Yasuhiro Kido

Kyoto Prefectural University, Kioto, Kyōto, Japan

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Publications (15)28.95 Total impact

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    ABSTRACT: A precursor of protoporphyrin IX, 5-aminolevulinic acid (5-ALA) is employed as a prodrug for photodiagnosis and photodynamic therapy. Recently, it has been shown that 5-ALA reduces glucose levels during fasting and after glucose loading in prediabetic subjects. We hypothesized that 5-ALA ameliorates diabetic conditions through mitochondrial changes in visceral adipose tissue. In order to explore the metabolic effects on the type 2 diabetic state, we administered ALA hydrochloride in combination with sodium ferrous citrate (SFC) to Otsuka Long-Evans Tokushima Fatty (OLETF) rats at intragastric doses of 20 and 300 mg/kg/day for 6 weeks. The administration of 300 mg/kg/day of 5-ALA improved glucose intolerance, hypertriglyceridemia, and hyperleptinemia in OLETF rats more effectively than the administration of an equivalent dose of metformin, in accordance with reductions in food intake and body weight. Furthermore, the weight of the retroperitoneal fat tended to decrease and cellular mitochondrial content of the fat was markedly reduced by the 5-ALA administration, showing a positive correlation. These results suggest that 5-ALA ameliorates diabetic abnormalities in OLETF rats by reducing the visceral fat mass and mitochondrial content of adipocytes in a site-specific manner.
    Nutrition Research. 01/2014;
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    ABSTRACT: Studies have indicated that sports anemia is mainly associated with intravascular hemolysis induced by exercise. We hypothesized that such exercise-induced hemolysis leads to oxidative damage due to an increase in free iron caused by hematocyte destruction. Thirty-one male ICR mice were randomly divided into 3 groups: a rested control group, an intense-exercise group, and a group rested for 24 hours after intense exercise. The serum haptoglobin level of the intense-exercise group decreased compared with that of the rested control group, suggesting hemolysis. Tissue iron and protein carbonyl levels in the liver were increased after exercise, and the protein carbonyl level in the spleen on the day after exercise was significantly increased compared with that of the resting state. These results suggest that the spleen and liver, where extravascular hemolysis occurs, were subjected to oxidative modification by the free iron, which was released from large numbers of hemocytes that were destroyed due to the intense exercise.
    Nutrition and Metabolic Insights 01/2014; 7:1-6.
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    ABSTRACT: Medical nutrition therapy for the management of diabetes plays an important role in preventing diabetes complications and managing metabolic control. However, little is known about actual eating habits of individuals with type 2 diabetic mellitus (T2DM), especially in Japan. Therefore, we sought to (1) assess the dietary intake of individuals with T2DM, and (2) characterize their intake relative to national recommendations. This cross-sectional study involved 149 patients (77 males and 72 females) aged 40-79 years with T2DM recruited at a Kyoto hospital. Dietary intake was assessed using a validated self-administered diet history questionnaire. Under-consumption, adequacy, and over-consumption, of nutrients were compared to the age- and sex-based standards of the Japanese Dietary Reference Intakes. Among the results, most notable are (1) the inadequacy of diets in men with respect to intake of vitamins and minerals, likely owing to low intake of vegetables and fruits; (2) excess contributions of fat intake to total energy in both sexes; and (3) excess consumption of sweets and beverages relative to the national average. The prevalence of diabetes complications may be increasing because of a major gap between the typical dietary intake of individuals with T2DM and dietary recommendation.
