Effects of stem cells and granulocyte colony stimulating factor in reperfusion injury.

INTRODUCTION: Bone marrow-derived stem cells have a potential capacity to differentiate and accelerate recovery in injured sites of body. Also, factors like granulocyte colony stimulating factor (GCSF) can promote their mobilization to the injured sites. We aimed to investigate the role of GCSF as an alternative therapeutic option instead of mesenchymal stem cells (MSCs) in reperfusion injury. MATERIALS AND METHODS: Twenty-nine rats with induced reperfusion injury were divided into 3 groups to receive MSC, GCSF, or nothing (control). Kidney function was assessed by blood urea nitrogen and serum creatinine levels. Histological grading was performed to evaluate the extent of tubular injury and the rate of recovery. RESULTS: All the rats reached recovery after 14 days. Rats in the MSC group reached early functional and histological recovery compared to the controls on the 7th day of the study (P = .01 and P = .02, respectively). Compared to the control group, the GCSF group showed a more significant histological recovery on the 7th day (P = .04), but kidney function was ameliorated on the 14th day (P = .04). Both the GCSF and control groups had a significant number of CD34+ cells, which were detected by flow cytometry on the 7th day after reperfusion injury. CONCLUSIONS: We found therapeutic effects following administration of both MSC and GCSF which was more evident with MSC in the setting of reperfusion injury. More investigation is required to find optimal time, dose, and route of administration as well as other possible contributing factors.

An established rat model of inducing reversible acute tubular necrosis.

INTRODUCTION: Acute tubular necrosis (ATN) is a challenging problem that still requires to be studied in animal models. Our aim was to prepare an established experimental model of inducing reversible ATN in rats by determining the optimum duration of ischemia induction to the kidney. MATERIALS AND METHODS: Twenty-four hour after nephrectomy of the right kidney and clamping the pedicle of the left kidney for durations ranging from 10 to 55 minutes, the kidney function and the histologic changes were evaluated. Accordingly, the optimum duration of clamping was determined and in the next step, it was considered for induction of reversible ATN in another group of rats. This group was followed up for 14 days and the pathologic course and function of the kidney were observed. RESULTS: Reversible ATN developed by 47-minute clamping of the renal pedicle. Blood urea nitrogen and serum creatinine levels were elevated up to threefold within 24 hours after the induction of ischemia and they decreased to their reference ranges after 12 and 6 days, respectively. In the histologic study of the kidneys, the least extend of injury was noted by the 14th day following the ATN induction. Even on the 14th day of the follow-up, some signs of ATN remained indicating that the tissue regeneration was not complete yet. CONCLUSIONS: To integrate the experimental models of ATN, a rat model with 47-minute clamping of the renal pedicle for induction of ischemia seems appropriate. The resultant ATN remains for a long duration, while kidney function is alleviated.