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.