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Volume 43 (1997)
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- Issue 5 Pages 491-
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- Issue 3 Pages 271-
- Issue 2 Pages 167-
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Volume 43, Issue 3
Displaying 1-13 of 13 articles from this issue
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Hong ZHANG, Kazumi OSADA, Hideyuki SONE, Yuji FURUKAWA1997 Volume 43 Issue 3 Pages 271-280
Published: 1997
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSThe effect of biotin administration on the glucose tolerance of streptozotocin (STZ)-induced diabetic Wistar rats was investigated. STZ-induced diabetes was induced by intraperitoneal injection of strepto-zotocin (45 mg/kg body weight as a single dose). The impaired glucose tolerance in response to an oral glucose load (1.8 g per kg body weight) in STZ-induced diabetic rats (STZ-rat) was partially improved by intra-peritoneal administration of biotin for 15 days (100, ag/rat/day). Howev-er, a recovery in the STZ-rat's insulin secretion was not found after biotin administration. To help clarify the mechanism underlying the improve-ment in glucose tolerance seen with biotin treatment, glucokinase and hexokinase activities were determined in the liver and pancreas. In STZ-rats that had received biotin (STZ-biotin rats), glucokinase activity was higher by 3.4-fold in liver and by 2.4-fold in pancreas than in the STZ-rats. The biotin level of STZ-rats was significantly lower in the liver and pancreas than that of the control rats (no STZ administration); but in STZ-biotin rats, the level in these organs recovered to the control level. These results demonstrate that injected biotin can improve glucose handl-ing without increasing insulin secretion in STZ-rats.View full abstractDownload PDF (1059K) -
Chan-Kyeong PARK, Yoshiko ISHIMI, Mineko OHMURA, Michio YAMAGUCHI, Sac ...1997 Volume 43 Issue 3 Pages 281-296
Published: 1997
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSThe action of retinol and carotenoids on bone cells was investigated in vitro by evaluating cell growth, alkaline phosphatase activ-ity and the mRNA expression of a differentiation marker protein of osteoblastic cells. The clonal osteogenic cell line MC3T3-El, established from newborn mouse calvaria, has a capacity of differentiation into osteoblast and mineralization in vitro. Retinol and β-carotene inhibited the proliferation of MC3T3-E1 cells as well as DNA synthesis of the cells in a dose-dependent manner. Retinol induced differentiation of the MC3T3-E1 cells, by increasing alkaline phosphatase activity dose depen-dently, in a range from 1 to 100nM. Beta-carotene increased alkaline phosphatase activity in a dose-related manner in a range from 0.1 to 5μM. Osteopontin is one of the matrix proteins which osteoblasts produce. Retinol increased the expression of osteopontin mRNA in a range from 1 to 100 nM. Beta-carotene also increased osteopontin mRNA expression, reaching a plateau at 1μM. The induction of differentiation of MC3T3-E 1 cells by β-carotene was dose-dependent but was two orders of magni-tude less active than that produced by retinoids. Within the MC3T3-El cells, part of the β-carotene was effectively converted into retinol. Alpha-carotene, canthaxanthin and lycopene also inhibited cell proliferation at μM and increased alkaline phosphatase activity and osteopontin mRNA expression, but less potently so than β-carotene. Retinol and carotenoids were concluded to have a direct stimulatory effect on the differentiation of osteoblasts at the physiological concentration.View full abstractDownload PDF (1969K) -
Shino NEMOTO, Megumi OTSUKA, Nobuhiko ARAKAWA1997 Volume 43 Issue 3 Pages 297-309
Published: 1997
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSThis study showed that the inhibition of cell growth in 3T6, induced by the supplementation of ascorbate at 0.5mM in cultured medium, was prevented by the addition of catalase in the range of 25-750 units/mL regardless of the degree of activity. However, cytotoxicity induced by concentrations of more than 2 mM ascorbate could not be prevented even when a high level of catalase (5, 000 units/mL) was added to the medium. Catalase activity in medium supplemented with ascorbate decreased with incubation time; the higher the concentration of ascorbate, the greater the decrease in catalase activity. These results indicate that even though catalase is present at a high concentration in the medium, it cannot prevent cytotoxicity by a high concentration of ascorbate because the oxygen radical derived from ascorbate inhibits its activity. We therefore investigated whether the inhibition of catalase activity by ascor-bate could be observed in animal tissues. The catalase activity in the tissues of guinea pigs 6 h after the administration of ascorbate was lower than that in non-administered animals. When guinea pigs were fed diets containing 5 mg or 100 mg ascorbate/d/animal over a 90 weeks period, a clear affect on catalase activity in the high-dose ascorbate group as compared to that in the low-dose ascorbate group was not observed.View full abstractDownload PDF (1363K) -
