||Keisuke Sanematsu, Yuki Nakamura, Masatoshi Nomura, Noriatsu Shigemura, Yuzo Ninomiya, Diurnal variation of sweet taste recognition thresholds is absent in overweight and obese humans, Nutrients, 10.3390/nu10030297, 10, 3, 2018.03, Sweet taste thresholds are positively related to plasma leptin levels in normal weight humans: both show parallel diurnal variations and associations with postprandial glucose and insulin rises. Here, we tested whether this relationship also exists in overweight and obese (OW/Ob) individuals with hyperleptinemia. We tested 36 Japanese OW/Ob subjects (body mass index (BMI) > 25 kg/m2 ) for recognition thresholds for various taste stimuli at seven different time points from 8:00 a.m. to 10:00 p.m. using the staircase methodology, and measured plasma leptin, insulin, and blood glucose levels before each taste threshold measurement. We also used the homeostatic model assessment of insulin resistance (HOMA-IR) to evaluate insulin resistance. The results demonstrated that, unlike normal weight subjects, OW/Ob subjects showed no significant diurnal variations in the recognition thresholds for sweet stimuli but exhibited negative associations between the diurnal variations of both leptin and sweet recognition thresholds and the HOMA-IR scores. These findings suggest that in OW/Ob subjects, the basal leptin levels (~20 ng/mL) may already exceed leptin’s effective concentration for the modulation of sweet sensitivity and that this leptin resistance-based attenuation of the diurnal variations of the sweet taste recognition thresholds may also be indirectly linked to insulin resistance in OW/Ob subjects..
||Keisuke Sanematsu, Noriatsu Shigemura, Yuzo Ninomiya, Binding properties between human sweet receptor and sweet-inhibitor, gymnemic acids, Journal of Oral Biosciences , 10.1016/j.job.2017.05.004 , 2017.05.
||Keisuke Sanematsu, Masayuki Kitagawa, Ryusuke Yoshida, Satoru Nirasawa, Noriatsu Shigemura, Yuzo Ninomiya, Intracellular acidification is required for full activation of the sweet taste receptor by miraculin, Scientific reports, 10.1038/srep22807, 6, 22807, 2016.03.
||Keisuke Sanematsu, Yuko Kusakabe, Noriatsu Shigemura, Takatsugu Hirokawa, Seiji Nakamura, Toshiaki Imoto, Yuzo Ninomiya, Molecular Mechanisms for Sweet-suppressing Effect of Gymnemic Acids, Journal of Biological Chemistry, M114.560409 [pii] 10.1074/jbc.M114.560409, 289, 37, 25711-25720, 2014.09.
||Keisuke Sanematsu, Ryusuke Yoshida, Noriatsu Shigemura, Yuzo Ninomiya, Structure, function, and signaling of taste G-protein-coupled receptors, Current Pharmaceutical Biotechnology, １５, １０, 951-961, 2014.09.
||Sanematsu K, Horio N, Murata Y, Yoshida R, Ohkuri T, Shigemura N, Ninomiya Y., Modulation and transmission of sweet taste information for energy homeostasis., Ann N Y Acad Sci., 1170:102-6., 2009.07.
||Sanematsu K, Yasumatsu K, Yoshida R, Shigemura N, Ninomiya Y., Mouse strain differences in Gurmarin-sensitivity of sweet taste responses are not associated with polymorphisms of the sweet receptor gene, Tas1r3., Chemical Senses, 10.1093/chemse/bji041, 30, 6, 491-496, 30(6):491-6., 2005.07.