Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 22 May 1987:
Vol. 236. no. 4804, pp. 967 - 969
DOI: 10.1126/science.3576214
Prev | Table of Contents | Next

Articles

Science, Vol 236, Issue 4804, 967-969
Copyright © 1987 by American Association for the Advancement of Science

articles

Carbon tetrachloride at hepatotoxic levels blocks reversibly gap junctions between rat hepatocytes

JC Saez, MV Bennett, and DC Spray

Electrical coupling and dye coupling between pairs of rat hepatocytes were reversibly reduced by brief exposure to halogenated methanes (CBrCl3, CCl4, and CHCl3). The potency of different halomethanes in uncoupling hepatocytes was comparable to their hepatotoxicity in vivo, and the rank order was the same as that of their tendency to form free radicals. The effect of carbon tetrachloride (CCl4) on hepatocytes was substantially reduced by prior treatment with SKF 525A, an inhibitor of cytochrome P-450, and by exposure to the reducing reagent beta-mercaptoethanol. Halomethane uncoupling occurred with or without extracellular calcium and did not change intracellular concentrations of calcium and hydrogen ions or the phosphorylation state of the main gap-junctional protein. Thus the uncoupling appears to depend on cytochrome P-450 oxidative metabolism in which free radicals are generated and may result from oxidation of the gap-junctional protein or of a regulatory molecule that leads to closure of gap-junctional channels. Decreases in junctional conductance may be a rapid cellular response to injury that protects healthy cells by uncoupling them from unhealthy ones.


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Expression of CONNEXIN43 Is Highly Sensitive to Ionizing Radiation and Other Environmental Stresses.
E. I. Azzam, S. M. de Toledo, and J. B. Little (2003)
Cancer Res. 63, 7128-7135
   Abstract »    Full Text »    PDF »
Prevention of the down-regulation of gap junctional intercellular communication by green tea in the liver of mice fed pentachlorophenol.
K. Sai, J. Kanno, R. Hasegawa, J. E. Trosko, and T. Inoue (2000)
Carcinogenesis 21, 1671-1676
   Abstract »    Full Text »    PDF »
Role of gap junctions in inhibiting ischemia-reperfusion injury of rat gastric mucosa.
F. Iwata, T. Joh, F. Ueda, Y. Yokoyama, and M. Itoh (1998)
Am J Physiol Gastrointest Liver Physiol 275, G883-G888
   Abstract »    Full Text »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)