• Journal of Nutrition and Health
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• v.27 no.10
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• pp.1025-1036
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• 1994

This study was designed to investigate the effects of Ca and/or vitamin D supplementation for 53 weeks on bone metabolism in postmenopausal women. The subjects were healthy 18 women aged from 59 to 69 years old. They were divided into three groups : placebo, Ca(1000mg/day) supplementation and Ca(1000mg/day) with vitamin D(12.5$\mu\textrm{g}$/day) supplementation. During the experimental periods except for metabolic studies, the subjects ate their usual diets and the use of drugs as well as excessive exercise was prohibited. Metabolic studies were conducted in the 1st week and in the 53rd week of the experimental periods. The subjects ate experimental diets which consisted of 1787.3kcal, 69.6g of protein, 561.5mg of Ca and 1078.6mg of P daily during both of the metabolic study periods. The results were summarized as follows; 1) Bone density of the second lumbar spine and trochanter measured after treatment decreased significantly in control group as compared with pre-experimental level(p<0.05). On the contrary, bone density of femoral neck and Ward's triangle in Ca group and the second lumbar spine in Ca.Vit D group increased significantly after treatment. 2) Serum PTH and calcitonin levels did not show any significant differences among groups before and after treatment. But serum PTH level increased significantly in all groups after treatment(P<0.05). 3) Serum Ca and P levels did not show any significant differences among groups before and after treatment. But serum Ca level increased significantly in all groups after treatment (P<0.05) and serum P level decreased significantly in Ca.Vit D group after treatment(P<0.05). 4) Mean 24-hours fecal Ca excretion of Ca group was the highest in the 1st week of treatment(P<0.01), and that of control group was the lowest in the 53rd week of treatment(P<0.01). Fecal Ca excretion increased significantly in control and Ca.Vit D group in the 53rd week of treatment(P<0.05). Urinary Ca excretion did not show any significant differences among groups in the 1st and 53rd week of treatment, but that of Ca.Vit D group was the highest the 1st week of treatment(P<0.01). In the 53rd week of treatment Ca and Ca.Vit D group showed positive Ca balance, but control group showed negative Ca balance. The above results showed that it will be difficult to prevent degenerative bone loss without Ca and/or vitamin D supplementation in postmenopausal women eating Korean usual diets.

• Journal of Embryo Transfer
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• v.16 no.2
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• pp.79-89
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• 2001

Steroid hormones control the expression of many cellular regulators, and a role thor estrogen in mouse oocytes has been well documented. The preovulatory $E_2$increment is generally accepted as the endocrine process regulating induction of in vivo oocyte maturation To address whether the activity of the T-type $Ca^{2+}$ channel is altered by 17 beta-estradiol ( $E_2$), we examined the actions of $E_2$on the calcium channel of mouse oocytes and early embryos. Oocrtes were collected from the oviduct of mice treated with pregnant mare's serum gonadotropin (PMSG) and human choronic gonadotropin (hCG). Whole cell voltage clamp technique and confocal microscopy were used to examine that $E_2$increase intracellular $Ca^{2+}$ concentration ([C $a^{2+}$]$_{i}$ ) via voltage dependent $Ca^{2+}$ channel (VDC) and estrogen receptor (FSR), and $E_2$concentration by the use of radioimmunoassay (RIA) were examined in mouse. The results obtained were as follows: The peak of $Ca^{2+}$ current induced by $E_2$increased 122% to 1.50$\pm$0.03 nA from 1.23$\pm$0.21 nA (n=15) in the presence of 5 mM extracellular $Ca^{2+}$ concentration ([C $a^{2+}$]$_{o}$ ). The increased $Ca^{2+}$ current was temporally associated with $Ca^{2+}$ transients. The intracellular $Ca^{2+}$ level increased 207%~30 s following the addition of 1${\mu}{\textrm}{m}$ $E_2$(relative fluorescence intensity: 836.4$\pm$131.2 for control, n=10, 1736.4$\pm$192.0 in the presence of $E_2$, n=10). $E_2$increased amplitude of $Ca^{2+}$ current and [C $a^{2+}$]$_{i}$ . $E_2$-induced $Ca^{2+}$ current and $E_2$concentration in blood were showed difference on the stage of embryo. These results suggest that $E_2$modulate $Ca^{2+}$ channel to increase $Ca^{2+}$ influx.$Ca^{2+}$ influx.