Misako OKITA, Kazuhiko SUZUKI, Takayo SASAGAWA, Junko YAMAMOTO, Ayumu ...1997 Volume 43 Issue 3 Pages 311-326
Published: 1997
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSTwo groups of rats, ethanol-treated and sucrose-admin-istered control rats, were fed diets with different AA content (0, 2 and 3 % weight) for 14 days. Ethanol was administered by gavage at a single daily dose of 3 g/kg body weight. The ethanol-treated rats showed significantly higher levels (p<0.01) of serum ALT activity. The dietary AA supple-ment lowered the serum ALT activity and liver triglyceride both in control and ethanol-treated rats. Significantly lower levels of 20: 4n-6 and 20: 4n-6/18 : 2n-6 ratio and higher levels of 18: In-9 in both the serum and liver triglyceride were observed in the ethanol-treated rats. The AA-supplemented diet induced a marked increase of 20: 4n-6 and subsequent significant decrease of 18 : 2n-6 both in the liver and serum phospholipid in control and ethanol-treated rats. 18: In-9 in the serum and liver tri-glyceride in both groups was also markedly decreased by AA supplement. No significant difference was observed in the liver 6-keto-PGFia level between the ethanol-treated and control rats. In the ethanol-treated rats, the level of 6-keto-PGFIa was elevated in the rats fed the 3 % AA supplemented diet. Though the liver leukotriene B4 levels were increased by ethanol administration in all rats, these levels were not increased by dietary AA.View full abstractDownload PDF (3274K) -
Kazuhiro AIBA, Masahiro KIMURA, Shigeko SAKATA, Koichi MATSUDA, Masae ...1997 Volume 43 Issue 3 Pages 327-343
Published: 1997
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSRats fed a Zn-deficient diet develop a characteristic cyclic variation in feed intake (Mills et al., Am J Clin Nutr 22: 1240-1249 (1969)). A preliminary analysis (Tamaki et al., Br J Nutr 73: 711-722 (1995)) of the cyclic variations was followed with a personal computer. Cosinor analysis revealed that the cyclic period of the feed intake of male rats was 3.5±0.05 d. The mesor, amplitude and acrophase value were 10.0±0.3g/d, 4.4±0.2g/d and 3.5±0.3 radian, respectively. The cycle of body-weight change of the Zn-deficient rats was well synchronized with that of feed intake. The parameters of the feed intake cycle had a high correlation to the corresponding parameters of body-weight change (mesor: r=0.846; amplitude: r=0.771; period: r=0.925; acrophase: r=0.452). With the supplementation of Zn (0.95-3.80mg/kg of the Zn-deficient diet), cyclic variations in feed intake and body-weight change were also found. The mesor, amplitude and period of feed intake cycle were in good correlation with Zn intake (r-0.856, p<0.001, r=-0.804, p<0.001 and r=0.613, p<0.01, respectively). The cycle of feed intake of the rats fed a Zn-free diet was simulated to be: mesor 9.7±0.1 g/d, amplitude 6.5±0.1 g/d and period 3.4±0.02 d. The concentration of Zn intake given the half-maximal value of the amplitude was assumed to be 56±1, ag/d.View full abstractDownload PDF (1664K) -
Kiyotaka NAKAGAWA, Sung-Do KANG, Dong-Ki PARK, Garry J. HANDELMAN, Ter ...1997 Volume 43 Issue 3 Pages 345-355
Published: 1997
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSTo evaluate the antioxidant effects of 48-carotene and asta-xanthin, rat liver microsomes were exposed to a mixture of chelated iron (Fe3+/ADP) and NADPH. The carotenoids (190 pmol/mg protein) were incorporated into some of these microsomal membranes, and phospho-lipid hydroperoxides (PLOOH), thiobarbituric acid reactive substances (TBARS) and endogenous a-tocopherol content were measured over time after the initiation of oxidant stress. In control microsomes, oxidant stress led to accumulation of 1, 865 (+/-371) pmol PLOOH/mg protein during the initial 10-min peroxidation reaction, followed by a more gradual increase during the subsequent 20-min of reaction. PLOOH accumulation during the initial 10-min reaction period was reduced to 588 (+/-169) pmol/mg protein with β-carotene present and 800 (+/-288) pmol/mg protein with astaxanthin present. During the following 20-min of incubation, PLOOH levels declined in the carotenoid-supplemented microsomes but continued to increase at a slower rate in control prepara-tions. TBARS did not show such large accumulation as observed in PLOOH during the initial 10-min incubation in any microsomal sample. The presence of carotenoids in the microsomal membrane partially in-hibited the loss of a-tocopherol, especially during the later phase of oxidant stress. When lipid peroxidation is generated by membrane-bound cyt-P450, the specific measurement of PLOOH clearly demonstrates that the presence of carotenoids provides antioxidant protection.View full abstractDownload PDF (1236K) -
