EFFECT OF INCREASED EXTRACELLULAR CALCIUM AND CADMIUM ON HUMAN MONONUCLEAR PHAGOCYTIC CELLS (CALCIUM).
Contributors: University of California, Los Angeles.
Published: 1992
Number of pages: 165
Subjects: Health Sciences, Nursing.; Health Sciences, Immunology.; Health Sciences, Toxicology.
Description: Calcium is an essential nutrient ion for virtually all cells and is a key intracellular second messenger. It is unknown what the relationship is between increased extracellular calcium and the production of specific cytokines. Mononuclear phagocytic cells respond to foreign invasion by microorganisms and are components of the inflammatory response. This cell type is a major producer of interleukin-6 (IL-6), a pleiotropic cytokine. The purpose of this study was to determine whether there were changes in IL-6 production when a human monocytic cell line was exposed to a hypercalcemic environment. As a parallel system, a known immunotoxic compound, cadmium, was also tested. The human monocytic cell line THP-1 was exposed to varying molar concentrations of calcium (1 mM to 10 mM) and cadmium (0.01 mM to 0.1 mM). Cell culture supernatants were tested for IL-6 by the ELISA method. There were statistically significant lower levels of IL-6 at the 0.06 mM (p $<$ 0.05), the 0.8 mM and 0.1 mM cadmium concentrations (p $<$ 0.01), and the 8-10 mM calcium concentrations (p $<$ 0.01). To determine if these effects were due to an inhibition of transcription. IL-6 messenger RNA was analyzed via northern blot analysis. Results suggest that IL-6 mRNA levels are decreased at the upper calcium and cadmium concentrations. To determine the effect of the free cadmium and calcium ions, external cation chelators were added. Results indicate that addition of EDTA to the cadmium concentrations prevented the suppression of IL-6. These results provide new information regarding the immunosuppressive effects of increased extracellular calcium and cadmium on IL-6 in mononuclear phagocytic cells.
Notes: Source: Dissertation Abstracts International, Volume: 54-03, Section: B, page: 1332.

Thesis (D.N.SC.)--UNIVERSITY OF CALIFORNIA, LOS ANGELES, 1992.

School code: 0031.