• Journal of Nutrition and Health
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• v.34 no.4
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• pp.359-366
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• 2001

Studies were carried out to explore the influence of dietary protein level on bone metabolism in uninephrectomized rat (experimental renal failure model) when dietary Ca and P contents were equal. Male rats were uninephrectomized or sham operated and fed 8%, 15% and 40% casein diets for 24 weeks. Ca and P contents of the all diet were 0.4% and 0.6% respectively. The results are summarized as follows. We did not found any significant difference in PTH and Ca level of the serum, Ca intake and Ca excretion among the experimental groups. There was significant positive correlation between the PTH and phosphate level. There was significant inverse correlation between serum Ca and creatinine level. The effect of the dietary protein level and renal mass loss on density and Ca contents of the bone were small and different according to the kinds of the bone. Low protein diet was associated with a significant enhancement of scapular density. Femur and vertebra density, however, were not influenced by dietary protein level and uninephrectomy. Light microscopic examination showed several calcified foci in the kidney in all experimental groups. Low protein diets have been used for a long time in the conservative management of chronic renal failure as they have a beneficial effect in preventing the appearance of symptoms. This study elucidated that part of beneficial effects of the low protein diet related to the suppression of the hyperphosphatemia. And these results, even though uninephrectomized rats fed high protein diet, the secondary hyperparathyroidism is supressed by the regulation of the P level. Therefore this study emphasized the need to pay more attention to the regulation of dietary P level as well as dietary protein content in chronic renal failure. (Korean J Nutrition 34(4): 359∼366, 2001)

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.3
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• pp.677-684
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• 1999

This study has dealt the effect of Ca regulating hormones and dietary Ca levels on Ca metabolism. Animals(BALB/c mice) were divided into three dietary groups(high and medium Ca and Ca free) and hormones including parathyroid hormone(PTH), calcitonin(CT), cholecalciferol(Vit D) were i.p. injected. After feeding experimental diets for five weeks, mice were anaethetized and sacrificed by heart puncture. We found that femur growth of mouse was slightly increased by high dietary Ca without showing statistical significance comparing to low dietary Ca group. The combination of PTH and CT showed the same effect when dietary Ca was high. At the same time, total mineral retention in bone was most affected by dietary Ca. In general, high Ca diet elevated Ca level in the serum. When dietary Ca was low, PTH stimulated Ca release from the bone into the serum, which was shown to be inhibited by CT treatment. Comparing to the control, PTH, Vit D and CT together tended to inhibit serum Ca level at high and medium dietary Ca. PTH and Vit D inhibited Ca reserve in the liver at all dietary levels of Ca. Both PTH and Vit D stimulated bone Ca retention when dietary Ca was low, but this effect was reversed when dietary Ca was high. When PTH, Vit D and CT were administered together, bone Ca level was greatly enhanced at low dietary Ca than at high dietary Ca, which suggests that these hormonal cooperation is needed for proper bone density maintenance especially when dietary minerals are not sufficient.

• YAKHAK HOEJI
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• v.38 no.1
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• pp.57-66
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• 1994

We studied the effect of eicosanoids on the content of energy metabolites and the intrasynaptosomal $Ca^{++}([Ca^{++}]_i)$ concentration in cerebral ischemic rats. An ischemic model was made by bilateral carotid artery ligation (BCAL) and by incubation of synaptosomes under aglycemic and $N_2$ gas bubbling condition. The content of ATP, creatine phosphate and glucose decreased at 15 minutes after BCAL while that of lactate increased in male Wistar rats. Oral administration of EPA(100 mg/ml/Kg/day) or DHA(16 mg/ml/Kg/day) for 6 weeks improved both the decreases and the increase of the cerebral energy metabolites. In addition, the increase of $[Ca^{++}]_i$, under BACL was suppressed by EPA or DHA treatment. When the both Wistar rats and SHR were administered orally with EPA or DHA for 6 weeks, the effect on the increase of $[Ca^{++}]_i$ under ischemia by $N_2$ gas bubbling were protected. From these results, it may be that EPA or DHA treatment were greatly contributed to preservation of ischemic cerebral energy metabolism and $Ca^{++}$ concentration.

