Additional testing revealed that the inhibitory effect of both fibrates and phenoxy-herbicides on the T1R3 receptor is specific to humans. That is, the ability of these compounds to block the receptor did not generalize across species to the rodent form of the receptor.
Mosinger commented on the implications of the findings and noted the importance of testing chemicals intended for human use on human tissues. "The metabolic consequences of short- and long-term exposures of humans to phenoxy-herbicides are unknown. This is because most safety tests were done using animals, which have T1R3 receptors that are insensitive to these compounds," he said.
The ability of fibrate drugs to interact with T1R3 receptors also was previously unknown. The study findings suggest that these receptors might be an important pharmacological target of first-generation fibrates, such as clofibrate, which were believed to act on a different receptor to affect lipid metabolism. Newer fibrate drugs are more specific for the second receptor and interact less with the T1R3 receptor.
Mosinger points out that little is known about how T1R3 blockade affects hormone levels and metabolism. "Given the number of compounds used in agriculture, medicine and the food industry that may affect human T1R3 and related receptors, more work is needed to identify the health-related effects of exposure to these compounds," he said.
|Contact: Leslie Stein|
Monell Chemical Senses Center