Fig. 4

Probenecid inhibits both human and cat TAS2R38 and TAS2R43 response. To determine whether probenecid inhibited cat TAS2R38 and TAS2R43, the ability of both cat and human receptors to stimulate calcium flux was measured as above in the absence (−) of probenecid and after pre-incubation for one hour with probenecid at 1 mM (+). (a) Both human and cat TAS2R38 responses to PTC were inhibited completely by probenecid. Both human and cat TAS2R43 responses to aloin (b) and denatonium (c) were inhibited by probenecid. (d) The receptor-specific nature of probenecid inhibition was demonstrated by its stimulation of observed flux by human TAS2R31 response to saccharin [12]