Changes in growth, nitrogen balance and glucose metabolism were investigated in rats given a high-phosphorus (P) diet for 3 weeks. Eighteen rats were divided into 3 groups: the first group (NF) was fed a normal P diet (0.5% P) freely, the second group (HF) was fed a high-P diet (1.5% P) freely, and the third group (NR) was fed a normal P diet, being restricted to the same amount of food consumed by the rats given the high-P diet. Nitrogen retention was decreased in the rats fed the high-P diet compared with the rats fed the normal P diet. Excretion of urinary 3-methylhistidine in the rats fed the high-P diet was higher than that in the rats pair-fed the normal P diet. The concentration of serum glucose in the rats fed the high-P diet was higher than that in the rats pair-fed the normal P diet. Content of liver glycogen in the rats fed the high-P diet were detected. The activity of liver glucose-6-phosphatase [EC 3.1.3.9] was decreased in the rats fed the high-P diet compared with those fed the normal P diet. These results indicate that rats fed a high-P diet utilize not only glucose and fatty acid but also protein as an energy source.

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The effects of various dietary oils and egg yolk phospholipids on the concentration of serum lipid and accumulation of pentachlorobenzene (PECB) in rat tissues were examined. The experimental diets contained 0.1% PECB and 10% olive oil, safflower oil or docosahexaenoic acid concentrate. Diets in which half of each experimental oil diet was substituted with egg yolk phospholipid were also prepared. After the diets had been administered for two weeks, the concentration of serum lipid, the PECB concentration in serum and tissue, and fecal apparent excretory ratio of PECB were determined. The major results were as follows: 1) The serum total cholesterol and triglyceride concentrations decreased in order olive oil>safflower oil> docosahexaenoic acid concentrate. When half of the olive oil or safflower oil was substituted with the egg yolk phospholipid, the serum lipid levels in the animals given these diets, but not the docosahexaenoic acid concentrate, decreased significantly. 2) The PECB concentrations in the liver and epididymal fat pad decreased in the order olive oil>safflower oil>docosahexaenoic acid concentrate. The PECB accumulation in these tissues was significantly suppressed when half of the olive oil and safflower oil, but not docosahexaenoic acid concentrate, was substituted with the egg yolk phospholipid. 3) The fecal apparent excretory ratio of PECB was similar among the dietary groups. The activities of the liver drug-metabolizing enzyme P-450 and serum GOT or GPT did not differ among the dietary groups. These results suggest that the PECB accumulation in rat tissues is suppressed by highly unsaturated fatty acid and egg yolk phospholipids in the diet. The changes in the levels of serum lipids and the concentration of tissue PECB in rats showed a strong positive correlation with dietary lipids.

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Calcium (Ca) absorption from milk, fish and vegetables in nine healthy Japanese young women was measured by the balance method by carrying out a study three times during the proliferative phase of the menstrual cycle. Each study lasted for seven days; the subjects were given a basal diet containing 200mg Ca for three days, following by the basal diet with additional milk or fish (pond smelt, sardine) or vegetables (komatsuna-green, Jew's marrow, saltwort) containing 400mg Ca for the remaining four days. During the study period, feces and urine were sampled daily, and blood was sampled on days 1, 4 and 8. The Ca content of the basal diet, milk, fish, vegetables, feces and urine was measured by atomic absorption spectrophotometry, and Ca balance was compared among milk, fish and vegetables. Ca balance during the basal diet period was negative, but turned positive during the last four days when the diets supplemented with milk, fish or vegetables were taken. Apparent Ca absorption from milk was 39.8%, that from fish 32.9% and that from vegetables 19.2%. During the entire study period, no fluctuations were observed in serum Ca, parathyroid hormone or calcitonin, but the serum 1-25 (OH)₂ cholecalciferol level was high during the period when the low calcium basal diet was taken.

