Genomic DNA was extracted from 25 mg renal cortex, skin, heart or tubular cells on column DNeasy blood and tissue kit (Qiagen). DNA quality was verified on Nanodrop 1000 (ThermoScientific). Amplification of genomic telomeres present in DNA was realized in a Light Cycler 480 (Roche) using SYBR green and 2.5 pmol of each specific probe: s CGGTTTGTTTGGGTTTGGGTTTGGGTTTGGGTTTGGGTT, as GGCTTGCCTTACCCTTACCCTTACCCTTACCCTTACCCT, or of a domestic gene, here 36B4 s ACTGGTCTAGGACCCGAGAAG, as TCCCACCTTGTCTCCAGTCT. Denaturation of 5 mn at 95 °C was followed by 30 cycles of development for heart and kidney extracts or 35 cycles for skin extracts. Every cycle consisted of 3 stages (denaturation 15 seconds in 95 °C, hybridization 20 seconds in 52 °C for telomeres or 56 °C for 36B4, strain 15 seconds in 72 °C). Fluorescence was measured at the end of every cycle. After an exponential phase, obtaining of a tray at the end of PCR allowed to calculate a cycle threshold (Ct) for every target DNA, reflection of their initial quantity. Finally, the specificity of PCR product was verified thanks to the curve of fusion realized at the end of PCR. Telomerase activity in kidney was performed with the Telotaggg PCR ELISA kit according to manufacturer’s instructions (12209136001, Roche).