• Journal of Nutrition and Health
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• v.28 no.8
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• pp.737-748
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• 1995

Osteoblast(OBL) cells were isolated from ICR Swiss neonatal mouse calvarial tissues and cultured in a CO2 incubator with minimum essential medium (MEM) containing 0.25g BSA. The cells were cultured for 7 days and were treated with bovine parathyroid hormone (bPTH, 1-34) and calcitonin(CT). Enzyme activities related to mineral metabolism and other biochemical actions within the bone cells including protein phosphorylation were investigated. In other experiments using cultured calvarial bone tissues, hormones were treated for 24, 48, 72 or 96 hours. The activities of $\beta$-glucuronidase enzymes involved in bone collagen synthesis and mineral deposits were increased by 8% with bPTH and were inhibited with CT treatment, while those were 67% increase treated with bPTH and CT together. On the other hand, alkaline phophatase(AP) activities were inhibited by PTH hormone at all the time courses observed. Protein phosphorylation reaction in OBL was mediated by bPTH, cAMP and ionized Ca. Phosphorylation was observed in different cell fractions including homogenate, membrane and cytosol. The number of proteins phosphorylated by PTH, cAMP, and Ca were 10, 5, and 9, respectively. Most of the protein kinases(PKs) were existed in cytosolic compartment. In membrane fractions, two bPTH-dependent-PKs (70K, 50K Da) were observed of which 70K Da protein was also Ca-dependent. Most of the cAMP-dependent PKs were regulated via bPTH. 70K, 50K, 5K, 19K, 16K, 10.5K phosphoproteins regulated by Ca share the same pathways as those by bPTH-dependent proteins. Ca seems to regulate PK activities differently from cAMP.

• Journal of Nutrition and Health
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• v.43 no.4
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• pp.351-356
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• 2010

This study was done to evaluate the effect of Ca source using fish (Tilapia mossambica) scales on the bone metabolism. Male Sprague-Dawley rats, 4 weeks of age, were fed low-calcium diet (0.15% Ca) for 2 weeks. The rats on the low-calcium diet were further assigned to one of following three groups for an additional 4 weeks: 1) Ca-depletion group (LoCa) given 0.15% Ca diet ($CaCO_3$), 2) Ca-repletion group (AdCa) given 0.5% Ca diet ($CaCO_3$), 3) Ca-repletion diet (AdFa) received 0.5% Ca diet (Ca source from Tilapia mossambica scales). Serum parathyroid (PTH) and calcitonin showed no differences among experimental groups. Whereas LoCa group elevated the turnover markers, serum ALP and osteocalcin, and urinary deoxypyridinoline (DPD), AdCa and AdFa groups reduced their values. Elevation in the femoral weight, ash and Ca contents was observed in AdCa and AdFa groups. Bone mineral density was increased in AdCa and AdFa groups by 25-26% compared with LoCa group. These data demonstrate that Ca repletion with either Ca source from Tilapia mossambica scales or $CaCO_3$ is similarly effective in the improvement of bone turnover markers and BMD, suggesting the usefulness of Tilapia mossambica scales in the prevention of bone loss compared with $CaCO_3$.

• 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.

• Journal of Nutrition and Health
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• v.20 no.2
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• pp.135-144
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• 1987

This study was carried out to investigate the effect of dietray carbohydrate level on the lipid and Ca metabolism, and on immune response in the process of aging. Sprag\ulcornerue - Dawley male rats of 12 months of age were fed either high carbohydrate or low carbohydrate diet for 9 months. With increasing age from 12 months to 21 months, there was no significant increase in body weight, however, the epididymal fat pat weight and total serum lipid tend to become higher, and the inorganic/organic matterratio in bone tends to become lower. This suggests that body fat accumulation increase and bone mass decrease with age. Rats fed low carbohydrate diet showed the higher epididymal fat pat weight, and the lower Ca content in femur and scapular compared to high carbohydrate diet fed rats. The immune response was also lower in low carbohydrate diet group judged by the lower thymus and spleen index and by the lower response to PHA and ConA stimulation. The results of this study suggests that the dietary level of carbohydrate and fat may play an important role in the process of aging. It could be recommended to practice high carbohydrate -low fat diet for the elderly to reduce the risk of degenerative diseases.

