• 대한지역사회영양학회지
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• 제1권1호
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• pp.71-78
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• 1996

This study was conducted to compare the dietary factors which influence on the bone status of 28 women in urban and 30 women in rural area. Urinary excretion of hydroxyproline(Hpr) and Calcium(Ca) were measured as biological markers of bone resorption. Mean daily intake levels of total protein, animal protein, total calcium, calcium, calcium from milk and milk products, animal calcium, Ca / P ratio by 24 hr recall method were significantly higher in urban women. However, mean daily sodium(Na) intake levels were not significantly different between two groups. Ca Index score and Na Index score by food frequency methods were also significantly higher in urban than in rural subjects. While urinary Ca excretion elves of two groups were similar, Na excretion levels were significantly higher in rural women. Mean urniary levels of Ca / creatinine(cr) and Hpr / cr as bone status index were within normal range and not significantly different between two groups. However, prevalence of poor bone status as assessed by hydroxyproline was higher in rural women. Na Index, urinary Ca excretion and Ca / cr ratio were significantly correlated with bone status(Hpr / cr) in urban women, while only age was related to bone status in rural women. These demonstrated that high Na intake results in increased urinary excretion of Na and Ca and could cause bone resorption. Multiple regression analysis indicated that Na Index score and age have greater effect than other variables in urban women and only age has greater effect in rural women.

• Journal of Nutrition and Health
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• 제26권6호
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• pp.728-742
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• 1993

The effects of dietary calcium levels on the blood pressure and calcium metabolism were investigated. Nine normotensive female college students having hypertention family history were participated in 4-week dietary expeiments. They were provided with either high Ca diet (HCa, average 797mg/day) or low Ca diet(LCa, average 225mg/day) during two weeks, each, consecutively. Sodium amounts of the body diets were 3566~4022mg/day, which were ordinary sodium intake levels in Korea. After the HCa, systolic blood pressures(SBR) in both seated and isogrip-seated postitions were decreased by about 2.5mgHg, comparing with those after the LCa(p<.05). Diastoilc blood pressures(DBP) were not changed by dietary calcium levels. Serum total Ca, ionized Ca, Mg and P levels and Ca/Mg ratio were not different between the HCa and the LCa. Serum parathyroid hormone(PTH) levels were similar between two diets, but individually in seven of nine subjects, the slightly lower values of PTH were observed after the HCa than after the LCa. Urinary excretion of Ca(p<.01), Mg(p<.05) and P(p<.1) were increased after the HCa comparing with the LCa, but Ca/Mg ratio were not different between the two diets. SBP was in positive correlations with boty urinary excretion of Ca(supine, r=.7356, p<.05) and urinary Ca/Mg ratio(isogrip-seated, r=.7483, p<.05). SBP was also negatively correlated with serum P level(supine, r=-.6930, p<.05) and DBP was in negative correlation with urinary P excretion(seated, r=-.8586, p<.01). Serum total and ionized Ca, Mg, Ca/Mg ratio were not significantly correlated with blood pressures.

• 한국재료학회지
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• 제13권4호
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• pp.246-250
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• 2003

Calcium phosphate was prepared by chemical reaction formula using Oyster shells and $H_3$$PO_4$solutions. After added to 0.1 M∼0.9$ M H_3$$PO_4$ solution for oyster shell, prepared powders were investigated for heating properties and formation phase with heat treatment temperatures. As the results of XRD analysis of heated powders at $500^{\circ}C$∼$1200^{\circ}C$,$ CaCO_3$ phases were observed at the temperature of below 900 TEX>$^{\circ}C$ and in the condition of 0.1 M∼0.9 M $H_3$$PO_4$ solutions. However, $CaCO_3$, $CaPO_3$(OH) and $Ca_3$($PO_4$)$_2$ phases were appeared at the temperature range between $500∼900^{\circ}C$ and in the solution of 0.7 M to 0.9 M $H_3$$PO_4$. $Ca_{ 5}$($PO_4$)$_3$(OH) and CaO phases due to the decarbonation of oyster shells($CaCO_3$) were appeared at above $1000^{\circ}C$ and in the solution of below 0.5 M $H_3$X$PO_4$. However in the case of above 0.7 M $H_3$$H_4$ solutions, $Ca_{5}$ ($PO_4$)$_3$(OH) was decomposed into $Ca_3$($PO_4$)$_2$ at more higher 100$0^{\circ}C$. Thus $Ca_3$(X$Ca_4$)$_2$ phases were appeared at higher than 100$0^{\circ}C$.