    Nutrients 01/2013; 5(7):2276-2288. · 3.15 Impact Factor
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    ABSTRACT: Branched-chain amino acids (BCAA) can function as pharmacologic nutrients for patients with decompensated cirrhosis. However, the effects of BCAA at the early stage of chronic liver disease are not clear. We hypothesized that early BCAA supplementation would attenuate the progression of chronic liver disease. The present study examined the effects of BCAA supplementation on the progression of chronic liver disease in rats caused by injected carbon tetrachloride (CCl₄). Sprague-Dawley rats were fed with a casein diet (control group) or the same diet supplemented with BCAA (BCAA group) for 11 weeks, and all rats were repeatedly injected with CCl₄. Food intake did not significantly differ between control and BCAA groups during the experimental period. Plasma alanine aminotransferase activities gradually increased during the experimental period in both groups but peaked later in the BCAA group. Liver fibrosis was more evident in the control group. Levels of connective tissue growth factor messenger RNA were significantly lower in the livers of rats in the BCAA group than in the control group. Terminal deoxynucleotidyl transferase-mediated deoxyuridine 5-triphosphate nick end labeling assays found considerably more hepatic apoptosis in the control group. Liver cytosolic cytochrome c levels and expression of the proapoptotic Bax protein in the mitochondrial fraction were significantly lower in the BCAA group than in the control group. These results suggest that supplementation with BCAA delays the progression of chronic liver disease caused by CCl₄ in rats by attenuating hepatic apoptosis.
    Nutrition research (New York, N.Y.) 07/2012; 32(7):522-9. · 1.20 Impact Factor
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    ABSTRACT: We examined whether continuous supplementation with branched-chain amino acids phosphorylates ribosomal protein S6, a downstream effector of mammalian target of rapamycin, and improves hypoalbuminemia of rats with chronic liver disease. Sprague-Dawley rats were fed a casein diet (control group) or a branched-chain amino acid-supplemented casein diet (branched-chain amino acid group) for 11 weeks with repeated injections of carbon tetrachloride. Throughout this experimental period, no significant difference in plasma albumin concentration was seen between groups. The percentage of reduced albumin within total plasma albumin gradually decreased in both control and branched-chain amino acid groups. After 11 weeks with supplementation, phosphorylation of ribosomal protein S6 was significantly increased in the liver of rats in the branched-chain amino acid group compared with the control group. Furthermore, the percentage of reduced albumin within total albumin was significantly higher in the branched-chain amino acid group than in the control group. These results indicate that continuous supplementation with branched-chain amino acids in rats with chronic liver disease induces phosphorylation of hepatic ribosomal protein S6 and attenuates decreases in the percentage of reduced albumin, although levels of plasma albumin are not increased.
    Journal of Clinical Biochemistry and Nutrition 01/2012; 50(1):67-71. · 2.25 Impact Factor
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    ABSTRACT: The objective of this study was to investigate the effects of dietary medium-chain triglycerides (MCT) on hepatic lipid accumulation in growing rats with protein malnutrition. Weaning rats were fed either a low-protein diet (3%, LP) or control protein diet (20%, CP), in combination with or without MCT. The four groups were as follows: CP-MCT, CP+MCT, LP-MCT, and LP+MCT. Rats in the CP-MCT, CP+MCT and LP+MCT groups were pair-fed their respective diets based on the amount of diet consumed by the LP-MCT group. Rats were fed each experimental diet for 30 d. Four weeks later, the respiratory quotient was higher in the LP-MCT group than those in the other groups during the fasting period. Hepatic triglyceride content increased in the LP groups compared with the CP groups. Hepatic triglyceride content in the LP+MCT group, however, was significantly decreased compared with that in the LP-MCT group. Levels of carnitine palmitoyltransferase (CPT) 1a mRNA and CPT2 mRNA were significantly decreased in the livers of the LP-MCT group, as compared with corresponding mRNA levels of the other groups. These results suggest that ingestion of a low-protein diet caused fatty liver in growing rats. However, when rats were fed the low-protein diet with MCT, hepatic triglyceride deposition was attenuated, and mRNA levels encoding CPT1a and CPT2 were preserved at the levels of rats fed control protein diets.