• Horticultural Science & Technology
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• v.33 no.4
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• pp.525-534
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• 2015

The effects of aqueous calcium oxide (CaO) treatment on the quality characteristics and shelf life of mulberry (Morus alba L.) were investigated. Mulberry fruits were immersed in 0, 0.5, 1, and $2g{\cdot}L^{-1}$ CaO solutions for 0, 1, 3, 6, and 12 min. Mulberries were then rinsed with potable tap water for 1 min and stored at $-1^{\circ}C$ for 14 days. CaO treatment was effective at promoting the retention of titratable acid, pH, and ascorbic acid as well as total flavonoid contents. CaO concentration and treatment time were significant factors affecting the sensory qualities of the fruits, including off-odor, flavor, and texture. For shelf life determinations, the total bacterial count was reduced by CaO treatment so that the samples treated with $1g{\cdot}L^{-1}$ CaO for 12 min had bacterial levels at 14 days comparable to those of the control at 4 day, and no coliform group was detected after CaO treatment. These results indicate that calcium oxide treatment is a promising approach for the preservation of mulberry fruit.

• Journal of Nutrition and Health
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• v.19 no.1
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• pp.66-73
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• 1986

This study was undertaken to investigate the effects of age and of the dietary protein sources & levels on urinary calcium excretion and bone metabolism in the rats. Two experiments were conducted . In experiment U, 6& 20 weeks old rats were fed 8 & 36%, casein & ffish protein diet for 5 weeks . In experiment II, 16& 52 weeks old rats were fed 40 % protein diets, protein sources were casein, fish and gluten. High-protein diet group excreted more caldium in urine than low-protein group. Urinary calcium excretion was affected by the sources of protein ; gluten group excreted more Ca, followed by fish & casein group. Total bone Ca & Ca proportion in ash were higher in 20 weeks old rats than 6 weeks old rats, but 16 & 52 weeks old rats showed no differences. bone composition showed that water proportion was high and ash proportion was low in 6 weeks old rats than in 20 weeks old rats. However, these tendencies were not observed between 16 weeks and 52 weeks old rats. And bone composition was affected by protein sources ; higher ash proportions were noted in one order of casein, fish, and gluten water proportion were lower in one same order.

• Journal of Nutrition and Health
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• v.24 no.2
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• pp.114-123
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• 1991

This study was designed to investigate the effects of aerobic dancing and/or Ca supplemen-tation for six months on Ca metabolism in postmenopausal women. The subjects were healthy 29 women aged from 60 to 70 years old. They were divided into four groups ; placebo and Ca supplementation group with and without exercise. The amount of Ca supplemented was 500mg a day. The frequency of doing exercise was three times a week and it took 40 minutes to complete once all the course of aerobic dancing programmed for old women. The results were summarized as follows : 1) Bone density of the second lumbar spine and ward's triangle measured after experiment decreased significantly in control group as compared with pre-experimental level(P<0.05). On the contrary it showed a tendency to increase or maintained the pre-experimental level after experiment in other groups. 2) Urinary Ca/creatinine and P/creatinine ratios did not show any significant differences among groups before and after experiment. But urinary Ca/creatinine ration decreased signifi-cantly in Ca group after experiment(P<0.05) 3) Serum Ca and P levels did not show any significant differences among groups before and after experiment. But serum Ca level in creased significantly in Ca group after experiment(P<0.05) 3) Serum Ca and P levels did not show any significant differences among groups before and after experiment. But serum Ca level increased significantly in Ca group after experiment (P<0.05). 4) Serum PTH level also did not show any significant differences among groups before and after experiment. But serum calcitonin level decreased significantly in Ca group after experiment(P<0.05). The above results showed that it will be difficult to prevent degenerative bone loss without regular exercise and/or Ca supplementation in postmenopausal women having Korean usual diets.

