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Arntsen C, Guillemin J, Audette K, Stanley M. Tastant-receptor interactions: insights from the fruit fly. Front Nutr 2024; 11:1394697. [PMID: 38665300 PMCID: PMC11043608 DOI: 10.3389/fnut.2024.1394697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Accepted: 04/02/2024] [Indexed: 04/28/2024] Open
Abstract
Across species, taste provides important chemical information about potential food sources and the surrounding environment. As details about the chemicals and receptors responsible for gustation are discovered, a complex view of the taste system is emerging with significant contributions from research using the fruit fly, Drosophila melanogaster, as a model organism. In this brief review, we summarize recent advances in Drosophila gustation and their relevance to taste research more broadly. Our goal is to highlight the molecular mechanisms underlying the first step of gustatory circuits: ligand-receptor interactions in primary taste cells. After an introduction to the Drosophila taste system and how it encodes the canonical taste modalities sweet, bitter, and salty, we describe recent insights into the complex nature of carboxylic acid and amino acid detection in the context of sour and umami taste, respectively. Our analysis extends to non-canonical taste modalities including metals, fatty acids, and bacterial components, and highlights unexpected receptors and signaling pathways that have recently been identified in Drosophila taste cells. Comparing the intricate molecular and cellular underpinnings of how ligands are detected in vivo in fruit flies reveals both specific and promiscuous receptor selectivity for taste encoding. Throughout this review, we compare and contextualize these Drosophila findings with mammalian research to not only emphasize the conservation of these chemosensory systems, but to demonstrate the power of this model organism in elucidating the neurobiology of taste and feeding.
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Affiliation(s)
| | | | | | - Molly Stanley
- Department of Biology, University of Vermont, Burlington, VT, United States
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Padalhin A, Abueva C, Park SY, Ryu HS, Lee H, Kim JI, Chung PS, Woo SH. Recovery of sweet taste preference in adult rats following bilateral chorda tympani nerve transection. PeerJ 2022; 10:e14455. [PMID: 36452076 PMCID: PMC9703994 DOI: 10.7717/peerj.14455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 11/02/2022] [Indexed: 11/26/2022] Open
Abstract
Background Numerous studies have noted the effect of chorda tympani (CT) nerve transection on taste sensitivity yet very few have directly observed its effects on taste receptor and taste signaling protein expressions in the tongue tissue. Methods In this study, bilateral CT nerve transection was performed in adult Sprague Dawley rats after establishing behavioral taste preference for sweet, bitter, and salty taste via short term two-bottle preference testing using a lickometer setup. Taste preference for all animals were subsequently monitored. The behavioral testing was paired with tissue sampling and protein expression analysis. Paired groups of CT nerve transected animals (CTX) and sham operated animals (SHAM) were sacrificed 7, 14, and 28 days post operation. Results Immunofluorescence staining of extracted tongue tissues shows that CT nerve transection resulted in micro-anatomical changes akin to previous investigations. Among the three taste qualities tested, only the preference for sweet taste was drastically affected. Subsequent results of the short-term two-bottle preference test indicated recovery of sweet taste preference over the course of 28 days. This recovery could possibly be due to maintenance of T1R3, GNAT3, and TRPM5 proteins allowing adaptable recovery of sweet taste preference despite down-regulation of both T1R2 and Sonic hedgehog proteins in CTX animals. This study is the first known attempt to correlate the disruption in taste preference with the altered expression of taste receptors and taste signaling proteins in the tongue brought about by CT nerve transection.
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Affiliation(s)
- Andrew Padalhin
- Beckman Laser Institute Korea, College of Medicine, Dankook University, Cheonan, Chungcheongnam-do, Republic of Korea
| | - Celine Abueva
- Beckman Laser Institute Korea, College of Medicine, Dankook University, Cheonan, Chungcheongnam-do, Republic of Korea,Medical Laser Research Center, Dankook University, Cheonan, Chungcheongnam-do, Republic of Korea
| | - So Young Park
- Beckman Laser Institute Korea, College of Medicine, Dankook University, Cheonan, Chungcheongnam-do, Republic of Korea
| | - Hyun Seok Ryu
- Interdisciplinary Program for Medical Laser, College of Medicine, Dankook University, Cheonan, Chungcheongnam-do, Republic of Korea
| | - Hayoung Lee
- Interdisciplinary Program for Medical Laser, College of Medicine, Dankook University, Cheonan, Chungcheongnam-do, Republic of Korea
| | - Jae Il Kim
- Department of Neurology, Dankook University College of Medicine, Dankook University Hospital, Cheonan, Chungcheongnam-do, Republic of Korea
| | - Phil-Sang Chung
- Beckman Laser Institute Korea, College of Medicine, Dankook University, Cheonan, Chungcheongnam-do, Republic of Korea,Medical Laser Research Center, Dankook University, Cheonan, Chungcheongnam-do, Republic of Korea,Department of Otorhinolaryngology‐Head and Neck Surgery, Dankook University College of Medicine, Cheonan, Chungcheonam-do, Republic of Korea
| | - Seung Hoon Woo
- Beckman Laser Institute Korea, College of Medicine, Dankook University, Cheonan, Chungcheongnam-do, Republic of Korea,Medical Laser Research Center, Dankook University, Cheonan, Chungcheongnam-do, Republic of Korea,Department of Otorhinolaryngology‐Head and Neck Surgery, Dankook University College of Medicine, Cheonan, Chungcheonam-do, Republic of Korea
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3
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Schreiber A, Braymer HD, Primeaux SD. Transection of Gustatory Nerves Differentially Affects Dietary Fat Intake in Obesity-Prone and Obesity-Resistant Rats. Chem Senses 2021; 45:541-548. [PMID: 32766712 DOI: 10.1093/chemse/bjaa053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The current prevalence of obesity has been linked to the consumption of highly palatable foods and may be mediated by a dysregulated or hyposensitive orosensory perception of dietary fat, thereby contributing to the susceptibility to develop obesity. The goal of the current study was to investigate the role of lingual taste input in obesity-prone (OP, Osborne-Mendel) and obesity-resistant (OR, S5B/Pl) rats on the consumption of a high-fat diet (HFD). Density of fungiform papillae was assessed as a marker of general orosensory input. To determine if orosensory afferent input mediates dietary fat intake, surgical transection of the chorda tympani and glossopharyngeal nerves (GLX/CTX) was performed in OP and OR rats and HFD caloric intake and body weight were measured. Fungiform papillae density was lower in OP rats, compared with OR rats. GLX/CTX decreased orosensory input in both OP and OR rats, as measured by an increase in the intake of a bitter, quinine solution. Consumption of low-fat diet was not altered by GLX/CTX in OP and OR rats; however, GLX/CTX decreased HFD intake in OR, without altering HFD intake in OP rats. Overall, these data suggest that inhibition of orosensory input in OP rats do not decrease fat intake, thereby supporting that idea that hyposensitive and/or dysregulated orosensory perception of highly palatable foods contribute to the susceptibility to develop obesity.