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In order to evaluate the risk factors associated with coronary heart disease in patients with eating disorders, serum total cholesterol (TC), HDL-cholesterol, triglyceride, phospholipid (PL) and apolipoproteins were measured in 37 restricting anorectic (AN), 17 anorectic-bulimic (AB) and 34 nonanorectic-bulimic (BN) patients and 21 control (C) subjects. Serum TC, PL, apolipoprotein (apo) B, apo C-II, apo C-III and apo E levels in AN, AB and BN were all significantly higher than those in C. TC was negatively correlated with % body weight in AN and AB, negatively correlated with T₃ levels in AN, and positively correlated with the grade of bulimia in BN. These results suggest the presence of hypercholesterolemia in patients with bulimia nervosa as well as those with anorexia nervosa, and that the pathogenesis of hypercholesterolemia differs between these two subgroups of eating disorders.

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To elucidate the hypocholesterolemic mechanism of Kabosu juice residue (an ethanol-precipitated fraction of Kabosu juice: KJR), we investigated the effects of KJR on lipid metabolism in the serum and liver using male stroke-prone spontaneously hypertensive rats (SHRSP) as an animal model. Six rats, 7 weeks of age, were fed on a high-cholesterol diet containing KJR for 2 weeks. The increase in serum total cholesterol was markedly suppressed in comparison with the control group (N=6), due to suppression of increases in the very-low-density lipoprotein and low-density lipoprotein fractions. The concentration of serum apolipoprotein (apo) A-I was significantly decreased and that of serum apoA-IV was significantly increased, while no change was observed in the lipid content of the high-density lipoprotein (HDL) fraction, suggesting an alteration of HDL composition. In the liver, increases in the contents of cholesterol and triglyceride were markedly suppressed. In addition, the activities of cholesterol 7α-hydroxylase [EC 1.14. 13. 17] and acyl-CoA: cholesterol acyltransferase [EC 2.3. 1.26] were significantly low.

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Salacia reticulata is a plant commonly used in Sri Lanka for the prevention of hyperglycemia. The inhibitory effects of an aqueous extract from the stem of Salacia reticulata Wight (SRE) (Celastraceae) on postprandial hyperglycemia in rats and humans were investigated. SRE dose-dependently suppressed elevation of the serum glucose level induced by sucrose, maltose and α-starch, but not by glucose or lactose. The suppressive effect of SRE was more potent against sucrose-induced hyperglycemia than against hyperglycemia induced by the other sugars. In addition, we investigated the effects of SRE on activities of various glucosidases and α-amylase. The results showed that SRE strongly inhibited the activities of α-glucosidases prepared from yeast and rat jejunum (IC₅₀: 5 and 8μg/mL, respectively). SRE also inhibited the activity of α-amylase (IC₅₀: 35μg/mL), but not that of β-glucosidase. The relative inhibitory effects of SRE against partially purified α-glucosidases from rat jejunum showed the order: sucrase=isomaltase (IC₅₀: 15μg/mL, respectively)>maltase (IC₅₀: 701μg/mL). Moreover, in a sucrose tolerance test performed on human volunteers, 5min pretreatment with SRE (200mg) prior to sucrose (50g) loading significantly suppressed postprandial hyperglycemia. These results demonstrate that, based on its inhibition of α-glucosidases and α-amylase, SRE has anti-hyperglycemic activity, and may be a useful natural material for the prevention and therapy of diabetes.

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Changes in the tissue contents of several nutrients with age have been reported in the Senescence Accelerated Mouse (SAM). In this study, the effect of aging on the status of thiamine in tissues of SAM mice was studied. Both males and females of both SAMP1 and SAMR1 fed a commercial diet were used for the study. Thiamine contents were measured in the liver, brain, kidney, heart and skeletal muscle in these mice at the ages of 2, 6 and 10 months. In the kidney, the thiamine content in SAMP1 was lower than that in SAMR1 at each respective age in both males and females. However, in the heart and muscle, the thiamine content in SAMP1 was higher than that in SAMR1 at each respective age in both males and females. The heart thiamine content of male SAMP1 decreased significantly with age. These results suggest that genetic factors are related to the age-associated changes in tissue thiamine levels.

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