Taste receptors — the proteins responsible for our ability to taste salty, sweet, and bitter foods — aren’t just present on our tongues.
Recently researchers are finding them present all over the body, from the mouth to the anus. Literally.
Taste receptors have been found in in the stomach, intestines, pancreas, lungs, and brain, the researchers said. But, we really don’t know what they are there for, study researcher Bedrich Mosinger, of the Monell Chemical Senses centre told Business Insider in an email:
“[The] function of taste receptors and signaling proteins outside of taste system is still unclear… [in some areas] they seem to be part of the chemical sensing of sugars or amino acids,” he said. “For the most part, though, full function of these extra-orally located taste receptors is unknown.”
New research, published today (July 1) in the journal Proceedings Of The National Academy of Sciences, found that these taste proteins for sweet and umami (the amino acid taste of soy sauce) not only exist in the testes, but they play an important role in mouse fertility.
They were originally trying to develop mice that didn’t have these receptors for use in taste-related studies, but soon realised that these mice were unable to reproduce if they were missing the taste receptors.
The researchers saw that if you either removed these receptors from the mouse testes or blocked their function, the mice became infertile.
“The males are sterile, their sperm count is low, and spermatozoa are not developed properly,” Mosinger said.
They drug that they used to block the taste receptors in the testes is of a class of drugs that are used to treat high blood cholesterol in humans. These drugs could be interfering with human fertility, they said.
Knowing that this interaction is important, it could make way for new treatments for infertility, or even lead to male birth control.
“Like much good science, our current findings pose more questions than answers,” study researcher Robert Margolskee, of the Monell Chemical Senses centre, said in a statement. “We now need to identify the pathways and mechanisms in testes that utilise these taste genes so we can understand how their loss leads to infertility.”