• Journal of Nutrition and Health
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• v.31 no.1
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• pp.21-27
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• 1998

The objective of this study was to observe the effect of dietary calcium(Ca) level on colonic mucosal levels of cell proliferation, 1, 2-diacylglycerol(DAG), TXB2, PGE2 and phospholipid fatty acid composition which have been known as biomarkers for colon cancer. One hundred male Sprague Dawley rats, at 7 weeks of age, were divided into two fat type groups. Each group of which was further divided into two Ca level groups. Each rt was intramuscularly injected with 1, 2,-dimenthylhydrazine(DMH) for 6 weeks (total dose of 180mg/kg body weight) and simultaneously fed one of four experimental diets containing 15% dietary fat(corn oil or perilla oil )and 0.3% or 1.0% Ca by weight for 20 weeks. Compared to corn oil, perilla oil significantly reduced cell proliferation by decreasing labeling index, proliferating zone, crypt length in colonic mucosa and colonic mucosa and colonic mucosal levels of DAG, TXB2 . PGE2 and phospolipid (PL) arachidonic acid distribution. The effect of Ca on biomarketrs was different depending on the type of dietary fat comsumed . Ca effect of Ca on biomarkers was different depending on the type of dietary fat comsumed. Ca effect was not significantly shown in the PO group, but it was significant in the CO group in which high Ca(1.0%) decreased the levels of levels of PL-C20 : 4(%), DAG and PGE2 . However , high Ca supplementation had shown only the trends of improving cell proliferation. Overall , high dietary Ca significantly reduced cell proliferation by inhibiting the synthesis of eicosanoid and DAG with reduced distribution of PL-C20 : 4 , which may have resulted in lower activation of PKC through reduced signal transduction. Since a high level of dietary Ca was more effective in reducing the risk factor against colon cancer in corn oil fed rats, it could be suggested that a higher amount of dietary Ca be consumed , especially when more vegetable oil rich in linoleic acid is included in the diet.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.3
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• pp.388-394
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• 2001

This study was conducted ton investigate the mineral contents of commercial baby foods. Samples were classified into 4 groups; powdered formula, baby juice product (domestic), juice and paste products (imported) and soymilk-based formula. We analyzed Ca, P, Mg, Na, K, Fe, Cu, Zn contents by atomic absorption spectrophotometer after dry-ashing. The difference of analyzed value versus labeled value and Ca/P ratio of analyzed value were calculated. The difference (%) of analyzed value on the labeled value was Ca: 98.6, P: 121.8, Mg: 146.1, Na: 87.4, K: 104.3, Fe: 104.8, Cu: 120.2, Zn: 109.8 in powdered formula, Mg showed the highest difference among the elements. The Ca/P ratio of powdered formula was 1.41 (1.70-1.99). Baby juice products (domestic) were fortified Ca, Fe and the difference (%) of analyzed value on labeled value of Ca and Fe contents was 131.8, 110.2, respectively. The Ca/P ratio of these was 2.36 (1.64-3.71). Differently the domestic products, imported juice and paste products were not fortified Ca, Fe and its Ca/P ratio was 0.38(0.14-0.59). The difference (%) of analyzed value on the labeled value was Ca: 110.2, Mg: 179.5, Na: 83.7, K: 87.8, Cu: 107.8, Fe: 219.8, Zn: 100.5, P: 126.6 in soymilk-based formula, Fe showed the highest difference among the elements. The Ca/P ratio of soymilk-based formula was 1.17 (1.04-0.39).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.3
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• pp.299-303
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• 1986

