グレリンの腹腔内投与が栄養素選択的な摂食調節に及ぼす影響

グレリンは２８個のアミノ酸から構成されるペプチドであり、その中枢あるいは末梢投与は、その後の摂食量を増加させることが報告されている。本研究ではグレリンの栄養素の嗜好性への影響を検討するため、３種類のマクロ栄養素食（糖質、タンパク質及び脂質）を同時に与えたラットにグレリン（０.５，１.０及び ５.０nmol/rat）を腹腔内投与し、投与から１、２、４及び２４時間後の摂食量を測定した。総摂食量はグレリンの投与量依存的に、生理的食塩水投与時と比べて増加した。その内訳を見ると、糖質食の摂食量が有意に増加していたが、タンパク質及び脂質食の摂食量に変化は見られなかった。血清グルコース、総タンパク質、中性脂肪、遊離脂肪酸、及びβ-リポタンパク質濃度はグレリン投与による影響は認められなかった。本研究はグレリンが代謝に影響することなく、糖質の摂食量を選択的に増加させたことを明らかにした。この結果は、グレリンが直接的に糖質に選択的な摂食調節に関与していることを示唆している。Ghrelin is a 28-amino acid peptide with an acyl side chain, n-octanoic acid. It was reported that ghrelin infusion centrally and peripherally increases food intake. In this study, to investigate the effect of ghrelin to preference on nutrients, we infused ghrelin (0.5, 1.0 and 5.0 nmol/rat) intraperitoneally to rats, which were fed simultaneously three macronutrient diets (carbohydrate, protein and fat), and measured food intakes at 1, 2 and 4hr after infusion. Infusions of ghrelin increased dose-dependently total food intake compared with saline infusion. Infusion of ghrelin increased significantly carbohydrate intake, although protein and fat intakes did not altered. Serum glucose, total protein, albumin, triglyceride, free fatty acid and β-lipoprotein levels were did not altered with infusion of ghrelin. This study defined that ghrelin infusion increased selectively carbohydrate intake without metabolic changes. This result suggests that ghrelin may participate directly with the selective control of carbohydrate intake

グレリンの脳室内投与が栄養素選択的な摂食調節に及ぼす影響

グレリンは２８個のアミノ酸から構成されるペプチドであり、その中枢あるいは末梢投与は、その後の摂食量を増加させることが報告されている。本研究ではグレリンの栄養素の嗜好性への影響を検討するため、３種類のマクロ栄養素食（糖質、タンパク質及び脂質）を同時に与えたラットにグレリン（１００、２００及び ５００ pmol/rat）を脳室内投与し、投与から１、２、４及び２４時間後の摂食量を測定した。２００及び ５００ pmol のグレリン投与は２時間後までの累積総摂食量を、生理的食塩水投与時と比べて有意に増加させた。その内訳を見ると、糖質食及びタンパク質食の累積摂食量が有意に増加していたが、脂質食の摂食量に変化は見られなかった。本研究はグレリンの脳室内投与が糖質及びタンパク質の摂食量を選択的に増加させたことを明らかにした。この結果は、グレリンによる栄養素選択的な摂食調節が行われるメカニズムにおいて迷走神経が関与している可能性を示唆している。Ghrelin is a ２８-amino acid peptide with an acyl side chain, n-octanoic acid.　It was reported that ghrelin infusion centrally and peripherally increases food intake.　In this study, to investigate the effect of ghrelin to preference on nutrients, we infused ghrelin centrally（１００, ２００ and ５００ pmol/rat）to three macronutrient diets（carbohydrate, protein and fat）fed rat and measeured food intake at １, ２, ４ and ２４ hours after the infusions.　The central infusion of ２００ and ５００ pmol of ghrelin increased cumulative total food intake until ２ h after infusion compared with saline infusion.　In regards to the three diets, carbohydrate and protein intakes were increased.　But the infusion of ghrelin did not alter fat intake.　In this study, we demonstrate the alternation of preference in nutrients, especially carbohydrate and protein, by central ghrelin infusion.　It is known that two types of nerve systems involve the orexigenic action of ghrelin；ghrelin neurons in arcuate nucleus and vagal nurves.　The differences of preferense of nutrients observed in this study may result from the differences of those nervous systems

