Evidence that healthy human gingiva contains functionally heterogeneous fibroblast subpopulations.

Six mass cultures of human fibroblasts derived from a single biopsy of a normal gingival papilla tip were studied with regard to their protein, collagen and glycosaminoglycan synthesis in vitro, using incorporation of radiolabelled substances. The proliferation rates, replicative life-spans and cell-size distributions of these mass cultures were determined. There were significant differences among the 6 cultures and these differences persisted throughout numerous cell replications in vitro. It is suggested that functional heterogeneity exists among phenotypically stable fibroblast subpopulations or subpopulation mixtures from normal tissue. The concept of participation of fibroblast subpopulations in disease pathogenesis is supported by these preliminary findings.