Previous studies from this laboratory demonstrate that dietary leucine protects against high fat diet-induced mitochondrial impairments and stimulates mitochondrial biogenesis and energy partitioning from adipocytes to muscle cells through SIRT1-mediated mechanisms. Moreover, β-hydroxy-β-methyl butyrate (HMB), a metabolite of leucine, has been reported to activate AMPK synergistically with resv...

Physiological conditions in humans affect plasma amino acid profiles that might have potential for medical use. Because the branched-chain amino acids (BCAAs) leucine, isoleucine and valine are used as medicines and supplements, we investigated the acute effects of individual BCAAs (10-90 mg/kg body weight) or mixed BCAAs ingested as a bolus on plasma amino acid profiles in young healthy men. P...

In separate experiments the isoleucine and leucine requirements of the kitten were determined on the basis of growth and nitrogen retention. The dietary concentrations of isoleucine tested were (g/kg diet) 1.4, 2.2, 3.0, 3.8, 4.6 and 9.0 with adequate (12.0 g/kg diet) leucine. The levels of leucine tested were (g/kg diet) 5.0, 7.5, 9.0, 10.5, 12.0 and 20.0 in diets containing adequate (9.0 g/kg...

BACKGROUND It is poorly understood how hyperpolarization-activated cyclic nucleotide-gated channels (HCNs) function. RESULTS We have identified a leucine zipper in the S5 segment of HCNs, regulating hyperpolarization-activated and instantaneous current components. CONCLUSION The leucine zipper is essential for HCN channel gating. SIGNIFICANCE The identification and functional characteriza...

The branched-chain amino acids are transported into the bacteria Escherichia coli by two types of transport systems, a high affinity transport system (LIV-I) which requires periplasmic binding proteins and a low affinity membrane bound system (LIV-11). The LIV-I system is sensitive to osmotic shock while the LIV-I1 system can be observed in membrane vesicle preparations (Kaback, ’71). Berger an...

The present study examined the functional characteristics of the inward and outward L-[14C]DOPA and L-[14C]leucine transporters in LLC-PK1 cells. Uptake was initiated by the addition of Hanks' medium with a given concentration of L-[14C]DOPA or L-[14C]leucine. Saturation experiments were performed in cells incubated for 6 min with 0.25 microM concentration of the substrates in the absence and t...

BACKGROUND Leucine supplementation has been reported to improve lipid metabolism. However, lipid metabolism in adipose tissues and liver has not been extensively studied for leucine supplementation in mice fed with a high-fat/cholesterol diet (HFCD). DESIGN C57BL/6J mice were fed a chow diet, HFCD, HFCD supplemented with 1.5% leucine (HFCD+1.5% Leu group) or 3% leucine (HFCD+3% Leu group) for...

Leucine and monomethyl succinate initiate insulin release, and glutamine potentiates leucine-induced insulin release. Alanine enhances and malate inhibits leucine plus glutamine-induced insulin release. The insulinotropic effect of leucine is at least in part secondary to its ability to activate glutamate oxidation by glutamate dehydrogenase (Sener, A., Malaisse-Lagae, F., and Malaisse, W. J. (...

The anabolic actions of GH in GH-deficient adults and children are well documented. Replacement with GH in such individuals promotes protein synthesis and reduces irreversible loss of protein through oxidation. Although GH is known to be self-administered by athletes, its protein metabolic effects in this context are unknown. This study was designed to determine whether 4 wk of high dose recomb...

PURPOSE This study was performed to explore the physiological functions of leucine by exploring genes with leucine-dependent variability using DNA microarray. METHODS Sprague-Dawley rats (n = 20) were separated into a HPD (30% High Protein Diet, n = 10) group and a NPD (0% Non Protein Diet, n = 10) group and fed a protein diet for 2 weeks. At the end of the 2-week period, the rats were fasted...