Bitter taste receptors found on human hearts

Melbourne: Smell and taste receptors normally found in the nose and mouth can also be present on the human heart, scientists have found. University of Queensland researchers found that around 12 taste receptors, particularly those that respond to bitter compounds, were expressed in human hearts. "This is quite remarkable, as the human genome only has 25 of these bitter taste receptors, and we wanted to find out why half of them were located in the heart," said Professor Walter Thomas, from The School of Biomedical Sciences.

"When we activated one of the taste receptors with a specific chemical that we all taste as bitter, the contractile function of the heart was almost completely inhibited. "While the underlying physiology behind this phenomenon remains unclear, this is now a major area of ongoing investigation," Thomas said.

The research team's primary focus is on how the heart grows normally as well as abnormally in disease. "After hypertension or a heart attack, the heart frequently undergoes compensatory growth in order to maintain the circulation of blood around the body," Thomas said.

"During laboratory tests, we were looking at all the genes that are regulated in the heart in this growth phase. "We found the rodent heart cells we were working with contained smell and taste receptors, which are normally considered to be only present in the nose and mouth," he said. "Using heart tissue from humans undergoing heart surgery, such as valve replacement and coronary arterial bypass, we replicated the rodent laboratory experiments and found taste receptors were also present in the human heart," he said.