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Affiliation(s)
- Allyson Schreiber
- Department of Physiology, LSU Health Sciences Center, New Orleans, LA, USA
| | - Hugh Douglas Braymer
- Joint Diabetes, Endocrinology & Metabolism Program, Pennington Biomedical Research Center, Baton Rouge, LA, USA
| | - Stefany D Primeaux
- Department of Physiology, LSU Health Sciences Center, New Orleans, LA, USA.,Joint Diabetes, Endocrinology & Metabolism Program, Pennington Biomedical Research Center, Baton Rouge, LA, USA
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4
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Tarragon E, Cases Ceano-Vivas P, Gonzalez-Ogazón P, Moreno JJ. Perceived Intensity and Palatability of Fatty Culinary Preparations is Associated with Individual Fatty Acid Detection Threshold and the Fatty Acid Profile of Oils Used as Ingredients. Chem Senses 2021; 46:6208271. [PMID: 33821988 DOI: 10.1093/chemse/bjab014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The term oleogustus was recently proposed to describe a sixth basic taste that could guide preference for fatty foods and dishes to an extent. However, experimental data on food preference based on fatty acid (FA) content is scarce. Our aim was to examine the role of FA profile of oils and preparations as well as FA sensory thresholds on the palatability of salty and sweet culinary preparations representative of traditional Spanish Mediterranean cooking. In this study, we used three oils with similar texture and odor profile but different in their FA composition (saturated, monounsaturated, and polyunsaturated) and compared subjects in regard to their FA detection threshold and perceived pleasantness and intensity. Our results indicate that whereas saturated FAs cannot be detected at physiological concentrations, individuals can be categorized as tasters and nontasters, according to their sensory threshold to linoleic acid, which is negatively associated with perceived intensity (r = -0.393, P < 0.001) but positively with palatability (r = 0.246, P = 0.018). These differences may be due to a possible response to a fat taste. This sixth taste, or oleogustus. would allow establishing differences in taste intensity/palatability considering the FA profile of the culinary preparations. Given that tasters can detect linoleic and oleic acid at lower concentrations than nontasters, a greater amount of unsaturated FAs in culinary preparations could provoke an unpleasant experience. This finding could be relevant in the context of the culinary sector and to further our understanding of food preference and eating behavior.
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Affiliation(s)
- Ernesto Tarragon
- Faculty of Health Sciences, Universidad Internacional de La Rioja, Logroño, Spain
| | - Pere Cases Ceano-Vivas
- Department of Nutrition, Food Sciences and Gastronomy, University of Barcelona, Barcelona, Spain
| | - Pol Gonzalez-Ogazón
- Department of Nutrition, Food Sciences and Gastronomy, University of Barcelona, Barcelona, Spain
| | - Juan José Moreno
- Department of Nutrition, Food Sciences and Gastronomy, University of Barcelona, Barcelona, Spain.,Institute of Nutrition and Food Safety, University of Barcelona, Barcelona, Spain.,CIBEROBN Fisiopatologia de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
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5
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Yasumatsu K, Iwata S, Inoue M, Ninomiya Y. Fatty acid taste quality information via GPR120 in the anterior tongue of mice. Acta Physiol (Oxf) 2019; 226:e13215. [PMID: 30375738 DOI: 10.1111/apha.13215] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 10/11/2018] [Accepted: 10/24/2018] [Indexed: 12/31/2022]
Abstract
AIM To elucidate whether fatty acid taste has a quality that does not overlap with other primary qualities, we investigated potential neuron types coding fatty acid information and how GPR120 is involved. METHODS Single fibre recordings in the chorda tympani (CT) nerve and behavioural response measurements using a conditioned taste aversion paradigm were performed in GPR120-knockout (KO) and wild-type (WT) mice. RESULTS Single fibres can be classified into fatty acid (F)-, S-, M-, electrolyte (E)-, Q-, and N-type groups according to the maximal response among oleic acid, sucrose, monopotassium glutamate (MPG), HCl, quinine hydrochloride, and NaCl respectively. Among fibres, 4.0% in GPR120-KO and 17.9% in WT mice showed a maximal response to oleic acid (F-type). Furthermore, half or more of S- and M-type fibres showed responses to fatty acids in both mouse strains, although the thresholds in KO mice were significantly higher and impulse frequencies lower than those in WT mice. GPR120-KO mice conditioned to avoid linoleic acid showed generalized stimulus avoidances for MPG, indicating qualitative similarity between linoleic acid and MPG. The KO mice showed a higher generalization threshold for linoleic acid than that of WT mice. CONCLUSION Fatty acid taste is suggested to have a unique quality owing to the discovery of F-type fibres, with GPR120 involved in neural information pathways for a unique quality and palatable taste qualities in the mouse CT nerve. GPR120 plays roles in distinguishing fatty acid taste from other primary tastes and the detection of low linoleic acid concentrations.
