The effect of endotoxins and enzymes in vitro on the release of gingival histamine.
Gingival samples removed from fifteen Beagle dogs were sectioned into small pieces, parts of which served as the uncultured piece; the remaining pieces were organ cultured for four hours at 37 degrees C in MEM control, compound 48/80, endotoxins, protease, collagenase, hyaluronidase, trypsin and chymotrypin media. Uncultured and cultured tissues and spent media were analyzed spectrofluorometrically for histamine content. The uncultured gingiva contained a mean of 2.80 mug histamine/g of tissue and was considered to contain 100% total histamine available for release. The percentages of histamine released into the medium were 5.4% for culture control, 57.3% for compound 48/80, 5.4% for endotoxins, 77.3% for protease, 16.1% for hyaluronidase, 24 for collagenase, 39.3% for trypsin, and 36.5% for chymotrypsin. When compared to the culture control, all test substances showed statistically significant histamine release (P less than 0.005 to P less than 0.0005) except for the endotoxins and for hyaluronidase (P greater than 0.05). The results demonstrate (1) that gingiva contains a potential source or reservoir of histamine, presumably in mast cells, and when appropriately challenged in vitro can release this histamine; (2) no direct effect of endotoxins on histamine release in vitro, (3) that all enzymes tested except hyaluronidase resulted in significant histamine release. The results of this in vitro study support a thesis that enzymes are active in the early events of gingival inflammation.
D000818:Animals; D002918:Chymotrypsin / Q000494:pharmacology; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004731:Endotoxins / Q000494:pharmacology*; D004798:Enzymes / Q000494:pharmacology*; D005881:Gingiva / Q000378:metabolism*; D006636:Histamine Release / Q000187:drug effects*; D006821:Hyaluronoglucosaminidase / Q000494:pharmacology; D003012:Microbial Collagenase / Q000494:pharmacology; D010447:Peptide Hydrolases / Q000494:pharmacology; D014357:Trypsin / Q000494:pharmacology; D003189:p-Methoxy-N-methylphenethylamine / Q000494:pharmacology
D004731:Endotoxins; D004798:Enzymes; D003189:p-Methoxy-N-methylphenethylamine; D006821:Hyaluronoglucosaminidase; D010447:Peptide Hydrolases; D002918:Chymotrypsin; D014357:Trypsin; D003012:Microbial Collagenase