To provide useful information on the improving cultural practices of mungbean, investigations were made on Ca/Mg and (equation omitted) ratio in soil and plant grown under three fertilizer levels of N, P, K with different upland soils, using variety, Kyonggijaerae 5. Highly significant possitive correlations were observed between the soil extracted molar Ca/Mg ratio, (equation omitted) ratio at flowering time and yield, number of pods per plant, respectively. Soil-extracted Ca/Mg ratio at flowering time ranged from 1.9 to 6.4 and (equation omitted) ratio ranged from 0.17 to 0.33. Yield decreased rapidly as extracted soil Ca/Mg ratio became smaller than the ratio of 3.9, and yield was the highest the (equation omitted) ratio adjusted to 0.23 at flowering time. At harvesting time, Ca/Mg ratio in plant ranged from 1.4 to 4.3 and the yield decreased rapidly as Ca/Mg ratio in plant became smaller than 2.6. Yields, however, were not related to the soil-extracted Ca/Mg ratio interval from 3.9 to at least 6.4 in flowering time and Ca/Mg ratio in plant ranged from 2.6 to 4.3 at harvesting time.

• Journal of Animal Environmental Science
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• v.3 no.2
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• pp.97-104
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• 1997

This research was carried out to determine the effect of dietary calcium(Ca) levels(low : 0.29, medium : 0.65 and high : 1.07%) on the digestibility, excretion and retention of nitrogen(N) phosphorus (P) in pigs fed diets supplemented with phytase(750U/kg). Twelve growing-finishing pigs(average body weight: 35kg) were divided into 3 groups and these pigs were reared in metabolism cage. After 10 days adaptation period, N and P balance experiments were carried out for 4 days. The results were summarized as follows ; 1. The High-Ca group was lower than the others in digestibility of P(Low-Ca and Medium-Ca group). 2. The amount of daily excretion of urinary N were 19.6g in Low-Ca group and 16.7g in high-Ca group. The High-Ca group was the lowest(22.71%/d) in the total N excretion. 3. The High-Ca group was the highest and the Low-Ca group the lowest in fecal P excretion. The urinary P excretions per day were 1.90g in Low-Ca group and 0.04g in High-Ca group. The medium-Ca group showed the lowest total P excretion(4.57g/d). 4. The N retention of the High-Ca group(20.50g) was greater than that of the Low-Ca group and Medium-Ca(5.02)g was the highest and the Low-Ca groups(3.92g) was the lowest in the P retention. These results indicate that dietary Ca level was an important factor influencing N and P utilization in pigs.

• Journal of Nutrition and Health
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• v.40 no.5
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• pp.419-427
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• 2007

This study explored the effects of dietary calcium level and Hijikia fusiforme supplementation on bone indices and serum lipid levels using 36 female Sprague-Dawley rats as a model. Rats received low Ca diet for 3 weeks after ovariectomy. The rats were then divided into six dietary groups and fed low (0.1% Ca), normal (0.5% Ca) and high (1.5% Ca) Ca diets (CaL, CaN, CaH) and low, normal, high Ca diets with Hijikia fusiforme supplementation (CaLH, CaNH, CaHH) for 3 weeks. After each experimental periods, 24 hour urine and/or blood samples, left and right femurs were collected for analysis. Serum Ca concentration showed no significant difference by dietary Ca levels and Hijikia fusiforme supplementation. Alkaline phosphatase activity was significantly higher in normal and high Ca group compared to low Ca group. Serum total cholesterol, triglyceride and total lipid were not significantly different among groups. HDL-cholesterol showed no significant difference by Hijikia fusiforme supplementation. However, the normal and high Ca groups showed significantly higher HDL-cholesterol compared to the low Ca group. Urinary hydroxyproline and hydroxyproline/creatinine ratio were not significantly different among groups. The wet weight of the femur was significantly higher in low Ca group compared to normal or high Ca group. The dry weight, wet weight/body weight, length and breaking force of the femur were not significantly different among groups. Ash contents/wet weight of the femur was significantly increased as dietary Ca levels up and significantly higher in Hijikia fusiforme supplementation groups. The Ca content of the femur were significantly higher in the normal and high Ca groups than the low Ca group. However, there was no significant difference in Ca content by Hijikia fusiforme supplementation.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.2
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• pp.133-145
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• 1998