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Affiliation(s)
- Keiko Yasumatsu
- Division of Sensory Physiology, Research and Development Center for Taste and Odor Sensing Kyushu University Fukuoka Japan
| | - Shusuke Iwata
- Division of Sensory Physiology, Research and Development Center for Taste and Odor Sensing Kyushu University Fukuoka Japan
| | - Mayuko Inoue
- Division of Sensory Physiology, Research and Development Center for Taste and Odor Sensing Kyushu University Fukuoka Japan
| | - Yuzo Ninomiya
- Division of Sensory Physiology, Research and Development Center for Taste and Odor Sensing Kyushu University Fukuoka Japan
- Monell Chemical Senses Center Philadelphia Pennsylvania
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6
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Pittman DW, Hansen DR, Gilbertson TA. High-Fat Diet Alters the Orosensory Sensitivity to Fatty Acids in Obesity-Resistant but not Obesity-Prone Rats. J Mol Genet Med 2015; 9:168. [PMID: 26097499 PMCID: PMC4470254 DOI: 10.4172/1747-0862.1000168] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Gene-environment interactions play a role in the development of obesity but specific effects of diet on the orosensory detection of fatty acids have yet to be clarified. The objective of this study is to characterize the effect of prolonged (5-week) exposure to a high-fat (60%) diet on the behavioral sensitivity to the fatty acid linoleate following a conditioned taste aversion in obesity-prone and obesity-resistant rats. Exposure to the high-fat diet significantly enhanced the sensitivity of obesity-resistant (S5B/Pl) rats to linoleate while producing no effect on the fatty acid sensitivity for obesity-prone rats. Specifically, high-fat diet fed S5B/Pl rats showed stronger initial avoidance of linoleate and slower extinction rates than their normal diet cohorts. Our study suggests that prolonged dietary fat consumption may alter the behavioral sensitivity to fatty acids particularly in obesity-resistant animals.
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Abstract
Fat is a vital macronutrient, and its intake is closely monitored by an array of molecular sensors distributed throughout the alimentary canal. In the mouth, dietary fat constituents such as mono- and diunsaturated fatty acids give rise to taste signals that stimulate food intake, in part by enhancing the production of lipid-derived endocannabinoid messengers in the gut. As fat-containing chyme enters the small intestine, it causes the formation of anorexic lipid mediators, such as oleoylethanolamide, which promote satiety. These anatomically and functionally distinct responses may contribute to the homeostatic control and, possibly, the pathological dysregulation of food intake.
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Affiliation(s)
| | - Daniele Piomelli
- Departments of Anatomy and Neurobiology
- Department of Pharmacology, and
- Department of Biological Chemistry, School of Medicine, University of California, Irvine, Irvine, California, USA
- Drug Discovery and Development, Istituto Italiano di Tecnologia, Genoa, Italy
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8
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Massen JJM, Dusch K, Eldakar OT, Gallup AC. A thermal window for yawning in humans: yawning as a brain cooling mechanism. Physiol Behav 2014; 130:145-8. [PMID: 24721675 DOI: 10.1016/j.physbeh.2014.03.032] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 02/24/2014] [Accepted: 03/31/2014] [Indexed: 12/23/2022]
Abstract
The thermoregulatory theory of yawning posits that yawns function to cool the brain in part due to counter-current heat exchange with the deep inhalation of ambient air. Consequently, yawning should be constrained to an optimal thermal zone or range of temperature, i.e., a thermal window, in which we should expect a lower frequency at extreme temperatures. Previous research shows that yawn frequency diminishes as ambient temperatures rise and approach body temperature, but a lower bound to the thermal window has not been demonstrated. To test this, a total of 120 pedestrians were sampled for susceptibly to self-reported yawn contagion during distinct temperature ranges and seasons (winter: 1.4°C, n=60; summer: 19.4°C, n=60). As predicted, the proportion of pedestrians reporting yawning was significantly lower during winter than in summer (18.3% vs. 41.7%), with temperature being the only significant predictor of these differences across seasons. The underlying mechanism for yawning in humans, both spontaneous and contagious, appears to be involved in brain thermoregulation.
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Affiliation(s)
- Jorg J M Massen
- Department of Cognitive Biology, University of Vienna, Vienna, Austria.
| | - Kim Dusch
- Department of Education, University of Vienna, Vienna, Austria
| | - Omar Tonsi Eldakar
- Farquhar College of Arts and Sciences, Nova Southeastern University, Ft. Lauderdale, USA
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9
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DiPatrizio NV. Is fat taste ready for primetime? Physiol Behav 2014; 136:145-54. [PMID: 24631296 DOI: 10.1016/j.physbeh.2014.03.002] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 02/26/2014] [Accepted: 03/05/2014] [Indexed: 12/11/2022]
Abstract
Mounting evidence suggests that gustation is important for the orosensory detection of dietary fats, and might contribute to preferences that humans, rodents, and possibly other mammals exhibit for fat-rich foods. In contrast to sweet, sour, salty, bitter, and umami, fat is not widely recognized as a primary taste quality. Recent investigations, however, provide a wealth of information that is helping to elucidate the specific molecular, cellular, and neural mechanisms required for fat detection in mammals. The latest evidence supporting a fat taste will be explored in this review, with a particular focus on recent studies that suggest a surprising role for gut-brain endocannabinoid signaling in controlling intake and preference for fats based on their proposed taste properties.