• Journal of Nutrition and Health
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• 제26권3호
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• pp.277-285
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• 1993

To investigate the effects of dietary calcium levels on the Ca metabolism in a rat model of ovariectomized osteoporosis, two studies were conducted. In Expt. I, five week-old femalc rats ovariectomized and fed a low Ca diet(0.06% Ca) for four weeks were compared with rats fed a normal (0.53% Ca) or low Ca diet under the sham-operated condition. Ovariectomized rats showed a significant increase in body weight and food intake. In rats fed the low Ca diet, a remarkable decrease was shown regardless of ovariectomy in serum Ca concentration, breaking force of bones, Ca and phopsphrus contents of bones, and apparent absorption and retention of Ca. Furthermore hte decrease of Ca contents of serum and bones in rats ovariectomized and fed the low Ca diet was similar to that in rats model of postmenopausal osteoporosis. In Expt. II, rats ovariectomized and fed on the low Ca diet for four weeks were divided into three groups, those given low Ca diet, normal Ca diet and high Ca diet(1.06%) respectively. The results indicated that supplementations of Ca at the intake level of 0.53% and 1.06% for 4 weeks tend to improve the relative Ca deficiency shown in experimental rat model of ovariectomized osteoporosis.

• Toxicological Research
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• 제14권4호
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• pp.507-513
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• 1998

The purpose of this study was to clarify the effect of silica on cytosolic free calcium mobilization and cell injury in primary cultured rat hepatocytes. Cytosolic free calcium concentration ([Ca$^{2+}$]) was measured employing calcium sensitive fluorescent dye, Fura-2 / AM, and cell injury was evaluated by determination of cellular ATP contents. Silica increased [Ca$^{2+}$], in a concentration-dependent manner in hepatocytes (10$^{-5}$ ~10$^{-2}$ M). Silica caused a biphasic increase in [Ca$^{2+}$], which was composed of an initial rapid rise and following sustained phase. $Ca^{2+}$ removal from the medium resulted in abolishment of initial and sustained phase of silica (10$^{-2}$ M)-induced [Ca$^{2+}$], in hepatocytes. The pretreatment with nifedipine (1 $\mu$M) attenuated silica-induced [Ca$^{2+}$], increases. Silica decreased cellular ATP contents in a dose-dependent manner. This silica-induced cell injury was attenuated by the pretreatment with EGTA (100 $\mu$M) and nifedipine (1 $\mu$M). This study suggests that the elevation of [Ca$^{2+}$], caused by silica may be due mainly to influx through a plasma membrane $Ca^{2+}$ channel and hepatotoxicity by silica relate with alteration of calcium homeostasis.ium homeostasis.

• The Korean Journal of Physiology and Pharmacology
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• 제14권1호
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• pp.51-57
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• 2010

It was hypothesized that NaF induces calcium sensitization in $Ca^{2+}$-controlled solution in permeabilized rat mesenteric arteries. Rat mesenteric arteries were permeabilized with $\beta$-escin and subjected to tension measurement. NaF potentiated the concentration-response curves to $Ca^{2+}$ (decreased $EC_{50}$ and increased $E_{max}$). Cumulative addition of NaF (4.0, 8.0 and 16 mM) also increased vascular tension in $Ca^{2+}$-controlled solution at pCa 7.0 or pCa 6.5, but not at pCa 8.0. NaF-induced vasocontraction and $GTP{\gamma}S$-induced vasocontraction were not additive. NaF-induced vasocontraction at pCa 7.0 was inhibited by pretreatment with Rho kinase inhibitors H1152 or Y27632 but not with a MLCK inhibitor ML-7 or a PKC inhibitor Ro31-8220. NaF induces calcium sensitization in a $Ca^{2+}$ dependent manner in $\beta$-escin-permeabilized rat mesenteric arteries. These results suggest that NaF is an activator of the Rho kinase signaling pathway during vascular contraction.