Hiroko KIKUCHI-HAYAKAWA, Makiko KIMURA, Masaaki WATANUKI1997 Volume 43 Issue 3 Pages 357-368
Published: 1997
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSWe studied the adaptational effect of galactooligosaccha-ride (GOS) on the concentration of organic acids in cecal content, fecal water content and organic acid production from GOS in cultures with the cecal inocula of rats fed GOS for 1, 2, 7 or 21 d. The fecal water content of rats fed GOS for 1 d was higher than that of the controls. The concentration of each organic acid in the cecal contents was affected by diet, not by the time of adaptation. In in vitro fermentation, lactic acid was produced rapidly and remained in the cultures with homogenates of rats fed GOS for 1 d. Acetic acid in the cultures of the GOS-diet rats' cecal homogenates was produced more rapidly than that of the controls on days 2, 7 and 21 of adaptation. Propionic acid was produced more rapidly in the GOS homogenate cultures than in that of the controls on day 2. Butyric acid in the cultures from the GOS-fed rats was produced more rapidly than that of the controls on days 2 and 21. These results suggest that the time period of GOS feeding influenced the production rate of each organic acid, and the changes varied among acids.View full abstractDownload PDF (1324K) -
Asako YAMAMOTO, Akiko SEKINO, Mikie TAJIMA, Chuyen NGUYEN, Ikuko EZAWA1997 Volume 43 Issue 3 Pages 369-375
Published: 1997
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSThe purpose of this study was to investigate the effects of different degrees of alcohol ingestion on bone strength and mineraldensity. Three different groups of growing female rats were administered different doses of an alcohol-water solution for a period of 6 months. These three groups were divided into: 1) the control group, which was only given water; 2) the moderate group, which was given 5% ethanol solution for only 2 h per day; and 3) the excess group, which was given only 5 % ethanol solution for 163 days. This ethanol consumption induced no detrimental effect on biochemical parameters including liver function. The moderate group showed significantly higher (p<0.05) levels of proximal metaphysis as compared to the control group, while there was no difference between the excess group and the control group. Similarly, in comparison to the control group, the moderate group ex-hibited a significant increase (p<0.001) in bone mechanical strength, while the excess group showed either the same or decreased bone stiffness. These results indicate that alcohol intake has both beneficial and hinder-ing effects on the skeleton, depending on the concentration and frequency of ethanol intake.View full abstractDownload PDF (791K) -
Motoko OARADA, Nobuyuki KURITA, Makoto MIYAJI1997 Volume 43 Issue 3 Pages 377-385
Published: 1997
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSMethyl linoleate hydroperoxides (MLHPO) and 2, 2'-azo-bis(2-amidinopropane)dihydrochloride (AAPH), a widely used free rad-ical initiator, were examined for effects on antibody production by spleen cells using plaque-forming cell response against sheep red blood cells (SRBC). The in vitro primary antibody response was enhanced in the presence of MLHPO at a concentration range of 2-20μM or AAPH at 0.1 #M, but was suppressed with higher concentrations of these compounds. In the in vitro secondary antibody response, both MLHPO and AAPH failed to increase plaque-forming cell response above that of the control culture. Following the oral administration of MLHPO (2.29 g/kg) four times to mice, in vivo primary plaque-forming cell response was signifi-cantly suppressed. After, a single intraperitoneal injection of AAPH (60 mg/kg) to mice, in vivo primary plaque-forming cell response was also suppressed. These findings suggest that primary antibody response can be affected by lipid hydroperoxides and oxygen radicals in vivo.View full abstractDownload PDF (982K) -
Role of Ornithine Transport into Mitochondria in Urea Synthesis of Rats Treated with Thyroid HormoneYaeko NAGANUMA, Kazutoshi HAYASE, Akira YOSHIDA1997 Volume 43 Issue 3 Pages 387-396
Published: 1997
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSThe purpose of this study was to find whether or not the ornithine transport into mitochondria regulated urea synthesis when the
