Chicken breast extract (CBEX) containing large amounts of anserine and carnosine-dipeptides containing histidine-was prepared from chicken breast meat. After force feeding of CBEX to mice, anserine and carnosine were absorbed into the blood, and their concentrations reached peaks at 30min after feeding. Additionally, significant increases in the concentrations of anserine and carnosine were evident in the quadriceps femoris of mice after 11 days of the CBEX diet regime. Six days after the start of feeding, mice given the CBEX diet showed a significantly longer swimming endurance time until complete exhaustion in an adjustable-current pool with a fast water current (10L/min), compared with mice fed a control diet (containing 2% casein). These results suggest that one factor responsible for the higher swimming endurance is accumulation, via the bloodstream, of dipeptides from the CBEX diet that increase the biological buffering capacity of skeletal muscles.

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‘Bonito bouillon’ is one of the characteristic seasonings of Japanese food. In this study, we investigated the effects of a high-carbohydrate diet flavored with bonito bouillon (BF diet) on the subject's preference for a high-fat diet (HF diet). Diet preference experiments that compared BF diets and high-carbohydrate (HC) diets of 5-week-old male ICR mice over 24h showed that the BF diet was preferred to the HC diet, implying that bonito bouillon flavor enhanced the preference of the mice for the HC diet. In long-term diet preference experiments, one group of mice (HC & HF) was given free access to the HC and HF diets, and the other group (BF & HF) to the BF and HF diets, for 5 weeks. Intake of the HF diet by the BF & HF group was lower than that of the HC & HF group. Therefore, bonito bouillon flavoring enhanced the intake of the high-carbohydrate diet, thereby decreasing the intake of the high-fat diet.

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We investigated whether coffee and its components (caffeine and chlorogenic acid) reduce stress in rats. In vivo microdialysis was used to characterize the effects of coffee, stress, and their interaction on the serotonergic and dopaminergic systems. Immobilization of the rats for 100min markedly increased the hippocampal levels of dopamine (DA) and serotonin (5-HT). Thereafter, 100min of rest restored the levels of DA and 5-HT to basal values. Treatment with 33mg/kg instant coffee (equivalent to the amount contained in one cup of coffee) or 1.7mg/kg caffeine (equivalent to one cup of coffee) reduced the second restraint-induced increase of the neurotransmitters, especially 5-HT. On the other hand, neither saline nor 1.7mg/kg chlorogenic acid (equivalent to one cup of coffee) reduced the increases. These results suggest that coffee administration helps to relax rats subjected to restraint-induced stress, and that this effect could be due to caffeine. Taken together, these findings suggest that coffee has a modulating effect on the stress response in rats.

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The urea (U) /creatinine (C) ratio was measured in single urine samples. The mean U/C ratios in healthy individuals aged 3 to 7 years and 11 to 12 years were 36.1 for males and 36.0 for females, and 22.1 for males and 19.2 for females, respectively. Those in individuals aged 14 to 15 years, 19 to 23 years, 21 to 60 years, and 61 to 94 years were all between 15 and 18. The U/C ratios in patients aged 59 to 87 years in geriatric wards were 15.3 for males and 16.3 for females. In tube-fed patients supplied with 1, 200 or 2, 400kcal/day, the ratios were below 14 in cases where the amount of absorbed amino acids was less than 42.5g/day, but were above 18 in cases exceeding 52g/day.

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A questionnaire survey was conducted to investigate the relationship between dietary supplement use and health-related behavior of 301 female college students. Fifty-four percent of the subjects claimed to use dietary supplements. Some differences in health-related behavior were found between the group using dietary supplements and the group that did not. The group that did showed a greater tendency to read magazines on health, to have nonspecific complaints, and to consume retort food and the daily dish than the group that did not. Although there was no difference in BMI between the groups, many of the subjects in the supplement group dieted and were interested in fashion trends. There was also considerable use of health drinks by the supplement group. The results suggest that individuals who read health magazines and have nonspecific complaints are more aware about deficiencies in nutritional elements, and therefore tend to use diet supplements more frequently. It is considered that guidance about the significance of nutritional elements obtained from meals and the appropriate use of supplements is important.

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Effects of various dietary factors on the activity and gene expression of hepatic enzymes in fatty acid synthesis and oxidation were examined in the rat. Dietary soybean phospholipid profoundly decreased hepatic triacylglycerol synthesis accompanying by a marked reduction in the activity and mRNA levels of enzymes involved in fatty acid synthesis. Phospholipids from egg yolk and safflower seed origin showed similar physiological activity in reducing hepatic lipogenesis. Dietary fats rich in α-linolenic acid compared to saturated fats and a fat rich in linoleic acid increased the activity and gene expression of hepatic enzymes in fatty acid oxidation. The β-oxidation rate of α-linolenic acid, relative to palmitic and linoleic acids, was higher in both the mitochondrial and peroxisomal pathways. It was suggested that both substrate specificity and alterations in the activities of the enzymes in the β-oxidation pathway play a significant role in regulating serum lipid concentrations in rats fed α-linolenic acid. Sesamin, a sesame lignan, was found to be a potent inducer of hepatic fatty acid oxidation. Sesamin dose-dependently and profoundly increased the activity and gene expression of hepatic fatty acid oxidation enzymes. Sesamin also showed the physiological activity in reducing gene expression of hepatic lipogenic enzymes through the down-regulation of sterol element binding protein-1. Therefore, it is apparent that dietary sesamin reduces serum lipid levels through alterations in both hepatic fatty acid oxidation and synthesis.

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Intracerebroventricular administration of the high-molecular-mass fraction of cerebrospinal fluid (CSF) from exercise-exhausted rats to sedentary mice produced a decrease in spontaneous motor activity, whereas CSF from sedentary rats had no such effect. This suggests the presence of a substance regulating the urge for motion as a response to fatigue. A bioassay system using Hydra, a freshwater coelenterate, showed an activity indistinguishable from transforming growth factor beta (TGF-β) in the CSF from exercise fatigued rats, whereas no such activity was present in CSF from sedentary rats. The increase in the concentration of active TGF-β in the CSF from exercise-fatigued rats was also ascertained by another bioassay system using mink lung epithelial cells (Mv1Lu). Injection of TGF-β into the brains of sedentary mice elicited a similar decrease in spontaneous motor activity in a dose-dependent manner. Increasing the exercise load on rats raised both the level of active TGF-β in their CSF and the depressive effect it elicited on the spontaneous motor activity of mice. Taken together, these results suggest that exercise increases the level of active TGF-β in the brain, which creates a feeling of fatigue and thus suppresses spontaneous motor activity.

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Degenerative effects on lymphoid tissues such as the thymus and Peyer's patches were observed in mice after oral administration of methyl linoleate hydroperoxide, a model of primary autoxidation products of oils, or low-molecular-weight compounds: one type of secondary autoxidation product. Immunocompetent cells such as thymus and spleen cells were modulated by feeding the mice with partially oxidized soybean oil (peroxide value, 150meq/kg) for 3 months. To evaluate the effect of in vivo lipid peroxidation on immunocompetent cells, mice were fed for 30 days on seven different dietary oils including fish oil rich in n-3 polyunsaturated fatty acids. The fish oil diet induced modulation of spleen cells and a significant increase of membranous lipid hydroperoxide (hydroperoxides of phosphatidylcholine and phosphatidylethanolamine) accumulation as a marker of oxidative senescence in red blood cells. These results suggest that dietary oxidized oils (exogenous lipid peroxides) and endogenous lipid peroxides formed in the body of animals can affect immunocompetent cells and also immune responses.

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