    Journal of Nutritional Science and Vitaminology 01/2011; 57(2):138-43. · 0.99 Impact Factor
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    ABSTRACT: Currently, protein requirements are generally determined based on nitrogen balance studies, but there are a variety of limitations associated with this method. The indicator amino acid oxidation (IAAO) method, with a theoretical base that differs widely from the nitrogen balance method, was developed as an alternative method for humans. The objective of the present study was to evaluate protein intakes for metabolic demands and protein quality, using protein itself, in rats employing the IAAO technique with L-[1-(13)C]phenylalanine. Male Wistar/ST rats (5-6 wk old) received a graded casein (4.3, 8.6, 12.9, 17.2, 21.5, 25.8%), or a wheat gluten (7.2, 10.8, 14.4, 18.0, 21.6, 25.2%) diet, along with L-[1-(13)C]phenylalanine. An isotopic plateau in breath was achieved 210 min after the start of the (13)C ingestion. The protein intakes for metabolic demands were calculated by applying a mixed-effect change-point regression model to breath (13)CO(2) data, which identified a breakpoint at minimal breath (13)CO(2) in response to graded protein intake. The protein intakes for metabolic demands determined by the IAAO method were 13.1 g/kg BW/d for casein and 18.1 g/kg BW/d for wheat gluten, showing a tendency similar to that determined by the nitrogen balance method. These results demonstrated that the IAAO method could be employed to evaluate not only the protein intakes for metabolic demands, but the dietary protein quality in freely living rats, suggesting that this method might be viable in a clinical setting.
    Journal of Nutritional Science and Vitaminology 01/2011; 57(6):418-25. · 0.99 Impact Factor
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    ABSTRACT: Iron deficiency anemia (IDA) is one of the most serious forms of malnutrition. This experiment was conducted to investigate whether acidic xylooligosaccharide (U-XOS), expected to have a high iron bioavailability, was useful in the prevention of iron deficiency. Experiment 1: Nineteen female Sprague-Dawley rats (20 wk old) were fed three different diets for 28 d; a U-XOS-supplemented low-iron diet (LI-X, n=7), a low-iron diet (LI, n=6), and a control diet (C, n=6). On day 28, the LI-X and LI groups showed iron deficiency without anemia. A significant difference in the total and unsaturated iron binding capacity, and serum transferrin saturation level was shown in the LI-X and LI groups, compared with the C group. However, the decrease of hepatic iron content of the LI-X group was suppressed compared with the LI group. Experiment 2: Eleven male Sprague-Dawley rats (7 wk old) were fed a U-XOS-supplemented diet (X, n=5) or a control diet (C, n=6) for 7 d. No significant difference in body weight gain or food intake was demonstrated between the two groups; the apparent iron absorption rate of the X group increased clearly compared with that of the C group. These results suggested that a U-XOS diet could preserve storage of hepatic iron in adult female rats fed a low-iron diet and could prevent IDA by promotion of dietary iron absorption, inhibition of iron excretion, and/or improvement of iron bioavailability.
    Journal of Nutritional Science and Vitaminology 01/2011; 57(4):292-7. · 0.99 Impact Factor
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    ABSTRACT: Diabetic nephropathy is associated with lipid deposits in the kidney. We hypothesized that a diet containing polyunsaturated fatty acids (PUFAs) could ameliorate pathogenesis of diabetic kidney diseases associated with lipid depositions in the kidneys. We examined if the pathogenesis and progression of diabetic nephropathy are affected by the type of dietary fat using streptozotocin (45 mg/kg body weight, intravenous)-induced diabetic rats (5-week-old male Sprague-Dawley rats). Streptozotocin-induced diabetic rats were fed a lard diet containing saturated fatty acids or a rapeseed oil diet containing PUFAs (DML and DMR, respectively) for 11 days. Similarly, streptozotocin-nontreated rats were fed a lard diet or a rapeseed oil diet (NL and NR, respectively) for 11 days. Hyperglycemia was induced in DML and DMR, compared with NL and NR groups. The levels of plasma ketone, total cholesterol, and triglyceride (TG) were significantly increased in the DML group. Moreover, albuminuria and renal TG content were enhanced in the DML group. The renal TG content correlated positively with urinary albumin excretion (P < .001). Oil-Red O staining of kidney sections indicated a marked accumulation of neutral lipids in both glomerular and tubular cells in the DML group. In addition, a renal sterol regulatory element-binding protein-1 mature protein increment was induced in the DML group. Conversely, sterol regulatory element-binding protein-1 expression in the kidney was maintained at normal levels in the DMR group. These results suggest that dietary PUFAs may slow the progression of diabetic nephropathy associated with lipid depositions in the kidney.
