GROWTH AND VIABILITY OF SECONDARY HAIR-FOLLICLES OF THE ANGORA-GOAT CULTURED INVITRO

The viability of isolated secondary anagen hair follicles from Angora goats was studied in an in vitro tissue culture system. Intact hair fo llicles were isolated from the dermal layer singly or in groups using watchmakers' forceps under a dissecting microscope following removal o f both the epidermis at the basal layer and subcutaneous fat layers us ing a scalpel blade. The connective tissue sheath surrounding the foll icle and the dermal papilla in the bulb were left intact. The isolated follicles were maintained floating in supplemented Williams E medium and showed significant increases in hair shaft length over 96 h. The v iability of the cultured hair follicles was verified by the findings t hat (1) the rate of hair shaft elongation was similar to that occurrin g in vivo; (2) the pattern of DNA synthesis observed by autoradiograph y of [methyl-H-3]thymidine uptake was maintained in the isolated folli cles throughout culture; (3) the ATP content was significantly higher in growing follicles compared with that observed in freshly isolated f ollicles; and (4) Feulgen-stained preparations of fresh and maintained hair follicles confirmed the retention of mitotic activity in the mat rix cells of the bulb for a maximum of 120 h of maintenance.