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Affiliation(s)
- Nicholas V DiPatrizio
- Department of Anatomy and Neurobiology, University of California, Irvine, School of Medicine, United States.
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10
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Running CA, Mattes RD, Tucker RM. Fat taste in humans: Sources of within- and between-subject variability. Prog Lipid Res 2013; 52:438-45. [DOI: 10.1016/j.plipres.2013.04.007] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2013] [Revised: 04/26/2013] [Accepted: 04/27/2013] [Indexed: 01/14/2023]
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11
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DiPatrizio NV, Joslin A, Jung KM, Piomelli D. Endocannabinoid signaling in the gut mediates preference for dietary unsaturated fats. FASEB J 2013; 27:2513-20. [PMID: 23463697 DOI: 10.1096/fj.13-227587] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Dietary fat exerts a potent stimulatory effect on feeding. This effect is mediated, at least in part, by a cephalic mechanism that involves recruitment of the vagus nerve and subsequent activation of endocannabinoid signaling in the gut. Here, we used a sham-feeding protocol in rats to identify fatty-acid constituents of dietary fat that might be responsible for triggering small-intestinal endocannabinoid signaling. Sham feeding rats with a corn oil emulsion increased endocannabinoid levels in jejunum, relative to animals that received either mineral oil (which contains no fatty acids) or no oil. Sham-feeding emulsions containing oleic acid (18:1) or linoleic acid (18:2) caused, on average, a nearly 2-fold accumulation of jejunal endocannabinoids, whereas emulsions containing stearic acid (18:0) or linolenic acid (18:3) had no such effect. In a 2-bottle-choice sham-feeding test, rats displayed strong preference for emulsions containing 18:2, which was blocked by pretreatment with the peripherally restricted CB1 cannabinoid receptor antagonists, AM6546 and URB447. Our results suggest that oral exposure to the monoenoic and dienoic fatty acid component of dietary fat selectively initiates endocannabinoid mobilization in the gut, and that this local signaling event is essential for fat preference.
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Affiliation(s)
- Nicholas V DiPatrizio
- Department of Anatomy and Neurobiology, University of California-Irvine School of Medicine, Irvine, CA 92697-1275, USA
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12
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Kulkarni B, Mattes R. Evidence for Presence of Nonesterified Fatty Acids as Potential Gustatory Signaling Molecules in Humans. Chem Senses 2012; 38:119-27. [DOI: 10.1093/chemse/bjs095] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Mattes RD. Accumulating evidence supports a taste component for free fatty acids in humans. Physiol Behav 2011; 104:624-31. [PMID: 21557960 PMCID: PMC3139746 DOI: 10.1016/j.physbeh.2011.05.002] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Revised: 04/13/2011] [Accepted: 05/03/2011] [Indexed: 01/22/2023]
Abstract
The requisite criteria for what constitutes a taste primary have not been established. Recent advances in understanding of the mechanisms and functions of taste have prompted suggestions for an expanded list of unique taste sensations, including fat, or more specifically, free fatty acids (FFA). A set of criteria are proposed here and the data related to FFA are reviewed on each point. It is concluded that the data are moderate to strong that there are: A) adaptive advantages to FFA detection in the oral cavity; B) adequate concentrations of FFA to serve as taste stimuli; C) multiple complimentary putative FFA receptors on taste cells; D) signals generated by FFA that are conveyed by gustatory nerves; E) sensations generated by FFA that can be detected and scaled by psychophysical methods in humans when non-gustatory cues are masked; and F) physiological responses to oral fat/FFA exposure. On no point is there strong evidence challenging these observations. The reviewed findings are suggestive, albeit not definitive, that there is a taste component for FFA.
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Affiliation(s)
- Richard D Mattes
- Department of Foods and Nutrition, Purdue University, 700 W State Street, West Lafayette, IN 47907-2059, USA.
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14
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Galindo MM, Voigt N, Stein J, van Lengerich J, Raguse JD, Hofmann T, Meyerhof W, Behrens M. G protein-coupled receptors in human fat taste perception. Chem Senses 2011; 37:123-39. [PMID: 21868624 DOI: 10.1093/chemse/bjr069] [Citation(s) in RCA: 154] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In contrast to carbohydrates and proteins, which are detected by specialized taste receptors in the forms of their respective building blocks, sugars, and L-amino acids, the third macronutrient, lipids, has until now not been associated with gustatory receptors. Instead, the recognition of fat stimuli was believed to rely mostly on textural, olfactory, and postingestive cues. During the recent years, however, research done mainly in rodent models revealed an additional gustatory component for the detection of long-chain fatty acids (LCFAs), the main taste-activating component of lipids. Concomitantly, a number of candidate fat taste receptors were proposed to be involved in rodent's gustatory fatty acid perception. Compared with rodent models, much less is known about human fat taste. In order to investigate the ability of the human gustatory system to respond to fat components, we performed sensory experiments with fatty acids of different chain lengths and derivatives thereof. We found that our panelists discriminated a "fatty" and an irritant "scratchy" taste component, with the "fatty" percept restricted to LCFAs. Using functional calcium-imaging experiments with the human orthologs of mouse candidate fat receptors belonging to the G protein-coupled receptor family, we correlated human sensory data with receptor properties characterized in vitro. We demonstrated that the pharmacological activation profile of human GPR40 and GPR120, 2 LCFA-specific receptors associated with gustatory fat perception in rodents, is inconsistent with the "scratchy" sensation of human subjects and more consistent with the percept described as "fatty." Expression analysis of GPR40 and GPR120 in human gustatory tissues revealed that, while the GPR40 gene is not expressed, GPR120 is detected in gustatory and nongustatory epithelia. On a cellular level, we found GPR120 mRNA and protein in taste buds as well as in the surrounding epithelial cells. We conclude that GPR120 may indeed participate in human gustatory fatty acid perception.
