[Cultivation and identification of follicular papilla cells from back skin of actual rat in vitro].

Objective: To establish more efficient method to isolate of dermal papilla cells (DPCs) from back skin of SD rats, and then to study the growth ability and characteristics of SD rat dermal papilla cells in vitro.
Method: DPCs were separated from back skin of SD rats according to the modified method of two-step enzymatic digestion. The DPCs morphological observation under inverted microscope, the growth kinetics by cells number, the cell cycle analysis by flow cytometry analysis and determine the surface epitopes by immunohistochemical staining and flow cytometry analysis.
Result: Cultured DPCs were similar to fibroblasts in appearance, but generally and periodically exhibited an aggregative growth pattern. The growth kinetics showed that the number of DPCs presented progressive increase in a logarithm mode in the first 3 days and entered into plateau after 9 days, P1, P3, P5 multiplication time was 68 h, 52 h and 36 h, respectively. The flow cytometrical analysis showed that DPCs of P1, P3, P5 G0/G1 stage were (90.21 +/- 5.13)%, (81.23 +/- 1.85)% and (75.16 +/- 5.32)%, respectively. G0/G1 stage cells became less following passage subculture and elongation of culture time, but most of the DPCs stayed resting stage still. The cultivated dermal papilla cells expression of alpha-smooth muscle and CD44 on cell surface was positive, CK and CD34 were negative.
Conclusion: DPCs can be separated by the modified method of two-step enzymatic digestion successfully. The cultivated dermal papilla cells vitro show the feature of stem cells and has important potentially as a new seed cell source for cell engineering.