• Proceedings of the KSCN Conference
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• 1999.05a
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• pp.114-114
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• 1999

• Journal of the East Asian Society of Dietary Life
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• v.17 no.1
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• pp.1-10
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• 2007

The effects of mulberry-leaf powder Tofu(MPT) on anthropometric measurements, including bone mineral density(BMD) in the right carpus, biochemical bone turnover markers, serum levels of lipids and macrominerals, were investigated in 30 smoking male adults who lived in Choongnam were given MPT(100 g/day) for 4 weeks. The average ages, number of smoked cigarettes and packyear were 22.38 years, 15.12/day and 3.54 years, respectively. The nutrient contents per 100 g MPT were 86.10 kcal energy, 8.98 g protein, 0.53 mg fiber, 211.33 mg Ca and 1.59 g fat. Anthropometric measurements, including dietary intake using the 24-hours recall method, carpal BMD using DEXA, serum levels of protein, albumin and glucose, lipid profiles (cholesterol, triglyceride, HDL-cholesterol, LDL-cholesterol) with Al(atherosclerosis index), HTR, CRF, LHBt, some biomarkers of BMD(serum alkaline phosphatase activity, osteocalcin, urinary DPD), and serum macrominerals(Ca, Ca/P ratio, Mg) and Pb were analyzed before and after consumption of MPT. After MPT consumption, dietary intakes of plant protein, total Ca and plant Ca increased significantly, but there were no significant differences in anthropometric measurements, BMD with bone metabolism markers, serum levels of protein, albumin or glucose, lipid profiles with AI, HTR, LHR and CRF.

• Journal of Nutrition and Health
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• v.21 no.1
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• pp.23-35
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• 1988

This study was designed to find out the effects of aerobic exercise on lipid and Ca metabolism in seven healthy college women, aged 20 to 22 years. Metabolic studies were conducted before and after a 10-weeks exercise period, during which subjects participated in the planned aerobic dance program every day except Sunday. The initial mean time engaged in the exercise was 28 minutes and it was gradually increased up to 45 minutes around the middle point of the exercise period. During both of metabolic study periods, the subjects ate experimental diets which supplied about 120g of protein and 600mg of Ca daily and during the rest of the experimental period they ate their usual diets. The use of alcoholic beverages and drugs were prohibited. The results were summarized as follows. 1) The effect of exercise on lipid metabolism. (1) Mean body weight decreased significantly after exercise(p<0.01) and it did not show a significant decline in skinfold thickness and total body fat contents. (2) Serum total cholesterol level decreased significantly after exercise(p<0.05) and TG level also tended to be lower than that of pre-exercise period. Exercise did not exert any influence on the level of serum HDL-cholesterol in this study. (3) Exercise did not alter total lipid content in feces and apparent lipid absorption rate. 2) The effect of exercise on Ca and P metabolism. (1) After exercise, focal Ca excretion was slightly reduced, however, urinary Ca excretion was not significantly changed. In the results, a slight increase was shown in body Ca retention after exercise. (2) Exercise tended to increase urinary P excretion, but neither P balance nor fecal excretion was significantly changed after exercise. (3) Bone mineral content was not affected by exercise. In summary, aerobic exercise decreased total cholesterol and TG level in serum and tended to increase body Ca retention. With the results, it can be concluded that the additional physical activities beyond the normal daily life in college women might prevent some degenerative diseases-suchas atherosclerosis and osteoporosis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.6
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• pp.958-964
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• 2004

This study examined the effects of maternal calcium intake levels on mineral metabolism during pregnancy and lactation. Five week-old female Sprague-Dawley rats were fed normal Ca (NCa, 0.5%) and low Ca (LCa, 0.15%) diets for 5 weeks during preconception. The low Ca intake group was divided into three groups and fed low Ca (0.15%), normal Ca (0.5%) and high Ca (1.5%) diets for 6 weeks during pregnancy and lactation. All of the rats were mated with normal male rats. The control group was consistently fed a normal Ca diet for 11 weeks. Pups were adjusted to 10 per dam. After weaning, dams and their weaned rats were sacrificed. We measured total protein, albumin, alkaline phosphatase and mineral content in serum and weight, length, breaking force, ash and mineral content in bone and kidney. There was no significant difference in weight gain and food intake among the groups. Serum total protein and albumin were in the normal range but slightly decreased with a low Ca diet during preconception. Calcium supplementation above normal level increased bone weight, Ca content and breaking force in femur of maternal and their weaned rats. However, high maternal Ca intake significantly decreased Mg and Fe contents in maternal serum and bone and Mg and Zn contents in serum of weaned rats. Also, it induced Ca, P and Mg deposit in maternal kidney. Our experimental results suggest that Ca deficiency during preconception may deteriorate bone status of mother and their offsprings. Moreover, high Ca supplementation during pregnancy and lactation may lead to disturb mineral metabolism in bone and other tissues.

