Function of gingival fibroblasts and periodontal ligament cells in the presence of methyl mercaptan.
OBJECTIVE
This study examined the effects of methyl mercaptan, a product of the bacterial putrefaction of protein in periodontal pockets, on the function of cells in culture.


METHODS
Human gingival fibroblasts and periodontal ligament cells were exposed to a constant, continuous flow of methyl mercaptan in vitro. Control and test cultures were then examined for changes in intracellular pH, an event often associated with alterations in cellular function. Intracellular pH was determined by single-cell image analysis of cells loaded with a fluorescent, pH-sensitive dye. Periodontal ligament cells were also tested for changes in synthesis of total protein and fibronectin.


RESULTS
Test cells exhibited a consistent decrease in intracellular pH following exposure to methyl mercaptan. Measurements of total protein production showed that test periodontal ligament cell cultures produced approximately 30% less protein than control cultures (P < 0.05). Western-blot analysis of fibronectin in medium demonstrated that abnormal monomeric fibronectins were a major protein in test, but not in control, cell cultures.


CONCLUSIONS
Exposure to methyl mercaptan induced alterations in intracellular events that paralleled changes in extracellular matrix proteins. The observed changes in extracellular matrix proteins support the hypothesis that methyl mercaptan contributes to the progression of periodontal disease.
Johnson
P W
PW
Department of Stomatology, Faculty of Dentistry, University of California, San Francisco 94143, USA. madmacs@itsa.ucsf.edu
Lancero
H
H
D002478:Cells, Cultured / Q000187:drug effects / Q000378:metabolism; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D005353:Fibronectins / Q000096:biosynthesis; D005881:Gingiva / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D010513:Periodontal Ligament / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D010514:Periodontal Pocket / Q000378:metabolism; D013438:Sulfhydryl Compounds / Q000378:metabolism / Q000494:pharmacology*
D005353:Fibronectins; D013438:Sulfhydryl Compounds; C005231:methylmercaptan