ABSTRACT
To clarify whether hypercalcemia after injection of Pb to rats is due to biological bone resorption or physicochemical mineral dissolution, the effect of lead (Pb) on release of previously incorporated 45Ca in organ culture was investigated. Pb at 50 microM and above stimulated the release of 45Ca and hydroxyproline (Hyp). Pb did not stimulate 45Ca release from the bones inactivated by freezing and thawing. Eel calcitonin (ECT), bafilomycin A1 and scopadulcic acid B (SDB) inhibited Pb-stimulated 45Ca release. These results indicate that Pb-induced 45Ca release is due to osteoclastic bone resorption. Pb-stimulated bone resorption was inhibited by indomethacin and flurbiprofen. Pb stimulated the release of prostaglandin E2 (PGE2) from the bones into the media. There was significantly high correlation between 45Ca and PGE2 release. Pb-induced bone resorption was inferred to be mediated by PGE2. From these results, it was suggested that hypercalcemia after Pb injection might be caused by biological bone resorption.
Subject(s)
Bone Resorption/chemically induced , Lead/toxicity , Macrolides , Animals , Anti-Bacterial Agents/pharmacology , Calcitonin/pharmacology , Calcium/metabolism , Dinoprostone/biosynthesis , Hydroxyproline/metabolism , Mice , Organ Culture TechniquesABSTRACT
Three major neutrophil chemotactic peptides belonging to the interleukin-8 (IL-8) family were purified to homogeneity from the conditioned medium of the IL-1 beta-stimulated human gingival fibroblasts culture. On the basis of their molecular masses and NH2-terminal amino acid sequences, these three neutrophil chemotactic factors were identical to melanoma growth stimulatory activity-alpha (MGSA/gro-alpha), MGSA/gro-gamma and Ala-Val-Leu-Pro-Arg-IL-8 (AVLPR-IL-8), each belonging to the IL-8 family. It has been shown by the chemotaxis studies in vitro that the chemotactic activity of MGSA/gro-gamma is similar to that of MGSA/gro-alpha for both human and rat neutrophils, while AVLPR-IL-8 is chemotactic for human neutrophils but not for rat neutrophils. The in vitro findings were supported by the histological studies in vivo on the intradermal injection of either MGSA/gro-alpha or AVLPR-IL-8 into the back of the rats. The results obtained in the present experiment suggest that human gingival fibroblasts play an important role in gingival inflammation through the production of neutrophil chemotactic factors newly characterized as the IL-8 family in response to inflammatory chemical mediators including IL-1 beta.
Subject(s)
Chemokines, CXC , Cytokines/metabolism , Fibroblasts/metabolism , Gingiva/cytology , Intercellular Signaling Peptides and Proteins , Interleukin-1/pharmacology , Interleukin-8/metabolism , Amino Acid Sequence , Cells, Cultured , Chemokine CXCL1 , Chemotactic Factors/analysis , Chemotactic Factors/metabolism , Child , Culture Media, Conditioned/pharmacology , Cytokines/analysis , Dose-Response Relationship, Drug , Electrophoresis, Polyacrylamide Gel , Fibroblasts/cytology , Fibroblasts/drug effects , Gingiva/drug effects , Gingiva/metabolism , Growth Substances/analysis , Growth Substances/metabolism , Humans , Interleukin-8/analysis , Male , Molecular Sequence Data , Neutrophils/cytology , Neutrophils/metabolismABSTRACT
An in vitro phagocytosis assay of adherent cells of 12 palatine tonsils (7 children's and 5 adults' cases with persistent angina) was performed by use of flow cytometry (FCM), using fluorescent latex particles (FLP). The mean value of the percentages of phagocytic cells in the children's group (81.4%) was higher than that in the adults' group (64.0%). In addition, separate immunocytochemical stainings with each antibody--Anti-Leu-M5, OKDR, OKT6, S-100, and lysozyme--were made on smear preparations of a child's and an adult's tonsillar adherent cells after incubation with FLP. By use of the light microscope, the percentages of phagocytic cells in relation to positive cells for each antibody were calculated. The lysozyme positive cell proved to have the highest percentage of phagocytic cells. Then, the average number of phagocytized FLP in one positive cell for each antibody were calculated. With regard to the lysozyme positive cell, this cell proved to have the highest average number of FLP.