thyroid status is manipulated. Experiments were done on three groups of rats: given 6-propyl-2-thiouracil (PTU, a thyroid inhibitor) without tri-iodothyronine (T3) treatment, treated with PTU+T3 or receiving neither PTU nor T3 (control). The urinary excretion of urea, liver concentration of ornithine and ornithine transport into isolated hepatic mitochondria in rats given PTU+T3 were significantly lower than in rats given PTU alone. Ornithine transport was significantly inhibited by the addition of lysine specifically. This response was achieved well within the physiological concentration of lysine. Compared with rats given PTU without T3 treatment, the liver concentration of lysine was significantly higher in rats treated with PTU+T3 and control rats. Ornithine transport into hepatic mitochondria was closely correlated with the excretion of urea. The results suggest that the greater ornithine transport in the hypothyroid (PTU alone) rats is likely to stimulate urea synthesis. A thyroid hor-mone-induced increase in lysine concentration may be at least partly responsible for the changes in ornithine transport into mitochondria.View full abstractDownload PDF (1088K) -
Yoichi FUKUSHIMA, Kyosuke IWAMOTO, Ayako TAKEUCHI-NAKASHIMA, Noriko AK ...1997 Volume 43 Issue 3 Pages 397-411
Published: 1997
Released on J-STAGE: June 15, 2009
JOURNAL FREE ACCESSWe studied the preventive effect against allergies in infants who and whose mothers consumed hypoallergenic formulas until 6 months after birth. Mother and infant pairs were divided into three groups, and the infants were monitored for the development of allergies for the first 2 years. In the MD group (n=102; n=number of infants), the mothers were given a hypoallergenic formula for mothers (MOM HA), which contained hydrolyzed whey protein as the only protein source, as a substitution for cow's milk during late pregnancy and lactation. In the CD group (n=127), the mothers were given cow's milk during the corresponding period. All infants in the MD and CD groups were exclusively breast-fed or mixed-fed with breast milk and hypoaller-genic infant formula (NAN HA), which contains the same hydrolyzed protein as MOM HA. In the AF group (n=54), the mothers consumed MOM HA and their infants were mixed-fed with breast milk and a cow's milk-based adopted infant formula during the corresponding period. In the MD group, no infants were positive to cow's milk-specific im-munoglobulin E (BAST) at 4 months of age, in contrast to 6% and 3% of infants in the CD and AF groups, respectively. The infants in the MD group showed low incidence of various allergies, especially of eczema, as compared to the CD and AF groups. These results suggest that consump-tion of cow's milk by mothers and cow's milk-based formula feeding to infants elevate the risk of allergies in infants, and that consumption of hypoallergenic formula for pregnant and lactating women and for infants could be helpful in preventing allergy development in infants.View full abstractDownload PDF (1636K) -
Naoko KOMENAMI, Masamitsu MIYOSHI1997 Volume 43 Issue 3 Pages 413-418
Published: 1997
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSThis paper provides a procedure for estimating the maximal stationary metabolic rate (SMRmax) in free-moving rats. The SMRmax was estimated by simultaneously comparing energy expenditure with motor activity measured at 10 min intervals for 24 h. The SMRmax was close to but naturally higher than the resting metabolic rates determined by other conventional methods. The coefficient of variation for 3 con-secutive days was below 3%. The ratio of SMRmax to daily minimum energy expenditure was 1.25 in young rats and 1.19 in adult rats. SMRmax is a useful key parameter for analyzing daily energy expenditure and behavior.View full abstractDownload PDF (677K) -
Akimasa NAKASHIMA1997 Volume 43 Issue 3 Pages 419-424
Published: 1997
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSThe stimulatory effect of phytin added to skim milk on acid production by Lactobacillus casei was examined. Phytin stimulated acid production by L. casei fairly well. The stimulatory effect of phytin on acid production was not shown when phytin was treated with Dowex 50 (H+) and neutralized by NaOH solution. The incinerated product of phytin maintained almost equal stimulatory effect on acid production as that before processing. The addition of Mn2+ in the amount contained in a reagent phytin augmented the stimulatory effect on acid production markedly. The further addition of Fe3+, Ca2+, Mg2+ and PO43- in amounts corresponding to their contents in the preparation of phytin as well as Mn2+ increased the effect slightly. The four preparations of phytin contained 0.045-0.20% of Mn, and the greater the Mn content was, the greater the potentiation of acid production.View full abstractDownload PDF (677K)
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