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Affiliation(s)
- Maria Mercedes Galindo
- Department of Molecular Genetics, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany
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15
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Liang NC, Freet CS, Grigson PS, Norgren R. Pontine and thalamic influences on fluid rewards: I. Operant responding for sucrose and corn oil. Physiol Behav 2011; 105:576-88. [PMID: 21703290 DOI: 10.1016/j.physbeh.2011.06.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Accepted: 06/11/2011] [Indexed: 10/18/2022]
Abstract
The reward strength of orosensory sucrose and corn oil was measured using fixed and progressive ratio operant schedules. Because the orosensory effects of the stimuli were of interest, Experiment 1 compared operant responses for sucrose in sham and real feeding rats. The results demonstrated that rats would work for sucrose solutions without the accompanying postingestive effects. Furthermore, the break points for high concentrations of sucrose (1.0 M or 2.0 M) were significantly higher in sham feeding rats than in real feeding controls. Experiment 2 investigated the role of the parabrachial nucleus (PBN) and of the thalamic orosensory area (TOA) in sucrose and corn oil reward. During free access, rats with PBN lesions (PBNx) licked significantly less sucrose solution than their controls, but both groups ingested a similar volume of corn oil emulsion. When an operant was imposed, these same PBNx rats failed to respond for sucrose and continued only modestly for corn oil. In contrast, the TOA lesioned rats (TOAx) showed no impairment in responding for sucrose or corn oil during either the free access or operant sessions. Furthermore, rats with TOA lesions demonstrated significantly higher break points for sucrose than did their controls. Together, the data imply that the PBN but not the TOA is critical for the perception of, or responding to the reward value of sucrose and corn oil.
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Affiliation(s)
- Nu-Chu Liang
- Department of Neural and Behavioral Sciences, College of Medicine, The Pennsylvania State University, Hershey, PA 17033, USA.
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Jauregui RC, Mattes RD, Parks EJ. Dynamics of fat absorption and effect of sham feeding on postprandial lipema. Gastroenterology 2010; 139:1538-48. [PMID: 20493191 PMCID: PMC2948783 DOI: 10.1053/j.gastro.2010.05.002] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2009] [Revised: 04/22/2010] [Accepted: 05/13/2010] [Indexed: 12/02/2022]
Abstract
BACKGROUND & AIMS Given the importance of postprandial hyperlipidemia to increase risk for atherosclerosis, in the present study, stable isotope-labeled meals were fed to healthy subjects (7 males and 3 females) to investigate the kinetics chylomicron synthesis and the effect of sensory exposure to lipid on metabolism. METHODS Subjects performed two, 24-hour inpatient studies that entailed consumption of a liquid formula evening meal containing 30 g of oil (+ (13)C(2) triolein) on day 1. Breakfast (day 2) consisted of triacylglycerols (TAGs) fed as capsules (30 g oil + (13)C(7) triolein) to avoid activation of mouth taste receptors. Next, modified sham feeding of cream cheese occurred over 2 hours. In the 2 trials, the stimulus was either higher fat (HF) or lower fat (LF) cream cheese. A liquid meal was consumed at lunch. Blood sampling occurred intermittently, and chylomicron particles S(f) >400 TAGs were analyzed by gas chromatography-mass spectrometry. RESULTS (13)C(2)-Label was found in fasting-state lipoproteins, and persons with higher body fat percentages showed greater dilution of meal TAGs from endogenous sources. For both trials, 13% ± 4% of lipoprotein TAGs oleic acid was derived from the previous evening meal. Incremental area under the curve for TAGs during HF was ∼2.5 times higher than after LF exposure (46 ± 15 vs 17 ± 5 μmol/L/h; P = .04). The greater HF morning lipemia occurred with elevated glucose, insulin, and nonesterified fatty acids peak after lunch. CONCLUSIONS These data support a connection between enteral lipid metabolism and oral fat exposure, resulting in elevated postprandial lipemia. The results suggest that the intestine may participate in a mechanism coordinating oral fat signaling with control of subsequent macronutrient disposal in the body.
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Affiliation(s)
- Rosa Chavez Jauregui
- Center for Human Nutrition, UTSW Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-9052
| | - Richard D. Mattes
- Department of Foods and Nutrition, Purdue University, 212 Stone Hall, 700 W State Street, West Lafayette, IN 47907-2059
| | - Elizabeth J. Parks
- Center for Human Nutrition, UTSW Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-9052
,To whom correspondence should be addressed: Center for Human Nutrition University of Texas Southwestern Medical Center 5323 Harry Hines Blvd., Dallas TX 75390-9052 Phone: (214) 648-2054 Fax: (214) 648-2269
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Treesukosol Y, Blonde GD, Jiang E, Gonzalez D, Smith JC, Spector AC. Necessity of the glossopharyngeal nerve in the maintenance of normal intake and ingestive bout size of corn oil by rats. Am J Physiol Regul Integr Comp Physiol 2010; 299:R1050-8. [PMID: 20668233 DOI: 10.1152/ajpregu.00763.2009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recent evidence in the literature suggests that signals carried by the glossopharyngeal nerve (GL), which supplies sensory and parasympathetic innervation of the posterior tongue, might be essential in the maintenance of normal gustatory responses to fat stimuli. Here, we report that GL transection (GLX) significantly decreased corn oil intake and preference in 23-h two-bottle tests relative to sham-operated controls (Sham). Drinking-pattern analysis of corn oil licking revealed that bout size, rather than the number of bouts initiated, was smaller in GLX than Sham rats. We also tested a range of glucose concentrations and found that total licks over daily 23-h sessions significantly decreased in GLX compared with Sham rats, but this difference failed to reach significance when intake or any bout parameter was measured. These results show that the signals in the GL normally contribute to processes involved with corn oil bout termination as opposed to bout initiation. GL-derived signals could potentially provide input to "reward" circuits in the ventral forebrain that could serve to maintain ingestion during a meal or, alternatively, could act at the level of the brain stem to attenuate the inhibitory potency of vagal signals, thus delaying the onset of satiation, or perhaps contribute to a cephalic phase reflex modulation of the gut. Parasympathetic efferents in the GL innervating the von Ebner's glands, which secrete lingual lipase, which is thought to break down corn oil into detectable ligands, could also be playing a role in driving corn oil intake. Whatever the mechanism, an intact GL is clearly necessary in maintaining normal intake of corn oil.
