Chromium effects on chondrocytic differentiation in vitro.
Uyeki-EM; Nakanishi-S; Fremming-L
J Toxicol Environ Health 1986 Sep; 19(1):137-145
The micromass culture technique of Solursh was used to determine whether hexavalent chromium (7440473) (Cr(IV)) can affect mesenchymal cells to differentiate into chondrocytes. A criterion for the sensitivity of such a system is the effective molar concentration of Cr(VI), how it compares with chromium's effect on sister chromatid exchange or on cell proliferation. Micromass cultures of chick limb bud mesenchymal cells were plated so that 20 microliters contained 400,000 cells. Addition of Cr(VI) to cultures of mesenchymal cells from the chick limb bud indicated that the products of chondrocytic differentiation are more sensitive to the noxious effects of chromium than is cell proliferation. When Cr(VI) was added daily to the cultures, the most sensitive period was the interval from day one to day two. At one hour and again at 24 hours after the start of the culture, ADP ribose transferase activity was high. There was also a rapid decrease in the activity of this enzyme between 24 and 48 hours, followed by a slower decline. Elevated ADP-ribose-transferase levels were maintained throughout the entire experimental period when Cr(VI) was added to the culture medium. The presence of 1.0 micromolar or higher of Cr(VI) apparently favors a balance of events toward nucleolytic action as opposed to repair of damage.
JTEHDS; NIOSH-Publication; NIOSH-Grant; Chromium-compounds; Chromosome-damage; Genetic-disorders; Laboratory-animals; Metallic-poisoning; Carcinogenicity; In-vitro-studies
Pharmacology University of Kansas 39Th St at Rainbow Blvd Kansas City, Kansas 66103
Journal of Toxicology and Environmental Health
University of Kansas Col Hlth Sci & Hosp, Kansas City, Kansas