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.3
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• pp.259-260
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• 1989

• Journal of Nutrition and Health
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• v.44 no.2
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• pp.101-111
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• 2011

It is controversial whether low calcium intake, commonly associated with osteoporosis, results in calcium accumulation in soft tissues. This study was conducted to investigate the effects of low calcium (Ca) and oxalate (ox) intake on soft-tissue Ca deposits and bone metabolism in ovariectomized (ovx) rats. Eight week old female Sprague-Dawley rats were ovariectomized and divided into four groups. The rats were fed experimental diets containing low (0.1%, w/w) or normal (0.5%, w/w) Ca with or without sodium oxalate (1%, w/w); Sham/NCa, Ovx/NCa, Ovx/LCa, Ovx/NCa-ox, Ovx/LCa-ox for 6 weeks. All ovx rats showed a remarkable increase in body and tissue weight, glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, blood urea nitrogen, alkaline phosphatase, and decreases in weight, ash, and Ca contents, as well as bone breaking force compared to those in sham rats. Serum Ca concentration was not significantly affected by dietary Ca levels or ox intake. Kidney Ca, ox acid content, and microscopic Ca deposition increased remarkably in the Ovx/LCa-ox group compared to those in the other groups. Ca content in the spleen and aorta also increased significantly, but the weight contents, Ca, bone breaking force, and Ca and oxalic acid in feces decreased significantly in the Ovx/LCa-ox group. Serum parathyroid hormone levels were not significantly different among the groups. These results indicate that low Ca intake decreased bone mineral content and increased Ca deposits in soft tissues, which was aggravated by ox intake in ovx rats. Thus, high ox intake may result in a kidney disorder in patients with osteoporosis who eat a low Ca diet.

• Exercise Science
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• v.26 no.3
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• pp.229-237
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• 2017

PURPOSE: This study was to investigate the Glycolysis mediated sarcoplasmic reticulum (SR) $Ca^{2+}$ signal regulates mitochondria $Ca^{2+}$ during skeletal muscle contraction by using glycolysis inhibitor. METHODS: To examine the effect of Glycolysis inhibitor on SR and mitochondria $Ca^{2+}$ content, we used skeletal muscle fiber from gastrocnemius muscle. 2-deoxy glucose and 3-bromo pyruvate used as glycolysis inhibitor, it applied to electrically stimulated muscle contraction experiment. Intracellular $Ca^{2+}$ content, SR, mitochondria $Ca^{2+}$ level and mitochondria membrane potential (MMP) was detected by confocal microscope. Mitochondrial energy metabolism related enzyme, citric acid synthase activity also examined for mitochondrial function during the muscle contraction. RESULTS: Treatment of 2-DG and 3BP decreased the muscle contraction induced SR $Ca^{2+}$ increase however the mitochondria $Ca^{2+}$ level was increased by treatment of inhibitors and showed and overloading as compared with the control group. Glycolysis inhibitor and thapsigargin treatment showed a significant decrease in MPP of skeletal muscle cells compared to the control group. CS activity significantly decreased after pretreatment of glycolysis inhibitor during skeletal muscle contraction. These results suggest that regulation of mitochondrial $Ca^{2+}$ levels by glycolysis is an important factor in mitochondrial energy production during skeletal muscle contraction CONCLUSIONS: These results suggest that mitochondria $Ca^{2+}$ level can be regulated by SR $Ca^{2+}$ level and glycolytic regulation of intraocular $Ca^{2+}$ signal play pivotal role in regulation of mitochondria energy metabolism during the muscle contraction.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.6
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• pp.774-781
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• 2012

This study investigated dose-response effects of chlorogenic acid (CA) on glucose metabolism and the antioxidant system in streptozotocin (STZ)-induced diabetic mice with a high-fat diet (HFD). Male ICR mice were fed with a HFD (37% calories from fat) for 4 weeks prior to intraperitoneal injection with STZ (100 mg/kg body weight). Diabetic mice were supplemented with two doses of CA (0.02% and 0.05%, wt/wt) for 6 weeks. Both doses of CA significantly improved fasting blood glucose level, glucose tolerance and insulin tolerance without any changes in plasma insulin and C-peptide levels. Plasma leptin concentration was significantly higher in the CA-supplemented groups than in the diabetic control group. Both doses of CA significantly increased hepatic glucokinase activity and decreased glucose-6-phosphatase activity compared to the diabetic control group. The ratio of glucokinase/glucose-6-phosphatase was dose-independently higher in CA-supplemented mice than in diabetic control mice. CA supplementation dose-independently elevated superoxide dismutase and catalase activities, whereas it lowered lipid peroxide levels compared to the diabetic control mice in the liver and erythrocyte. These results suggest that low-dose CA may be used as a hypoglycemic agent in a high-fat diet and STZ-induced diabetic mice.