A common environmental pollutant that is known to have a potent effect on gene activity may be promoting obesity, according to Japanese researchers.
Tributyltin is known to affect cell receptors in animals and humans at very low concentrations. Its harmful effect on the liver and the nervous and immune systems of mammals is well documented, however recently scientists have discovered that it also has potent effects on retinoid X receptors (RXRs), cellular components that mediate the biological effects of retinoids (chemical compounds that are chemically related to vitamin A). When activated, RXRs switch on genes that promote the growth of fat cells and switch off those that promote the breakdown of fat (lipolysis). Taisen Iguchi and Yoshinao Katsu, of the Graduate University for Advanced Studies in Japan, write that tributyltin is a potent activator of RXRs, and could thus promote obesity by increasing fat storage.
The authors conclude: “The environment may play a significant role in obesity. Since the increase in obesity rates parallels the rapid growth in the use of industrial chemicals over the past 40 years, it is plausible and provocative to associate in utero or chronic lifetime exposure to chemical triggers present in the modern environment with this epidemic.”
Iguchi T, Katsu Yoshinao. Commonality in Signaling of Endocrine Disruption from Snail to Human. BioScience 2008;58:1061-1067. doi:10.1641/B581109
News release: Persistent pollutant may promote obesity. American Institute of Biological Sciences. December 1st 2008.
