Generally speaking, cholesterol is not a word that conjures up positive connotations. High cholesterol is well known to be a risk factor for both heart attack and stroke. A recent Finnish study has identified a new cell mechanism that could increase levels of bad cholesterol.
Problems with the PXR
You probably have never heard of it, but the pregnane X receptor (PXR) plays a major role in your health. Specifically, the PXR is tasked with helping to regulate the liver’s drug metabolism. In addition, this nuclear receptor might also influence both blood pressure and glucose/lipid metabolism.
The activity of the PXR receptors can be altered by both drugs and foods, as well as by environmental chemicals. For example, PXRs can be activated due to the presence of an antibiotic medication known as rifampicin. A number of chemicals found in consumer products can have the same effect, including chemicals found in plastic additives and pesticides.
Armed with this information, a research team from Finland’s University of Oulu examined the relationship between PXR activity and the body’s levels of LDL cholesterol, often referred to as the “bad” form of cholesterol. They concluded that, when PXR receptors undergo an increase in activity, the body’s levels of LDL simultaneously rise.
An Environmental Issue?
“It has long been known that some chemical substances can affect human reproductive functions, for example, by disturbing the action of sex hormones. This is the so-called endocrine disruption theory,” stated lead researcher Jukka Hakkola, a University of Oulu Professor of Pharmacology. “Recently, evidence has also been obtained on the association of certain drugs and environmental chemicals with elevated cholesterol.”
The study authors don’t plan to stop here. Their next step is to determine how frequently PXR activity can be linked to the cholesterol-raising impact of medicines and chemicals commonly found in our environment. If they are successful in this regard, the team hopes to establish a reliable method of predicting how LDL levels are affected by various chemicals.