[Optimization of primary human eccrine sweet glands' isolation in vitro].

Objective: To optimize the methods of isolating human eccrine sweat gland cells in vitro so as to get efficiently primary human sweat glands.

Methods: The fresh and normal skin tissue was cut into pieces of microskin about 1mm3 and the following 3 group digestion buffer was applied to isolated gland cells. The digestion buffer of group A was the equivoluminal mixture of Trypsin-Ethylene Diamine Tetraacetic Acid (EDTA) and collagenase-II (2 mg/ml). The digestion buffer of group B was collagenase-II (2 mg/ml) traditionally and group C was Trypsin-EDTA. These three groups were placed into an incubator simultaneously and the emerging time of dissociated sweat glands was calculated. Sweat glands were sorted out and then placed in culture dish. The adherence and the growth of cells were observed. The proliferation index was detected by flow cytometry. The identification of cultured cells was performed by immunocytochemical staining.

Results: After digesting 30 min in group A and C, a very few of dissociated sweat glands were emerging. But after digesting for 2 h, there were lots of dissociated sweat glands emerging in group A rather than in group C. The emergence of dissociated sweat glands in group B would require at least 6 hours. After seeded in culture dishes, the sweat glands in group C couldn't adhere to the wall of dish, but the sweat glands in group A and B adhered very well and even grew like paving stones after 9 days. In addition, the proliferation index were (18 ± 4) % and (17 ± 6) % respectively, there was no statistical difference. The results of immunocytochemical staining showed that the cells expressed carcino-embryonic antigen (CEA) and cytokeratin 7(CK7) in group A and B.

Conclusion: Trypsin-EDTA combined with collagenase-II can shorten the time of isolating sweat gland cells and have no effect on cell activity and proliferation.