    Nutrition research (New York, N.Y.) 03/2010; 30(3):217-25. · 1.20 Impact Factor
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    ABSTRACT: We examined whether two types of xylooligosaccharides (neutral or acidic xylooligosaccharides) derived from hardwood kraft pulp ameliorate the development of atopic dermatitis (AD)-like skin lesions induced by repeated application of picryl chloride (PiCl) in NC/Nga mice. Oral administration of acidic xylooligosaccharides at a daily dose of 100 mg/kg significantly prevented the development of AD-like skin lesions. Serum histamine level was significantly suppressed, but serum total IgE level was not significantly suppressed. Moreover, the secretion of inflammatory cytokine IL-12 from splenic lymphocytes was significantly suppressed. On the other hand, neutral xylooligosaccharides showed no significant preventive effect on the development of AD-like symptoms. These results suggest that oral administration of acidic xylooligosaccharides may be effective in preventing the development of AD-like skin disease and one of the mechanisms is the suppressive effect on IL-12.
    Journal of Nutritional Science and Vitaminology 01/2010; 56(1):54-9. · 0.99 Impact Factor
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    ABSTRACT: The introduction of the tumorigenic v-Ha-ras oncogene-transformed rat liver epithelial cells (WBras), which is deficient in gap junctional intercellular communication (GJIC), into F344 rats, induces significant formation of hepatocellular tumors. GJIC plays a major role in maintaining tissue homeostasis. Using this in vivo tumor model system, we used 2-dimensional electrophoresis with isoelectric focusing in the first dimension and SDS-PAGE in the second dimension to globally identify proteins that are uniquely expressed in the livers of WBras-treated rats as compared to the sham control. Immunoblotting was used to identify Ras and Connexin43, which were the positive and negative marker proteins, respectively, of the introduced WBras cells. As predicted, immunoblotting indicated that the whole liver of tumor-bearing animals exhibited a decreased level of Connexin43 and an increased level of Ras. Connexin43 and GJIC were expressed and functional in normal liver, but not in the tumor. In addition to these 2 markers, an additional 4 proteins exhibited decreased levels and 2 proteins exhibited increased levels in the livers of tumor-bearing animals. N-Terminal sequencing analysis was used to identify these proteins, which were glucose-regulated protein 78, 2 isoforms of heat shock protein 60, and the beta-chain of ATP synthase for the down regulated proteins, and beta-Actin with a 46 amino acid deletion from its N-terminus and Vimentin with a 71 amino acid deletion from its N-terminus for the up regulated proteins. These data offer potentially new markers of liver tumorigenicity, particularly, Vimentin. (
    International Journal of Cancer 01/2009; 124(11):2512-9. · 6.20 Impact Factor
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    ABSTRACT: Our recent study demonstrates that polypyrimidine tract-binding protein (PTB), which is a sequence specific RNA-binding protein, attenuates albumin synthesis in a cell-free translation system. In this study, the effects of food intake on regulation of albumin synthesis through binding of PTB to albumin messenger RNA (mRNA) were investigated. Rats were divided into 1 of 3 groups: fed; fasted for 36 h; or fasted for 36 h and then refed for 24 h. No significant differences in albumin mRNA levels were found among fed, fasted and refed rats. However, a decrease in the proportion of albumin mRNA associated with polysomes was identified in fasted rats. Furthermore, UV-cross linking analysis demonstrated that levels of albumin mRNA-PTB complex were increased in liver extracts from fasted rats. No significant differences in PTB levels in liver homogenate were found among the experimental groups. However, PTB level in the cytoplasmic fraction was higher in fasted rats than in fed rats. In refed rats, PTB level in the cytoplasmic fraction returned to a level comparable to that in fed rats, but was inhibited by treatment with rapamycin, a mammalian target of rapamycin (mTOR) inhibitor. These results suggest that localization of PTB is regulated by food intake through mTOR signaling, and alterations in level of albumin mRNA-PTB complex play a role in mediating the effects of food intake on albumin synthesis in the rat liver.