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Affiliation(s)
- Yada Treesukosol
- Dept. of Psychology, Florida State Univ., Tallahassee, 32306-4301, USA
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Abstract
The oral perception of fat has traditionally been considered to rely mainly on texture and olfaction, but recent findings suggest that taste may also play a role in the detection of long chain fatty acids. The two G-protein coupled receptors GPR40 (Ffar1) and GPR120 are activated by medium and long chain fatty acids. Here we show that GPR120 and GPR40 are expressed in the taste buds, mainly in type II and type I cells, respectively. Compared with wild-type mice, male and female GPR120 knock-out and GPR40 knock-out mice show a diminished preference for linoleic acid and oleic acid, and diminished taste nerve responses to several fatty acids. These results show that GPR40 and GPR120 mediate the taste of fatty acids.
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Abstract
The oral perception of fat has traditionally been considered to rely mainly on texture and olfaction, but recent findings suggest that taste may also play a role in the detection of long chain fatty acids. The two G-protein coupled receptors GPR40 (Ffar1) and GPR120 are activated by medium and long chain fatty acids. Here we show that GPR120 and GPR40 are expressed in the taste buds, mainly in type II and type I cells, respectively. Compared with wild-type mice, male and female GPR120 knock-out and GPR40 knock-out mice show a diminished preference for linoleic acid and oleic acid, and diminished taste nerve responses to several fatty acids. These results show that GPR40 and GPR120 mediate the taste of fatty acids.
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Abstract
Taste is a chemical sense that aids in the detection of nutrients and guides food choice. A limited number of primary qualities comprise taste. Accumulating evidence has raised a question about whether fat should be among them. Most evidence indicates triacylglycerol is not an effective taste stimulus, though it clearly contributes sensory properties to foods by carrying flavor compounds and altering texture. However, there is increasing anatomical, electrophysiological, animal behavior, imaging, metabolic, and psychophysical evidence that free fatty acids are detectable when non-taste cues are minimized. Free fatty acids varying in saturation and chain length are detectable, suggesting the presence of multiple transduction mechanisms and/or a nonspecific mechanism in the oral cavity. However, confirmation of "fatty" as a taste primary will require additional studies that verify these observations are taste specific. Oral exposure to free fatty acids likely serves as a warning signal to discourage intake and influences lipid metabolism.
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Stratford JM, Contreras RJ. Saliva and other taste stimuli are important for gustatory processing of linoleic acid. Am J Physiol Regul Integr Comp Physiol 2009; 297:R1162-70. [PMID: 19692663 DOI: 10.1152/ajpregu.00217.2009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Paradoxically, bilateral transection of the chorda tympani nerve (CTX) raises the taste discrimination threshold for the free fatty acid, linoleic acid (LA), yet the chorda tympani nerve (CT) is unresponsive to lingual application of LA alone. LA may require a background of saliva to activate taste cells, since CTX decreases saliva production through denervation of the submaxillary and sublingual salivary glands. To assess the role of saliva, we measured LA taste discrimination thresholds for animals whose submaxillary and sublingual salivary glands were removed and also recorded CT responses to LA mixed in artificial saliva. Partial desalivation shifted LA discrimination thresholds from between 5.5 and 11 microM to between 11 and 22 microM. However, this effect was not as pronounced as previously seen with CTX animals. Surprisingly, the CT was unresponsive to LA mixed with artificial saliva, suggesting that artificial saliva may lack components necessary for LA taste. Additionally, fats may primarily enhance other tastes. We previously reported that LA increases CT responses to monosodium glutamate (MSG). Thus we also recorded CT whole nerve responses to taste mixtures of LA and sodium chloride (NaCl), sucrose (SUC), citric acid (CA), or quinine hydrochloride (QHCl) in anesthetized rats. We found that LA increased CT responses to NaCl but did not alter CT responses to SUC, CA, and QHCl. Thus CT recordings either lack the sensitivity to detect small changes to SUC, CA, and QHCl or LA may affect CT responses to MSG and NaCl only, perhaps by specifically modulating gustatory processing of Na(+).
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Affiliation(s)
- Jennifer M Stratford
- Department of Psychology and Program in Neuroscience, The Florida State University, Tallahassee, Florida 32306-4301, USA
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Spector AC, Glendinning JI. Linking peripheral taste processes to behavior. Curr Opin Neurobiol 2009; 19:370-7. [PMID: 19674892 DOI: 10.1016/j.conb.2009.07.014] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2009] [Revised: 07/09/2009] [Accepted: 07/13/2009] [Indexed: 10/20/2022]
Abstract
The act of eating and drinking brings food-related chemicals into contact with taste cells. Activation of these taste cells, in turn, engages neural circuits in the central nervous system that help animals identify foods and fluids, determine what and how much to eat, and prepare the body for digestion and assimilation. Analytically speaking, these neural processes can be divided into at least three categories: stimulus identification, ingestive motivation, and digestive preparation. This review will discuss recent advances in peripheral gustatory mechanisms, primarily from rodent models, in the context of these three major categories of taste function.
