Hossein Rafiei - PhD candidate, Department of Biology, Faculty of Sciences, Shiraz Branch, Islamic Azad University, Shiraz,
Mehrdad Shariati - Associate Professor, Department of Biology, Kazerun Branch, Islamic Azad University, Kazerun, Iran -
Jina Khayatzadeh - Assistant professor, Department of Biology, Mashhad Branch, Islamic Azad University, Mashhad, Iran
Majid Farhoodi - Assistant professor, Razi Vaccine & Serum Research Institute (RVSRI ), Mashhad, Iran

Plumbum is one of the most sustainable heavy metals affecting irreversibly on many tissues of body. In this experiment, for investigating the differentiation of mesen-chymal stem cells (MSCs) to chondrocytes after rats fed with lead acetate II during 2 months, collagen type II expression gene was studied. Eighteen male Wistar rats were randomly divided 3 groups. In addition to libitum feed, control, tested I and tested II groups were respectively fed by distilled water, distilled water with the dose of 50 ppm lead acetate II and distilled wa-ter with the dose of 100 ppm lead acetate II during 2 months. Then, MSCs of rat femurs were isolated and placed in dulbecco’s modified eagle medium (DMEM). After suitable confluency, the medium was changed with chondrogenic medium for 21 days. Finally, collagen type II gene expression in differentiation process of MSCs was investigated by real time PCR. Collagen type II gene expression in tested II group had significantly reduction compared with tested I group. Also expression of collagen type II gene in control group was significantly more than tested I group. It seems, with respect to decreased collagen type II gene expression in MSCs of rats ex-posed to lead acetate II with the doses of 50 and 100 ppm, they are not suitable candidate for chondrogenic differentiation for therapeutic usages.

Mesenchymal Stem Cells, Lead acetate II, collagen type II, Chondrocytes, Chondro-genic Medium