title: High intake of dietary tyramine does not deteriorate glucose handling and does not cause adverse cardiovascular effects in mice.
abstract: Tyramine is naturally occurring in food and induces pressor responses. Low-tyramine diets are recommended for patients treated with MAO inhibitors to avoid the fatal hypertensive crisis sadly known as "cheese effect". Hence, tyramine intake is suspected to have toxicological consequences in humans, while its administration to type 1 diabetic rodents has been reported to improve glucose tolerance. We investigated in mice whether prolonged tyramine ingestion could alter glucose homeostasis, insulin sensitivity, adipose tissue physiology or cardiovascular functions. Tyramine was added at 0.04 or 0.14 % in the drinking water since this was estimated to increase by 10- to 40-fold the spontaneous tyramine intake of control mice fed a standard diet. Ten to 12 weeks of such tyramine supplementation did not influence body weight gain, adiposity or food consumption. Both doses (reaching approx. 300 and 1100 μmol tyramine/kg bw/day) decreased nonfasting blood glucose but did not modify glucose tolerance or fasting levels of glucose, insulin or circulating lipids. Blood pressure was not increased in tyramine-drinking mice, while only the higher tested dose moderately increased heart rate without change in its variability. Markers of cardiac tissue injury or oxidative stress remained unaltered, except an increased hydrogen peroxide production in heart preparations. In isolated adipocytes, tyramine inhibited lipolysis similarly in treated and control groups, as did insulin. The lack of serious adverse cardiovascular effects of prolonged tyramine supplementation in normoglycemic mice together with the somewhat insulin-like effects found on adipose cells should lead to reconsider favourably the risk/benefit ratio of the intake of this dietary amine.
authors.affiliation: Institut des Maladies Métaboliques et Cardiovasculaires, Institut National de la Santé et de la Recherche Médicale (INSERM U1048) and Université Paul Sabatier (I2MC-UPS), 31432, Toulouse, Cedex 4, France. christian.carpene@inserm.fr.
authors.forename: Christian
authors.initials: C
authors.lastname: Carpéné
authors.affiliation: Institut des Maladies Métaboliques et Cardiovasculaires, Institut National de la Santé et de la Recherche Médicale (INSERM U1048) and Université Paul Sabatier (I2MC-UPS), 31432, Toulouse, Cedex 4, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Schaak
authors.affiliation: Institut des Maladies Métaboliques et Cardiovasculaires, Institut National de la Santé et de la Recherche Médicale (INSERM U1048) and Université Paul Sabatier (I2MC-UPS), 31432, Toulouse, Cedex 4, France.
authors.forename: Céline
authors.initials: C
authors.lastname: Guilbeau-Frugier
authors.affiliation: Alimentómica, S.L, Empresa de Base Tecnológica de la Universitat de les Illes Balears, Palma de Mallorca, Spain.
authors.forename: Josep
authors.initials: J
authors.lastname: Mercader
authors.affiliation: Institut des Maladies Métaboliques et Cardiovasculaires, Institut National de la Santé et de la Recherche Médicale (INSERM U1048) and Université Paul Sabatier (I2MC-UPS), 31432, Toulouse, Cedex 4, France.
authors.forename: Jeanne
authors.initials: J
authors.lastname: Mialet-Perez
mesh_terms: D017667:Adipocytes / Q000166:cytology / Q000378:metabolism / Q000473:pathology; D050154:Adiposity; D000818:Animals; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000032:analysis; D002318:Cardiovascular Diseases / Q000097:blood / Q000209:etiology* / Q000378:metabolism / Q000473:pathology; D002478:Cells, Cultured; D004032:Diet / Q000009:adverse effects*; D002149:Energy Intake; D018149:Glucose Intolerance / Q000097:blood / Q000209:etiology* / Q000378:metabolism / Q000473:pathology; D006861:Hydrogen Peroxide / Q000819:agonists / Q000378:metabolism; D007328:Insulin / Q000032:analysis; D008055:Lipids / Q000097:blood; D008297:Male; D008810:Mice, Inbred C57BL; D009206:Myocardium / Q000378:metabolism; D018384:Oxidative Stress; D013997:Time Factors; D036401:Toxicity Tests, Chronic; D014439:Tyramine / Q000008:administration & dosage / Q000009:adverse effects*; D014662:Vasoconstrictor Agents / Q000008:administration & dosage / Q000009:adverse effects*; D015430:Weight Gain
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D007328:Insulin; D008055:Lipids; D014662:Vasoconstrictor Agents; D006861:Hydrogen Peroxide; D014439:Tyramine
keywords: Adipocyte; Fat deposition; Glucose homeostasis; Heart rate variability; Monoamine oxidase