Endogenous stem cell mobilization versus exogenous stem cell therapy in rat model of chronic kidney disease Chronic kidney disease (CKD) affects 14% of the world population and is still a major health problem despite advances in renal transplantation. Adipose-derived mesenchymal stem cells (AD-MSCs) can restore damaged renal cells, while granulocyte colony-stimulating factor (G-CSF) is known to mobilize hematopoietic stem cells from bone marrow to peripheral circulation. The aim of this study is to compare the effect of endogenous CD34+ cell mobilization with exogenous AD-MSCs administration in the treatment of a rat model of CKD, induced by a single IV injection of ADR at a dose of 5 mg/kg. Forty eight male albino Sprague Dawley rats were divided into 4 equal groups. GI: control negative, GII: control positive, GIII: rats received 2×106 iron-labeled AD-MSCs IV on day 5 after ADR injection, and GIV received SC injection of G-CSF for 5 consecutive days at a dose of 70 μg/kg. In each group, 6 rats were sacrificed after 28 days and the other 6 after 84 days. Renal functions were assessed by measuring serum creatinine, albumin, urea and 24-hour urinary protein level at days 0, 5, 28 and 84. HB level was measured at days 0 & 84. Oxidative stress markers malondialdehyde (MDA) and total anti-oxidant (TAO) were measured, in kidney tissue, at day 28. CD 34+ cells % was measured in peripheral blood at day 9 using flowcytometry and showed a marked increase in GIV compared to other groups. After scarification, kidneys were removed for histopathological assessment. Data are expressed as means + SD and compared by ANOVA. Results revealed that both ADSCs and G-CSF significantly and similarly improved the following parameters of renal function at day 84 (p< 0.05): serum creatinine was 0.48±0.08 & 0.48±0.08 mg/dl in GIII & GIV respectively compared to 0.74±0.09 mg/dl in GII, albumin was 3.84±0.25 & 3.98±0.29 gm/dl in GIII & GIV respectively compared to 2.2±0.2 gm/dl in G II, urea was 38.4±4.10, 41.0±6.04 mg/dl in GIII & GIV respectively compared to 80.40±6.11 mg/dl in GII, and 24-hour urinary protein level was 982±77.85 & 815.80±81.11 mg in GIII & GIV respectively compared to 2841.20 ±461.85 mg in GII. HB was 14.10±0.55, 14.90±0.74 gm/dl in GIII, GIV respectively compared to 11.50±0.5 gm/ dl in GII. Comparing GIII & GIV, using post-hoc tukey test, G-CSF treated group had less 24-hour urinary protein level and higher serum albumin (p< 0.05). Homing of iron labeled AD-MSCs was microscopically detected in kidney sections. MDA level were less in groups GIII 1.56±0.21 & GIV 1.48±0.19 compared to GII 2.28±0.08 U/mg kidney tissue (P<0.05). TAO level was significantly higher in GIII & GIV (48.40±8.62 & 40.63±11.09 U/mg kidney tissue respectively) compared to GII (18.20±1.68 U/mg kidney tissue) (P<0.05). We concluded that both stimulating endogenous hematopoietic stem cells by G-CSF is at least as effective therapeutic line as injecting exogenous ADSCs in CKD.