RESUMEN
The effects of aging on the umami sensation were compared between the preference and neural responses from the greater superficial petrosal nerve (GSP innervating the soft palate) and the chorda tympani nerve (CT innervating the fungiform papillae) in the Sprague Dawley rat. A two-bottle preference test revealed that younger rats (5-12 weeks) preferred significantly 0.001 M 5'-inosine monophosphate (IMP), 0.01 M mono sodium glutamate (MSG), and binary mixtures of 0.001 M IMP+0.01 M MSG than deionized water. However, aged rats (21-22 months) showed no significant preference to these umami solutions compared to deionized water. Among the other four basic taste stimuli, there were no significant differences in preference between young and aged rats. Regardless of the age of the rat, neural responses from the GSP and CT produced robust integrated responses to all three umami solutions used in the two-bottle tests. These results indicate that the lack of preference to umami in aged rats is a central nervous system phenomenon and suggests that the loss of preference to umami taste in aged rats is caused by homeostatic changes in the brain incurred by aging.
Asunto(s)
Envejecimiento , Nervio de la Cuerda del Tímpano/fisiología , Inosina Monofosfato/farmacología , Gusto/efectos de los fármacos , Gusto/fisiología , Factores de Edad , Animales , Preferencias Alimentarias , Masculino , Paladar Blando/inervación , Ratas , Ratas Sprague-Dawley , Glutamato de Sodio/farmacología , Lengua/inervaciónRESUMEN
It is attempted to augment a coating resin with a bleaching effect to provide both short- and long-term whitening effects. Base resin containing sodium percarbonate (SPC) effectively bleached bovine teeth discolored by the Maillard reaction. SPC did not reduce Vickers hardness, but hardness in the hybrid material increased. The shear bonding strength of SPC-containing resin was low. No inflammation was apparent in hamster cheek pouch mucosa when exposed to SPC resin covered with a layer of base resin. H(2)O(2) was released into buffer from this resin, but when placed onto tooth tissue with a protective layer of base resin, penetration of H(2)O(2) into the pulp chamber was undetectable. It is concluded that SPC resin equipped with a bleaching aid can be safely used as a coating material for discolored teeth.
Asunto(s)
Materiales Biocompatibles Revestidos/química , Blanqueadores Dentales/uso terapéutico , Decoloración de Dientes/tratamiento farmacológico , Animales , Peróxido de Benzoílo/uso terapéutico , Bisfenol A Glicidil Metacrilato/química , Boratos/uso terapéutico , Peróxido de Carbamida , Carbonatos/química , Bovinos , Color , Colorimetría , Cricetinae , Recubrimiento Dental Adhesivo , Esmalte Dental/efectos de los fármacos , Pulpa Dental/efectos de los fármacos , Portadores de Fármacos , Dureza , Peróxido de Hidrógeno/química , Curación por Luz de Adhesivos Dentales , Masculino , Mesocricetus , Mucosa Bucal/efectos de los fármacos , Peróxidos/uso terapéutico , Ácidos Polimetacrílicos/química , Resistencia al Corte , Estrés Mecánico , Sulfitos/uso terapéutico , Blanqueamiento de Dientes/métodos , Blanqueadores Dentales/química , Urea/análogos & derivados , Urea/uso terapéuticoAsunto(s)
Nervio de la Cuerda del Tímpano/embriología , Sistema Nervioso/embriología , Paladar Blando/embriología , Papilas Gustativas/embriología , Papilas Gustativas/fisiología , Gusto/fisiología , Animales , Animales Recién Nacidos , Callithrix , Nervio de la Cuerda del Tímpano/metabolismo , Cricetinae , Mamíferos , Modelos Biológicos , Sistema Nervioso/metabolismo , Paladar Blando/metabolismo , Ratas , Papilas Gustativas/metabolismo , Factores de TiempoRESUMEN
The effect of soluble starch (acid-modified starch) on taste intensity was investigated in human subjects. Different concentrations of sucrose (Suc), six sweeteners, NaCl, quinine-HCl (QHCl) and citric acid (Cit) were dissolved in either distilled water (DW; standard) or starch solution (test solution). The solutions were presented to naive subjects and each subject was requested to taste and compare the sweetness intensity between the standard and test solutions based on a scale ranging from +3 (enhanced) to -3 (inhibited). A greater sweetness intensity occurred with Suc at different concentration (0.1-1.0 M) dissolved in soluble starch (0.125% to 4.0%) than with Suc in DW. Similarly, five other different products of soluble starch at 0.25 and 4.0% resulted in enhancement of sweetness for 0.3 and 1.0 M Suc. With the sole exception of the taste of 0.3 M Suc, sweet enhancement did not occur with 0.43 M fructose, 0.82 M glucose, 0.82 M sorbitol, 0.0037 M aspartame, 0.0042 M saccharin-Na or 0.016 M cyclamate. Neither the saltiness of NaCl (0.01-0.3 M), the bitterness of QHCl (0.00003-0.001 M) nor the sourness of Cit (0.0003-0.01 M) were affected by the soluble starch. These results suggest that the taste enhancing effects of soluble starch on Suc sweetness might depend not only on the taste transduction mechanism, but also on the molecular interaction between Suc and soluble starch.