$Ca^{2+}-signals$ in endothelial cells are determined by release from intracellular stores and entry through the plasma membrane. In this review, the nature of $Ca^{2+}$ entry and mechanisms of its control are reviewed. The following ion channels play a pivotal role in regulation of the driving force for $Ca^{2+}$ entry: an inwardly rectifying $K^+$ channel, identified as Kir2.1, a big-conductance, $Ca^{2+}-activated$ $K^+$ channel (hslo) and at least two $Cl^-$ channels (a volume regulated $Cl^-$ channel, VRAC, and a $Ca^{2+}$ activated $Cl^-$ channel, CaCC). At least two different types of $Ca^{2+}$-entry channels exist: 1. A typical CRAC-like, highly selective $Ca^{2+}$ channel is described. Current density for this $Ca^{2+}$ entry is approximately 0.1pA/pF at 0 mV and thus 10 times smaller than in Jurkat or mast cells. 2. Another entry pathway for $Ca^{2+}$ entry is a more non-selective channel, which might be regulated by intracellular $Ca^{2+}$. Although detected in endothelial cells, the functional role of trp1,3,4 as possible channel proteins is unclear. Expression of trp3 in macrovascular endothelial cells from bovine pulmonary artery induced non-selective cation channels which are probably not store operated or failed to induce any current. Several features as well as a characterisation of $Ca^{2+}$-oscillations in endothelial cells is also presented.

• Journal of Nutrition and Health
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• v.32 no.1
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• pp.30-39
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• 1999

This study was designed to investigate the effect of Ca supplementation of 1,000mg per day for 53 weeks on lipid, Na, and K metabolism and on blood pressure in postmenopausal women. The subjects were 12 healthy women aged from 60 to 70 years. They were divided into two groups : the placebo(control group) and the Ca supplemented(1,000 mg/day) group(Ca group). Metabolic studies were conducted twice in the 1st and the 53rd weeks. The results were as follows : Serum triglyceride, total cholesterol and LDL-choesterol levels tended to be decreased after the experiment. Serum VLDL-cholesterol lowering effect was observed with Ca supplementation(p<0.05), and also the significantly elevated HDL/(LDL+VLDL) ratio in Ca supplemented subjects whose average Na intake was as high as 4.9g per day. This phenomena was accompanied with increased Na retention and increased Na excretion in feces, but with decreased urinary Na in Ca supplemented group. However, considering much higher Na reteniton in the control group at the end of experiment(control va Ca ; 1272.3mg vs 732.9mg), Ca supplementation may have some beneficial effects on Na blance. Serum aldosterone level increased significantly in the Ca group after the exsperiment(p<0.05). With these normotensive subjects, there were no level increased significantly in the Ca group after the experiment(p<0.05). With these normotensive subjects, there were no pronounced effect of Ca supplementation on blood pressure, however, decrease in diastolic blood pressure were observed at the 14th week and end of the experiment(p<0.05). In summary, the Ca supplementation on postmenopausal Koran women appears to exert a desirables effect on blood lipid patterns related to the coronary heart diseases and to be beneficial in controlling diastolic blood pressure. Further studies with hypertensive or/and hyperlipidemic subjects are required to clarify the effect of Ca supplementation in Koreans.

• Journal of the Korean Ceramic Society
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• v.48 no.3
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• pp.246-250
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• 2011

Effects on sintering and electrical properties of $La_{0.7}Ca_{0.3}Cr_{0.9}Co_{0.1}O_{3-{\delta}}$ system, a interconnect material for cylindrical and flat tubular solid oxide fuel cells (SOFC), have been investigated by Ca-source when using $CaCO_3$ and $CaF_2$. When using $CaCO_3$ and $CaF_2$ was mixing as Ca-source, single phased perovskite solid solution was observed for each sample. The sintering temperature was decreased by $CaF_2$ contents was increased. When using 0.1 mole $CaF_2$ was densely sintered at $1400^{\circ}C$ and relative density was 93.8%. Also, electrical conductivity in oxidation and reducing atmosphere was 47, 4.3 S/cm, respectively, due to $F^-$ ion enhance the electrical conductivity in reducing atmosphere.