Naim Akhtar Khan
UPRES 4183 Lipides & Signalisation Cellulaire, Faculté des Sciences de la Vie, Université de Bourgogne, Dijon 21000, France Physiologie de la Nutrition, UMR INSERM U866, Agro-Sup, ENSBANA, Dijon 21000, France

Abstract:

It has been well propounded that there exists five basic taste modalities, e.g., sweet, sour, bitter, salty and umami.  Recent compelling evidence from rodent and human studies raise the possibility for an additional sixth taste modality devoted to the perception of lipids. A number of studies have recently suggested that lingual CD36, a glycoprotein, mainly expressed by circumvallate papillae of the tongue, might be implicated in the perception of dietary fat taste.

Our recent studies have not only supported the existence of the 6th taste modality, destined for the perception of fat, but also explored the intracellular signalling mechanisms, involved in this phenomenon. We have shown that lingual CD36, after activation by free fatty acids, induces increases in free intracellular calcium concentrations, ([Ca2+]i), phosphorylation of protein-tyrosine kinase (PTK) and release of the neurotransmitters like serotonin and nor-adrenaline into synaptic clefts. This signalling cascade is likely responsible for physiologic responses, induced by the detection of lipids in the oral cavity. Our results may help understand the lipid-mediated regulation of feeding behaviour which is very critical in the development of several diseases like obesity and other metabolic disorders. Besides, the lingual CD36 might be a target for controlling feeding behavior of obese subjects.