• 한국치위생학회지
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• 제17권2호
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• pp.283-294
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• 2017

Objectives: The purpose of the study was to investigate the effect of calcium concentration in saliva on dental caries activity after consuming calcium. Methods: A total of 59 adult women aged 20 to 40 years were surveyed for calcium intake. The daily average calcium intake was analyzed through dietary records of the subjects. The subjects were divided into two groups based on daily average calcium intake. Salivary pH and concentrations of minerals in the saliva were obtained from A group and B group. Calcium ($Ca^{2+}$) and magnesium ($Mg^{2+}$) concentrations in saliva were measured by HPLC-Ion chromatography using 15 mM sulfuric acid. The dental caries activity test was quantified by salivary buffer capacity test and plaque pH test. Results: The mean $Ca^{2+}$ concentrations of A group was $12.75{\mu}g/m$, the mean $Ca^{2+}$ concentrations in the B group was $16.30{\mu}g/mL$ (p<0.05) and respectively, $Mg^{2+}$ concentrations were found to be $0.48{\mu}g/mL$ and $0.51{\mu}g/mL$. Calcium intake and calcium concentration in saliva showed a significant correlation (r=0.380). Conclusions: The mean $Ca^{2+}$ concentrations in saliva was higher in the high calcium intake group. Therefore, calcium intake in saliva was correlated with dental caries.

• 한국축산시설환경학회지
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• 제3권2호
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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.

• International Journal of Oral Biology
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• 제35권3호
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• pp.129-135
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• 2010

Recent studies have implicated reactive oxygen species (ROS) as determinants of the pathological pain caused by the activation of peripheral neurons. It has not been elucidated, however, how ROS activate the primary sensory neurons in the pain pathway. In this study, calcium imaging was performed to investigate the effects of NaOCl, a ROS donor, on the intracellular calcium concentration ($[Ca^{2+}]i$) in acutely dissociated dorsal root ganglion (DRG) neurons. DRG was sequentially treated with 0.2 mg/ml of both protease and thermolysin, and single neurons were then obtained by mechanical dissociation. The administration of NaOCl then caused a reversible increase in the $[Ca^{2+}]i$, which was inhibited by pretreatment with phenyl-N-tertbuthylnitrone (PBN) and isoascorbate, both ROS scavengers. The NaOCl-induced $[Ca^{2+}]i$ increase was suppressed both in a calcium free solution and after depletion of the intracellular $Ca^{2+}$ pool by thapsigargin. Additionally, this increase was predominantly blocked by pretreatment with the transient receptor potential (TRP) antagonists, ruthenium red ($50\;{\mu}M$) and capsazepine ($10\;{\mu}M$). Collectively, these results suggest that an increase in the intracellular calcium concentration is produced from both extracellular fluid and the intracellular calcium store, and that TRP might be involved in the sensation of pain induced by ROS.

• Animal cells and systems
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• 제7권1호
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• pp.75-79
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• 2003

Highly purified high performance thin layer chromatography (HPTLC) fractions containing a putative calcium influx factor (CIF) were prepared from the Jurkat cells and Xenopus oocytes in which $Ca^{2+}$ stores were depleted by thapsigargin treatment and from the yeast in which intracellular $Ca^{2+}$ stores were also depleted by genetic means. Microinjection of the fractions has been shown to elicit $Ca^{2+}$ dependent currents in Xenopus oocytes. The nature of the membrane currents evoked by the putative CIF appeared to be carried by chloride ions since the current was blocked by the selective chloride channel blocker 1 mM niflumic acid and its reversal potential was about -24 mV. Injection of the calcium chelator 1,2-bis(2-aminophenoxy)ethane-N, N, N',N'-tetraacetic acid (BAPTA) eradicated the current activities, suggesting the current responses are entirely $Ca^2$-dependent. Moreover, the currents were sensitive to the removal of extracellular calcium, indicating the dependence on calcium entry through the plasma membrane calcium entry channels. CIF activities were insensitive to protease, heat, and acid treatments and to Dische-reaction whereas the activities were sensitive to nucleotide pyrophosphatase and hydrazynolysis. The fraction might have a sugar because it was sensitive to Molisch test and Seliwaniff's resorcinol reaction. From the above results, CIF as a small and stable molecule seems to have pyrimidine, pyrophosphate, and a sugar moiety.oiety.