AIM. To analyze whether the perfusion of kidneys with rhBMP-7 solution can better preserve tissue structure during cold ischemia up to 24 hours compared to commercially used UW solution. To analyze mechanisms of BMP-7 activity in tubular epithelial cells and its proficiency considering the time of cold ischemia. MATERIAL AND METHODS. The study was conducted on experimental model of cold ischemia in the rat kidneys. Kidneys were perfused with solutions as follows: saline, UW, rhBMP-7 and rhBMP-7 + UW. Kidneys were exposed to cold ischemia during 6, 12 and 24 hours. Spectrophotometric measurements of lipid peroxidation products and protein carbonyl content and levels of antioxidant enzymes activity were performed. Using Western blot were measured levels of expression of Hsp70, HIF-1alpha and activated caspase 3. With PCR method was analyzed the expression of mRNA BMP-7, TGF-β1, Smad1, Smad2, Smad3, Smad5 and Smad8. Immunohistochemical analysis was used to show expression and localization of BMP-7, TGF-β1, E-cadherin, α-SMA and PCNA. RESULTS. In tubular epithelial cells of the kidneys perfused with rhBMP-7 and rhBMP-7+UW solution the expression of BMP-7 and E-cadherin was observed still after 24 hours of cold ischemia. In the kidneys not perfused with rhBMP-7 high expression of TGF-β1 and α-SMA was found. Also, in the kidneys perfused with rhBMP-7 solution level of mRNA BMP-7 expression was increased. In the same tissue higher level of mRNA Smad1, Smad5 and Smad8 expression, molecules of intracellular BMP-7 signal pathway, was proved. The levels of mRNA BMP-7, Smad1, Smad5 and Smad8 expression were equally present during whole time of cold ischemia. Furthermore, in the kidneys perfused with rhBMP-7 solution there was no changes of levels of lipid peroxidation products and protein carbonyl content after 6 and 12 hours compared to kidney with sustainable function. The levels of lipid peroxidation products and preotein carbonyl content were higher in the kidneys treated with UW solution, while in the kidneys treated with rhBMP-7 solution their levels increased only after 24 hours of cold ischemia. After reperfusion with rhBMP-7 and rhBMP-7+UW solutions the levels of Hsp70 and HIF-1alfa expression were higher in relation to the kidneys perfused only with UW solution. Also, in the group of the kidneys perfused with the BMP-7 solution the level of activated caspase 3 expression was lower in relation with the kidneys perfused with UW solution. CONCLUSION. BMP-7 maintains the morphology of the kidney tissue better than UW solution during 24 hours of cold ischemia. BMP-7 prevents epithelial to mesenchymal transformation and consequently maintains epithelial phenotype of tubular cells, reduces cell apoptosis, stimulates the expression of protective factors and increases the antioxidant capacity of the tissue.