Effect of a Thyroid Hormone Treatment on Brain Protein Synthesis in Rats

Hayase, Kazutoshi; Naganuma, Yaeko; Moriyama, Michie; Yoshida, Akira; Yokogoshi, Hidehiko

doi:10.1271/bbb.61.1536

Cited by 10 publications

(5 citation statements)

References 9 publications

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“…However, when rats are hypophysectomized, the secretion of thyroid stimulated hormone from the pituitary gland may decrease. The thyroid hormone stimulates protein synthesis in the liver, muscle and brain regions (17). However, limited information is available on the role of thyroid hormone on the rate of protein synthesis in the brain of rats given ornithine.…”

Section: Discussionmentioning

confidence: 99%

“…However, a positive correlation between the rate of protein synthesis and RNA activity was found in the brain of aged rats when dietary protein and amino acids were manipulated (29,30). Hormonal treatments such as GH and thyroid hormone also elevated the rate of protein synthesis and RNA activity in the brain (12,17). Within the control and PTU-treated groups, RNA activity in the brain regions, rather than RNA concentration, was higher in rats fed the 20% casein 1 ornithine diet than rats fed the 20% casein diet alone (Table 3).…”

Section: Discussionmentioning

confidence: 99%

“…The thyroid hormone is essential for normal growth in the brain (16). In the previous study, we (17) demonstrated that the thyroid hormone increased the rate of protein synthesis in the rat brain. However, the role of dietary ornithine in maintaining thyroid hormone status in adult rats is unknown.…”

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confidence: 86%

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Changes in Thyroid Hormone Are Not Involved in Regulating Brain Protein Synthesis in Adults Rats Fed Ornithine

Tujioka

Yamada

Yokogoshi

et al. 2017

J Nutr Sci Vitaminol

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SummaryBrain protein synthesis and the plasma concentration of growth hormone (GH) are sensitive to dietary ornithine. However, dietary ornithine does not increase brain protein synthesis in hypophysectomized rats. Because hypophysectomy may decrease the secretion of thyroid stimulated hormone (TSH), we assessed whether the regulation of brain protein synthesis was mediated by changes in the plasma concentrations of thyroid hormone and ghrelin in the 6-propyl-2-thiouracil (PTU, thyroid inhibitor)-treated or control adult rats fed ornithine. The four experimental groups consisted of PTU-treated and control (24-wk-old) male rats given 0% or 0.7% ornithine-HCl added to a 20% casein diet. The plasma concentrations of GH and ghrelin, and the fractional rates of protein synthesis and RNA activity [g protein synthesized/(g RNA·d)] in the brains were significantly increased after treatment with the 20% casein 1 0.7% ornithine compared with the 20% casein diet alone in both the PTU-treated and control groups. Ornithine supplementation to the basal diet did not affect the plasma concentration of T3. The RNA concentration (mg RNA/g protein) was not related to the fractional rate of protein synthesis in the brain regions. The results suggest that dietary ornithine likely increases the rate of brain protein synthesis in control and PTU-treated rats, and that the ornithine-induced increase in the GH concentration may stimulate mainly brain protein synthesis via ghrelin. RNA activity is at least partly related to the fractional rate of brain protein synthesis.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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Changes in Thyroid Hormone Are Not Involved in Regulating Brain Protein Synthesis in Adults Rats Fed Ornithine

Tujioka

Yamada

Yokogoshi

et al. 2017

J Nutr Sci Vitaminol

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“…However, the positive correlation between the rate of protein synthesis and RNA activity was found in the brain of weaned rats when the dietary quality and quantity of protein were manipulated (Yokogoshi et al, 1992). Hormonal treatment such as insulin, thyroid hormone and estrogen also appeared to elevate the rate of protein synthesis and RNA activity in the brain (Hayase and Yokogoshi, 1995b;Hayase et al, 1997;Hayase et al, 2001). In the brain regions of rats in the present study, RNA activity, rather than RNA concentration in the soy protein -f-methionine group was higher than in the group fed the soy protein diet (Table IV).…”

Section: Discussionmentioning

confidence: 99%

Effect of Adding Dietary Methionine to a Low Soy Protein Diet on the Brain Protein Synthesis Rate in Ovariectomized Female Rats

Lyou

Tujioka²,

Hirano³

et al. 2004

Nutritional Neuroscience

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A deficiency of sex hormones affects brain function in mammals, including the decrease of protein synthesis. Recently, we have shown that the protein synthesis in the brain depended on the quality of dietary protein in ovariectomized female rats. The methionine is the first limiting amino acid for the recommended dietary allowance of amino acids in soy protein. The purpose of this study was to determine whether the addition of dietary methionine affected the rate of brain protein synthesis in ovariectomized female rats fed on the soy protein diet. Experiments were conducted on two groups of ovariectomized female rats (24 week) given the diets containing 5% soy protein or 5% soy protein + 0.2% methionine for 10 d. The fractional rates of protein synthesis in cerebral cortex and cerebellum significantly increased with an addition of dietary methionine. In the brain, the RNA activity [g protein synthesized/((g RNA) x d)] was significantly correlated with the fractional rate of protein synthesis. The RNA concentration (mg of RNA/g of protein) was not related to the fractional rate of protein synthesis in any organ. The results suggest that the addition of limiting amino acid for the low soy protein elevates the rate of protein synthesis in the brain of ovariectomized female rats, and that RNA activity is at least partly related to the fractional rate of brain protein synthesis.

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“…1,2) It is known that mTOR regulates cell growth and metabolism. mTOR signalling is activated by hormones, growth factors and amino acids.…”

Section: Influence Of Gaba On Brain Protein Synthesis Mediated By Thementioning

confidence: 99%

Influence of GABA on Brain Protein Synthesis Mediated by the Mammalian Target on the Rapamycin Pathway

Thanapreedawat

Ohsumi

Hayase

et al. 2013

Bioscience, Biotechnology, and Biochemistry

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Effect of a Thyroid Hormone Treatment on Brain Protein Synthesis in Rats

Cited by 10 publications

References 9 publications

Changes in Thyroid Hormone Are Not Involved in Regulating Brain Protein Synthesis in Adults Rats Fed Ornithine

Changes in Thyroid Hormone Are Not Involved in Regulating Brain Protein Synthesis in Adults Rats Fed Ornithine

Effect of Adding Dietary Methionine to a Low Soy Protein Diet on the Brain Protein Synthesis Rate in Ovariectomized Female Rats

Influence of GABA on Brain Protein Synthesis Mediated by the Mammalian Target on the Rapamycin Pathway

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