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2918209 
Journal Article 
Carbon Tetrachloride-Induced Release of Calcium from Isolated Hepatocytes 
Ray, P; Moore, L 
1986 
1 
Toxicology
ISSN: 0300-483X
EISSN: 1879-3185 
NIOSH/00164476 
41 
2 
205-212 
The effects of carbon-tetrachloride (56235) on cellular calcium (7440702) was studied in isolated rat hepatocytes. Hepatocytes obtained from male Sprague-Dawley-rats were incubated with carbon-tetrachloride at concentrations up to 10 microliters/milliliter (micro/ml). The rate of release of calcium into the incubation medium was measured with a calcium ion selective electrode. The effect on endoplasmic reticulum calcium pump activity was evaluated. The effects of carbon-tetrachloride on the distribution of calcium in subcellular fractions of the hepatocytes were investigated. The calcium concentrations were measured by atomic absorption spectrophotometry. Hepatocytes rapidly released calcium. The release occurring within 30 seconds after the carbon-tetrachloride was added. The rate of efflux of calcium was dose dependent. Calcium pump activity was 46 percent inhibited after 1 minute incubation with carbon-tetrachloride and 80 percent inhibited after 5 minutes. Microsomal calcium content was 53 percent lower in hepatocytes exposed to carbon-tetrachloride. No significant increase in calcium content of other subcellular fractions was seen. The authors conclude that carbon-tetrachloride inhibits the endoplasmic reticulum calcium pump activity and reduces the amount of calcium associated with the microsomal fraction. Calcium released from an intracellular pool or pools by carbon-tetrachloride could initiate hepatotoxic changes.