コウウンドウセイ モデル ラット SPORTS ノ カイバ ニオケル ノルエピネフリン ドウタイ ト ジハツ ウンドウリョウ

Reduced physical exercise activity contributes to the development of several metabolic disorders including obesity, type ２ diabetes and hypertension. Especially in the developed countries, many people choose not to be active physically, possibly because of a reduced motivation to participate in exercise activities. Thus, augmentation of exercise motivation and subsequent increase in the physical activity would reduce an incidence of these metabolic disorders. In order to clarify the psychological mechanisms responsible for an increased exercise activity, we have generated and established a line of SPORTS （Spontaneously-Running-Tokushima-Shikoku） rat for high levels of voluntary wheel running. Male SPORTS rats run voluntarily in the running wheel almost six times longer than control Wistar rats. Here we examined the relation of the running activity of SPORTS rat with the hippocampal norepinephrine （NE） system including the levels of NE, adrenergic receptors, and degradation enzymes for monoamines. In the hippocampus of SPORTS rats, the level of NE in extracellular fluid was augmented, whereas the level in the homogenate of the whole tissue was decreased even for sedentary conditions. The level of striatal dopamine has not altered in both groups. The protein expression and the activity levels of monoamine oxidase A （MAOA）, a critical enzyme for the degaradation of NE, were decreased in the hippocampus of SPORTS rats to increase extracellular NE level. Thus, inhibition of oxidase activity in normal Wistar rats markedly increased wheel running activity. Our results indicate that the hippocampal NE determines the neural basis of the psychological regulation of exercise behavior in SPORTS rats. Modulation of NE transmission in the hippocampus will be a good method for enhancing the exercise behavior both in clinical patients and in healthy humans

High Level Estradiol Induces EBV Reactivation and EBV gp350/220(+)CD138(+) Double-positive B Cell Population in Graves’ Disease Patients and Healthy Controls

Graves’ disease occurs predominantly in women. Epstein-Barr virus (EBV) mainly persists in human B lymphocytes, and its reactivation stimulates antibody production. We previously suggested that the EBV reactivation-induced production of TRAb and IgM at 100 nM estradiol (pregnant level) was lower than that at 0 nM estradiol and that class switch recombination may be increased by estradiol. In this study, we examined the effect of estradiol on EBV reactivation. We identified the expression of EBV-glycoprotein 350/220 (gp350/220) in the late phase of reactivation and plasma cell differentiation of EBV-infected cells using 72A1 antibody and CD138 antibody, respectively. We found the mean ratio of gp 350/220(+) CD138(+) cells at 100 nM estradiol was higher than that at 0 nM estradiol. These results suggested that EBV-infected cells could survive with keeping the ability of antibody production in 100 nM estradiol, which is consistent with the improvement of Graves’ disease during maternity and exacerbation postpartum

Castor bean cake in top-dressing application as a source of nitrogen on the production and quality of zucchini organic seeds

Studies in vegetables show that fertilization influences seed production positively, however, when the quality of the seeds is analyzed, the results are mostly inconsistent. The objective of this study was to evaluate the effect of castor bean cake (CBC) dose splitting in top-dressing application on the production and quality of zucchini organic seeds, as well as its effect on the macronutrient content of fruits and seeds. The experimental design was a randomized block design and four replications. There were 13 treatments with four doses of CBC in top-dressing (1.7, 3.4, 5.1 and 6.8 t ha-1) per three applications (33.3-33.3-33.3%, 50-50% and 33-50-17%) and the control treatment without any kind of top-dressing fertilization. The study evaluated the number of ripe fruits per plant, the production (number and mass) of seeds per fruit and per plant, the mass of one hundred seeds, seed germination, first germination count, and macronutrient content in the diagnosis leaf, in mature fruits (without seeds) and seeds. The number of ripe fruits per plant was not affected by the CBC doses in top-dressing, neither by the splitting of the applications. It was observed that the number of seeds per fruit, mass of seeds per fruit and mass of seeds per plant showed quadratic behavior. Regarding seed quality, only the 1.7; 3.4 and 5.1 t ha-1 doses produced seed with superior quality than the other doses. In conclusion, the CBC doses increased the number of seeds per fruit, mass of seeds per fruit and per plant up to the 4.5t ha-1 dose, approximately

