title: Impact of taurine depletion on glucose control and insulin secretion in mice.
abstract: Taurine, an endogenous sulfur-containing amino acid, is found in millimolar concentrations in mammalian tissue, and its tissue content is altered by diet, disease and aging. The effectiveness of taurine administration against obesity and its related diseases, including type 2 diabetes, has been well documented. However, the impact of taurine depletion on glucose metabolism and fat deposition has not been elucidated. In this study, we investigated the effect of taurine depletion (in the taurine transporter (TauT) knockout mouse model) on blood glucose control and high fat diet-induced obesity. TauT-knockout (TauTKO) mice exhibited lower body weight and abdominal fat mass when maintained on normal chow than wild-type (WT) mice. Blood glucose disposal after an intraperitoneal glucose injection was faster in TauTKO mice than in WT mice despite lower serum insulin levels. Islet beta-cells (insulin positive area) were also decreased in TauTKO mice compared to WT mice. Meanwhile, overnutrition by high fat (60% fat)-diet could lead to obesity in TauTKO mice despite lower body weight under normal chow diet condition, indicating nutrition in normal diet is not enough for TauTKO mice to maintain body weight comparable to WT mice. In conclusion, taurine depletion causes enhanced glucose disposal despite lowering insulin levels and lower body weight, implying deterioration in tissue energy metabolism.
authors.affiliation: Hyogo University of Health Sciences, 1-3-6 Minatojima, Chuo-ku, Kobe, Hyogo, Japan. Electronic address: tito@huhs.ac.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Ito
authors.affiliation: Hyogo University of Health Sciences, 1-3-6 Minatojima, Chuo-ku, Kobe, Hyogo, Japan.
authors.forename: Natsumi
authors.initials: N
authors.lastname: Yoshikawa
authors.affiliation: Hyogo University of Health Sciences, 1-3-6 Minatojima, Chuo-ku, Kobe, Hyogo, Japan.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Ito
authors.affiliation: College of Medicine, University of South Alabama, 307 University Blvd. N, Mobile, AL 36688, USA.
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Schaffer
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000378:metabolism*; D001835:Body Weight; D059305:Diet, High-Fat / Q000009:adverse effects; D004195:Disease Models, Animal; D004734:Energy Metabolism / Q000187:drug effects; D055786:Gene Knockout Techniques; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009765:Obesity / Q000209:etiology / Q000378:metabolism*; D013654:Taurine / Q000172:deficiency* / Q000502:physiology*
chemical_list: D001786:Blood Glucose; D007328:Insulin; D013654:Taurine
keywords: Insulin; Obesity; TauT-knockout mouse; Taurine