New York, June 3 (IANS): Ever wondered why your kitten is such a picky and fussy eater? This is because cat's taste receptors respond in a unique way to bitter compounds compared with human receptors.
All cats, from pets to wild tigers, are carnivores that consume little plant material. Domestic cats, however, may still encounter bitter flavours in food and medicines.
"We confront the challenge of 'finicky cats' every day. It is exciting to find an unexpected receptor response to bitter compounds that has never been described in the literature to date for any other species," said study co-author Nancy Rawson from AFB International, a US-based pet food flavour company.
The findings will help formulate appealing food for cats as well as enhancing the acceptability of their medications.
The teams at AFB International and biotechnology company Integral Molecular studied the behaviour of two different cat bitter taste receptors in cell-based experiments.
TAS2R38 is a bitter taste receptor in humans of which some people have "supertaster" variants that give them an extreme sensitivity to bitter compounds, explaining some people's strong aversions to broccoli and brussels sprouts.
Compared with the human TAS2R38 receptor, the cat version was tenfold less sensitive to a key bitter compound PTC and did not respond at all to another bitter compound PROP.
The cat receptor also differed from the human taste receptor by being insensitive to saccharin, an artificial sweetener that tends to have a bitter aftertaste in humans.
"We were surprised to see that one of the cat taste receptors responded to a more limited range of bitter compounds compared to humans, suggesting that cats may be detecting a narrower, or at least a different, repertoire of bitter-tasting compounds," said co-author Joseph Rucker from Integral Molecular.
These insights could be instrumental in formulating appetising food for household cats as well as designing masking agents to enhance the acceptability of medications.
The research was published in the open access journal BMC Neuroscience.