    Journal of Nutritional Science and Vitaminology 05/2008; 54(2):142-7. · 0.99 Impact Factor
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    ABSTRACT: In order to determine pyroglutamic acid levels in plasma, we developed a method based on precolumn derivatization of the carboxyl group of pyroglutamic acid with 2-nitrophenylhydrazine. Eight-week-old male SD strain rats were administered 200 mg of an acidic peptide fraction obtained from a commercial wheat gluten hydrolysate containing 0.63 mmol/g pyroglutamyl peptide. After administration, significant amounts of free pyroglutamic acid were observed in the ethanol-soluble fraction of the plasma from the portal vein. In addition, pyroglutamate aminopeptidase digestion of the ethanol-soluble fraction liberated significant amounts of pyroglutamic acid, which indicated the presence of the pyroglutamyl peptide. The presence of the pyroglutamyl peptide in the plasma was further confirmed by size exclusion chromatography. The levels of free and peptide forms of pyroglutamic acid increased significantly and reached a maximum (approximately 40 nmol/mL) at 15 and 30 min after administration, respectively.
    Journal of Agricultural and Food Chemistry 10/2006; 54(19):6984-8. · 2.91 Impact Factor
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    ABSTRACT: In the present study, we identified several food-derived collagen peptides in human blood after oral ingestion of some gelatin hydrolysates. Healthy human volunteers ingested the gelatin hydrolysates (9.4-23 g) from porcine skin, chicken feet, and cartilage after 12 h of fasting. Negligible amounts of the peptide form of hydroxyproline (Hyp) were observed in human blood before the ingestion. After the oral ingestion, the peptide form of Hyp significantly increased and reached a maximum level (20-60 nmol/mL of plasma) after 1-2 h and then decreased to half of the maximum level at 4 h after the ingestion. Major constituents of food-derived collagen peptides in human serum and plasma were identified as Pro-Hyp. In addition, small but significant amounts of Ala-Hyp, Ala-Hyp-Gly, Pro-Hyp-Gly, Leu-Hyp, Ile-Hyp, and Phe-Hyp were contained.
    Journal of Agricultural and Food Chemistry 09/2005; 53(16):6531-6. · 2.91 Impact Factor
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    ABSTRACT: Epsilon-polylysine (epsilon-PL) has been used as a food additive in Japan for many years. In this study, it inhibited human and porcine pancreatic lipase activity in substrate emulsions containing bile salts and phosphatidylcholine, in the concentration range of 10-1000 mg/L. At the same concentrations, it also destroyed the emulsifying activity, suggesting that lipase inhibitory activity and emulsion breakdown activity were associated. Epsilon-PL inhibited porcine pancreatic lipase activity and destroyed emulsion breakdown activity at 1000 mg/L in the substrate containing bile salts and phosphatidylcholine alone. Epsilon-PL did not inhibit lipase activity or affect emulsifying activity at 1000 mg/L in the substrates containing arabic gum and polyvinyl alcohol. A comparison of lipase inhibitory activity between epsilon-PL and three types of alpha-PL with differing polymerization rates was performed. The lipase inhibitory activity of epsilon-PL was not different from that of alpha-PL (44 lysine residues). Epsilon-PL maintained its inhibitory activity after incubation with trypsin, alpha-chymotrypsin and pepsin, whereas alpha-PL did not. The effect of epsilon-PL on postprandial hypertriacylglyceridemia was investigated in rats. The plasma triacylglycerol concentration in rats intragastrically administered > or =15 mg/kg of both fat emulsion and epsilon-PL was significantly lower at 2 and 3 h after administration than that in rats administered fat emulsion alone (P < 0.05). These results strongly suggest that epsilon-PL is able to suppress dietary fat absorption from the small intestine by inhibiting pancreatic lipase activity.
    Journal of Nutrition 06/2003; 133(6):1887-91. · 4.20 Impact Factor