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Affiliation(s)
- Alan C Spector
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306, USA.
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Contribution of gustation to the palatability of linoleic acid. Physiol Behav 2009; 96:142-8. [DOI: 10.1016/j.physbeh.2008.09.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2008] [Revised: 09/10/2008] [Accepted: 09/11/2008] [Indexed: 11/19/2022]
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Passilly-Degrace P, Gaillard D, Besnard P. Orosensory perception of dietary lipids in mammals. Results Probl Cell Differ 2009; 47:221-38. [PMID: 19083126 DOI: 10.1007/400_2008_7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
Abstract
Obesity constitutes a major public health problem for the twenty-first century, with its epidemic spread worldwide, particularly in children. The overconsumption of fatty foods greatly contributes to this phenomenon. Rodents and humans display a spontaneous preference for lipid-rich foods. However, the molecular mechanisms underlying this pattern of eating behaviour in mammals remain unclear. The orosensory perception of dietary lipids was long thought to involve only textural and olfactory cues. Recent findings challenge this limited viewpoint, strongly suggesting that the sense of taste also plays a significant role in dietary lipid perception and might therefore be involved in the preference for fatty foods and obesity. This minireview analyses recent data relating to the molecular mechanisms and physiological consequences of this means of orosensory lipid perception.
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Affiliation(s)
- P Passilly-Degrace
- Physiologie de la Nutrition, UMR INSERM U 866, Ecole Nationale Supérieure de Biologie Appliquée à la Nutrition et à lAlimentation, Université de Bourgogne 1, Esplanade Erasme, 21000 Dijon, France
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Gaillard D, Passilly-Degrace P, Besnard P. Molecular mechanisms of fat preference and overeating. Ann N Y Acad Sci 2008; 1141:163-75. [PMID: 18991957 DOI: 10.1196/annals.1441.028] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Obesity is recognized as a worldwide health problem. Overconsumption of fatty foods contributes significantly to this phenomenon. Rodents, like humans, display preferences for lipid-rich foods. Rodents thus provide useful models to explore the mechanisms responsible for this complex feeding behavior resulting from the integration of multiple oral and postoral signals. Over the last decades, the lipid-mediated regulation of food intake has received considerable attention. By contrast, orosensory lipid perception was long thought to involve only textural and olfactory cues. Recent findings have challenged this limited viewpoint. These recent data strongly suggest that the sense of taste also plays significant roles in the spontaneous preference for fatty foods. This paper provides a brief overview of postoral regulation of food intake by lipids and then highlights recent data suggesting the existence of a "fatty taste" which might contribute to lipid overeating and hence to the risk of obesity.
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Affiliation(s)
- Dany Gaillard
- Physiologie de la Nutrition, UMR INSERM U866, Ecole Nationale Supérieure de Biologie Appliquée à la Nutrition et à l'Alimentation (ENSBANA), Université de Bourgogne, Dijon, France
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Stratford JM, Curtis KS, Contreras RJ. Linoleic acid increases chorda tympani nerve responses to and behavioral preferences for monosodium glutamate by male and female rats. Am J Physiol Regul Integr Comp Physiol 2008; 295:R764-72. [PMID: 18635450 DOI: 10.1152/ajpregu.00916.2007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previous studies suggest that the chorda tympani nerve (CT) is important in transmitting fat taste information to the central nervous system. However, the contribution of the CT in this process may depend upon the presence of other taste stimuli and/or differ in males and females. Accordingly, the present study investigated the role of the CT in free fatty acid taste processing by examining electrophysiological activity of the CT in response to the free fatty acid linoleic acid (LA), as well as by measuring behavioral responses to LA-taste mixtures. We recorded whole nerve responses from the CT in response to lingual application of LA with or without monosodium glutamate (MSG) in anesthetized male and female rats. In addition, we examined preferences for MSG + LA taste mixtures in behavioral tests. Although lingual application of LA alone did not produce CT whole nerve responses, coapplication of LA and MSG elicited greater CT responses than did MSG alone. These findings were paralleled by greater preferences for MSG + LA taste mixtures than for MSG alone. In both cases, the effect was particularly pronounced in male rats. Thus LA enhances CT activity and behavioral responses to LA + MSG taste mixtures, although there are sex differences in the effects. These results suggest that CT input is important in mediating behavioral responses to fat taste, but the effects depend upon other taste stimuli and differ in males and females.