• Journal of Nutrition and Health
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• v.28 no.4
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• pp.298-308
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• 1995

To investigate the effect of estrogen and dietary protein level on Ca metabolism, female rats were undergone ovariectomy or sham-operation. Ovariectomized rate were divided into either estrogen-or vehicle-treated groups. Each treatment group was again divided into 40%-casein(H) or 10%-casein(L) diet groups. All experimental diets contained 0.2% Ca, 0.4% P and fed to rats for 8 weeks. Apparant Ca absorption and Ca balance were not affected by dietary protein level and ovariectomy, however they were increased by estrogen injection and this effect was even higher in low protein groups. Urinary Ca excretion were higher in high protein groups. GFR was not affected by dietary protein level, ovariectomy, or by estrogen injection. Urinary protein excretion was higher in high protein groups, which implies that the kidney funtion was deteriorated by high protein diet, and this may account partly for the higher urinary Ca in high protein groups. Ovariectomy or estrogen treatment had no effect on urinary protein excretion. Urinary hydroxyproline was higher in ovariectomized rats and increased in high protein grous. Elevated value of ovarictomized rats was lowered by estrogen injection, especially in low protein group. Alkaline phosphatase tended to increase in ovariectomized groups and lowered with estrogen treatment, but this difference was not statistically significant. Serum PTH was not affected by ovariectomy and dietary protein level. Therefore the increased hydroxproline excretion does not seem to be attributed to PTH. Dietary protein level, ovariectomy and estrogen treatment did not affect the weights and components of femur, scapular, and 4th vertebra. Ash/wt ratio of femur was, however, lower in ovariectomized rats and increased with estrogen treatment. Therefore, among the bones studied, femur seemed to be the most vulnerable. The results of this study shows that estrogen treatment may alleviate or reduce bone loss in postmenopausal women somewhat, especially for those people with low protein diet.

• Korean Journal of Community Nutrition
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• v.6 no.5
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• pp.765-772
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• 2001

To delineate the relationship between the nutrient intake from diet and the serum biochemical markers of bone metabolism, 56 postmenopausal women of 50 to 77 years of age were recruited. The biochemical markers including osteocalcin, calcium, phosphorus, estradiol and free testosterone were measured in fasting blood. Bone mineral density(BMD) was measured also by dual energy X-ray absorptiometry, and the nutrient intake of earth individual subject was estimated by 24-hour recall of 3 days. The age of the subjects was 64.8 $\pm$ 7.7 years, and the BMDs of the subject were 0.86 $\pm$ 0.26g/$cm^2$(Lumbar spine), 0.60 $\pm$ 0.10g/$cm^2$ (Femoral neck), 0.49 $\pm$ 0.10g/$cm^2$(Trochanter), and 0.41 $\pm$ 0.14g/$cm^2$(Ward's triangle). There were no significant differences among age and nutrient intake level groups due to the small sample size. The biochemical markers showed certain degree of relationship with nutrient intake levels. The results were compared among 3 groups with different nutrient intake level classified by the percentage of Recommended Daily Allowances(RDA) for Koreans as follows low < 75% RDA, 75% RDA $\leq$ adequate < 125% RDA, high $\geq$ 125% RDA. The low energy and low riboflavin groups showed significantly higher serum osteocalcin levels than those of the high intake groups(p < 0.05). On the other hand, there was a trend for serum Ca level to be higher with high nutrient intake. In this case, protein and thiamin were the only nutrients that reached a statistical significance(p < 0.05). And the groups with low intake for protein and Ca showed significantly lower serum free testosterone levels than that of other intake groups(p < 0.05). This study suggests an important role of nutrient intake levels on blood biochemical markers of bone metabolism.