Identification of cis-acting promoter sequences required for expression of the glycerol-3-phosphate acyltransferase 1 gene in mice

Glycerol-3-phosphate acyltransferase 1 (GPAT1) is a rate limiting enzyme in de novo glycerophospholipid synthesis. The murine GPAT1 promoter sequence (the “classical” sequence) was reported previously. However, the organization of this DNA sequence does not fully match the mouse genome sequences on NCBI/GenBank. Here we have identified net cis-acting promoter sequences for the mouse GPAT1 gene: promoter 1a which includes part of the classical sequence and the downstream promoter 1b. Promoter 1a facilitates transcription of two alternative GPAT1 transcript variants, GPAT1-V1 and V2, while promoter 1b produces a third transcript variant, GPAT1-V3. Upstream stimulating factor-1 (USF-1) controlled both promoters whereas sterol regulatory element-binding protein-1 (SREBP-1) exclusively regulated promoter 1a activity in vitro. Feeding increased GPAT1-V1 and V2, but not V3 mRNA levels in mouse liver. The obese condition of db/db mice did not alter the hepatic expression levels of any of the three GPAT1 variants. Feeding enhanced hepatic mRNA levels, intranuclear protein levels and promoter 1a-binding levels of SREBP-1, but not of USF-1. Thus, promoter 1a was exclusively activated by routine feeding in vivo. Our results indicate differential roles of the two promoters in the regulation of hepatic GPAT1 gene expression in mice

Utility of contrast-enhanced 3D STIR FLAIR imaging for evaluating pituitary adenomas at 3 Tesla

Purpose: To assess the usefulness of contrast-enhanced 3D STIR FLAIR imaging for evaluation of pituitary adenomas. Methods: Patients with pituitary adenomas underwent MR examinations including contrast-enhanced 3D STIR FLAIR and 2D T1-weighted (T1W) imaging. We subjectively compared the two techniques in terms of 10 categories. In addition, images were rated by side-by-side comparisons into three outcomes: 3D STIR FLAIR imaging superior, equal, or 2D T1W imaging superior. Additionally, the added value of 3D STIR FLAIR imaging for adenoma detection over conventional MR imaging was assessed. Results: Twenty-one patients were included in this study. 3D STIR FLAIR imaging offered significantly better images than 2D T1W imaging in terms of three categories, including overall visualization of the cranial nerves in the cavernous sinus (mean 4.0 vs. 2.8, p < 0.0001), visualization of the optic nerves and chiasm (mean 4.0 vs. 2.6, p < 0.0001), and severity of susceptibility artifacts (mean 0.0 vs. 0.4, p = 0.004). In the side-by-side comparison, 3D STIR FLAIR imaging was judged to be significantly superior to 2D T1W imaging for overall lesion conspicuity (62% vs. 19%, p = 0.049) and border between the adenoma and the pituitary gland (67% vs. 19%, p = 0.031). The addition of 3D STIR FLAIR imaging significantly improved the adenoma detection of conventional MR imaging. Conclusion: 3D STIR FLAIR imaging improved overall lesion conspicuity compared to 2D T1W imaging. We suggest that 3D STIR FLAIR imaging is recommended as a supplemental technique when pituitary adenomas are invisible or equivocal on conventional imaging