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Affiliation(s)
- Jennifer M Stratford
- Dept. of Psychology and Program in Neuroscience, The Florida State Univ., Tallahassee, FL 32306-1270, USA
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Gaillard D, Laugerette F, Darcel N, El‐Yassimi A, Passilly‐Degrace P, Hichami A, Khan NA, Montmayeur J, Besnard P. The gustatory pathway is involved in CD36‐mediated orosensory perception of long‐chain fatty acids in the mouse. FASEB J 2007; 22:1458-68. [DOI: 10.1096/fj.07-8415com] [Citation(s) in RCA: 180] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Dany Gaillard
- Physiologie de la Nutrition, UMR INSERM U 866, Ecole Nationale Supérieure de Biologie Appliquée à la Nutrition et à l'AlimentationUniversité de Bourgogne DijonFrance
| | - Fabienne Laugerette
- Physiologie de la Nutrition, UMR INSERM U 866, Ecole Nationale Supérieure de Biologie Appliquée à la Nutrition et à l'AlimentationUniversité de Bourgogne DijonFrance
- Chimioréception, Centre Européen des Sciences du Goût, UMR 5170 Centre National de la Recherche Scientifique/1214 Institut National de la Recherche Agronomique (INRA)/Université de BourgogneDijonFrance
| | - Nicolas Darcel
- Physiologie de la Nutrition et du Comportement AlimentaireInstitut National Agronomique Paris Grignon (INAPG), UMR 914 INRA/INAPGParisFrance
| | - Abdelghani El‐Yassimi
- Unité Propre de Recherche de l'Enseignement Supérieur (UPRES) 4183 Lipides et Signalisation CellulaireUniversité de BourgogneDijonFrance
| | - Patricia Passilly‐Degrace
- Physiologie de la Nutrition, UMR INSERM U 866, Ecole Nationale Supérieure de Biologie Appliquée à la Nutrition et à l'AlimentationUniversité de Bourgogne DijonFrance
| | - Aziz Hichami
- Unité Propre de Recherche de l'Enseignement Supérieur (UPRES) 4183 Lipides et Signalisation CellulaireUniversité de BourgogneDijonFrance
| | - Naim Akhtar Khan
- Unité Propre de Recherche de l'Enseignement Supérieur (UPRES) 4183 Lipides et Signalisation CellulaireUniversité de BourgogneDijonFrance
| | - Jean‐Pierre Montmayeur
- Chimioréception, Centre Européen des Sciences du Goût, UMR 5170 Centre National de la Recherche Scientifique/1214 Institut National de la Recherche Agronomique (INRA)/Université de BourgogneDijonFrance
| | - Philippe Besnard
- Physiologie de la Nutrition, UMR INSERM U 866, Ecole Nationale Supérieure de Biologie Appliquée à la Nutrition et à l'AlimentationUniversité de Bourgogne DijonFrance
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Sclafani A, Ackroff K, Abumrad NA. CD36 gene deletion reduces fat preference and intake but not post-oral fat conditioning in mice. Am J Physiol Regul Integr Comp Physiol 2007; 293:R1823-32. [PMID: 17804586 DOI: 10.1152/ajpregu.00211.2007] [Citation(s) in RCA: 138] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Several findings suggest the existence of a “fatty” taste, and the CD36 fatty acid translocase is a candidate taste receptor. The present study compared fat preference and acceptance in CD36 knockout (KO) and wild-type (WT) mice using nutritive (triglyceride and fatty acid) and nonnutritive (Sefa Soyate oil) emulsions. In two-bottle tests (24 h/day) naive KO mice, unlike WT mice, displayed little or no preference for dilute soybean oil, linoleic acid, or Sefa Soyate emulsions. At high concentrations (2.5–20%), KO mice developed significant soybean oil preferences, although they consumed less oil than WT mice. The postoral actions of fat likely conditioned these preferences. KO mice, like WT mice, learned to prefer a flavored solution paired with intragastric soybean oil infusions. These findings support CD36 mediation of a gustatory component to fat preference but demonstrate that it is not essential for fat-conditioned flavor preferences. The finding that oil-naive KO mice failed to prefer a nonnutritive oil, assumed to provide texture rather than taste cues, requires explanation. Finally, CD36 deletion decreased fat consumption and enhanced the ability of the mice to compensate for the calories provided by their optional fat intake.
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Affiliation(s)
- A Sclafani
- Dept. of Psychology, Brooklyn College of City University of New York, Brooklyn, NY 11210, USA.
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Aly R, Maibach HI, Bagatell FK, Dittmar W, Hänel H, Falanga V, Leyden JJ, Roth HL, Stoughton RB, Willis I. Ciclopirox olamine lotion 1%: bioequivalence to ciclopirox olamine cream 1% and clinical efficacy in tinea pedis. Clin Ther 1989; 96:151-76. [PMID: 2663159 DOI: 10.1152/physrev.00002.2015] [Citation(s) in RCA: 140] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Studies were conducted to assess the bioequivalence of a new antimycotic formulation, ciclopirox olamine lotion 1%, to an established compound, ciclopirox olamine cream 1%. Results of in vitro studies, using skin samples from human cadavers and domestic pigs, demonstrated that the two formulations equally penetrate all layers of the stratum corneum and inhibit the growth of Trichophyton mentagrophytes and Candida albicans. In vivo studies in guinea pigs and in human volunteers demonstrated the comparable therapeutic efficacy of the lotion and the cream in experimental trichophytosis. In addition, a multicenter, double-blind clinical trial was undertaken to compare ciclopirox olamine lotion 1% with the vehicle alone in the treatment of patients with tinea pedis. Patients with plantar, interdigital, or vesicular tinea pedis were enrolled in the studies. Patients were treated for 28 days. Clinical and mycological responses were determined during treatment and two weeks posttreatment. Ciclopirox olamine lotion 1% was found to be significantly more effective than its vehicle in the treatment of patients with common tinea pedis. Minor localized side effects (pruritus, burning sensation) were reported in 2% of 89 patients treated with ciclopirox olamine lotion 1%. The results demonstrate the bioequivalence of ciclopirox olamine lotion 1% and ciclopirox olamine cream 1% and confirm the clinical effectiveness and safety of the lotion in the treatment of tinea pedis, a generally recalcitrant fungal infection. It is concluded that ciclopirox olamine lotion 1% can be used as an alternative to ciclopirox olamine cream 1% for treatment of tinea pedis, tinea versicolor, tinea cruris, tinea corporis, and cutaneous candidiasis when the convenience and/or cosmetic elegance of a lotion is desired.
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Affiliation(s)
- R Aly
- Department of Dermatology, University of California School of Medicine, San Francisco
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