutic efficacy of culture supernatant. However, no therapeutic effect of culture supernatant in ARF even after its CCT239065 multiple injections in rats indicates that the improvement of renal functions in ARF rats is more likely to be due to fetal kidney cells, which may serve as a continuous source of renotropic factors in the local milieu of the kidney. Similarly other groups have also used multiple injections of unconcentrated culture supernatant indifferent diseases. Histopathological evaluation showed that the fetal kidney cells treated kidneys had attenuation of tubular damage with a quantitative assessment of renal tubular necrosis by Jablonski scoring showed a Jablonskis core grade of 1.38��0.16 in fetal kidney cells treated versus 3.43��0.35 in saline treated kidneys. Further, the PCNA assay revealed a significant increase in proliferation of tubular cells and TUNEL assay showed significantly reduced numbers of apoptotic cells in fetal kidney cells as compared to saline treated group. Similar to our observation, Kim et al. have shown that transplantation of early gestation stage fetal kidney cells into damaged kidneys in rats resulted insignificantly lower BUN levels and significantly greater levels of creat in ineinurine as compared to the control rats. Further, the transplanted rats exhibited kidney tissue reconstitution and the fluorescently labeled transplanted cells were detected in there constituted kidney tubules. However, transplantation of fetal kidney cells from a later gestation stage resulted in poor kidney structure formation. After72hours of cell infusion, the rapid recovery observed by us inrenal functions of fetal kidney cells treated rats may not be due to regeneration of damaged kidney tissues and hence we evaluated whether P7C3 infused fetal kidney cells mediaterapid recovery of renal function in ARF rats by paracrine mechanisms.We found that kidneys tissues of fetal kidney cells treated ARF rats have a lower mRNA expression of various pro-inflammatory cytokines including IL1��,TNF-�� and IFN-�� and protein expression of other potent inflammatory biomarkers including NF��B and ICAM-1 as well as higher mRNA expression ofIL-10, which is a potent anti inflammatory mediator.