• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.4
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• pp.931-936
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• 1996

Many kinds of soluble calcium salts such as calcium lactate are known to reduce the enamel demineralization. In this study, calcium lactate was tested for its effect on the demineralization process of hydroxyapatite. Synthetic hydroxyapatites were used as a standardized material instead of human enamel which is rarely heterogenous. And, for the purpose of hydroxyapatite demineralization, lactic acid was used. By comparing the weight of hydroxyapatite pre-demineralization and post-demineralization, it was possible to examine the effect of calcium lactate on demineralization. The weight of demineralized hydroxyapatite was reduced by about 46% and 59% with 20mM and 40mM calcium lactate, respectively. In conclusion, low concentrations of calcium lactate showed an inhibitory effect on the demineralization of synthetic hydroxyapatite.

• Journal of the East Asian Society of Dietary Life
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• v.5 no.3
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• pp.287-298
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• 1995

This study was undertaken to examine the effect of salting in 10% salt solution added 2% calcium chloride on the kimchi fermentation. The addition of calcium chloride extended edible periods of the Kimchi to 4~5 days and increased relatively the hardness of Chinese Cabbage. In the addition of calcium chloride, the activities of amylase and $\beta$ -galactosidase were not high during all periods fermentation. Polygalacturonase and protease activities were low 2~21%, 2~26% all periods fermentation, respectively. There were significant correlations between the delay of ripeness and decreasing enzyme activation. The amount of free amino acid by the treatment with calcium chloride was decreased of 10~16% at the late of fermentation than that of control. the treatment with calcium chloride of the Kimchi was increased hardness, but decreased cohesiveness and gumminess was during all periods fermentation. the adhesiveness was increased at the early of fermentation but decreased at the late of fermentation.

• Preventive Nutrition and Food Science
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• v.15 no.4
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• pp.282-286
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• 2010

To isolate a calcium-binding peptide from chlorella protein hydrolysates, chlorella protein was extracted and hydrolyzed using Flavourzyme, a commercial protease. The degree of hydrolysis and calcium-binding capacity were determined using trinitrobenzenesulfonic acid and orthophenanthroline methods, respectively. The enzymatic hydrolysis of chlorella protein for 6 hr was sufficient for the preparation of chlorella protein hydrolysates. The hydrolysates of chlorella protein were then ultra-filtered under 5 kDa as molecular weight. The membrane-filtered solution was fractionated using ion exchange, reverse phase, normal phase chromatography, and fast protein liquid chromatography to identify a calcium-binding peptide. The purified calcium-binding peptide had a calcium binding activity of 0.166 mM and was determined to be 700.48 Da as molecular weight, and partially identified as a peptide containing Asn-Ser-Gly-Cys based on liquid chromatography/electrospray ionization tandem mass spectrum.

• Journal of Practical Agriculture & Fisheries Research
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• v.6 no.1
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• pp.73-80
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• 2004

This study was conducted to determine the effect of several kinds of calcium foliar application and drip irrigation on the bitter pit incidence of apple. CaCl₂, inorganic calcium compound, was the most effective in increasing the calcium concentration in the fruit flesh, and reducing bitter pit incidence. Calcium spray in the later part of the growing season was more effective than in the earlier part. Drip irrigation applied during the dry spells increased calcium concentration in the fruit flesh, and reduced bitter pit incidence.

• Archives of Pharmacal Research
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• v.13 no.4
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• pp.379-381
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• 1990

The effect of calcium gluconate on estrogen (estradiol) serum level as well as follicle stimulating hormone level was studied. Our results revealed that oral administration of calcium gluconate (100 mg/kg body wight) to adult non-pregnant female rabbits caused a significant increase of serum levels of estradiol and follicle stimulating hormone. On the other hand, oral contraceptive (Norminest tablets) decreased significantly follicle stimulating hormone serum level, while combined administration of calcium gluconate and oral contraceptive caused significant increase of serum level of follicle stimulating hormone compared with control values. Also, concurrent administration of calcium gluconate and Norminest tablet increased significantly the rate of conception compared with group recieved Norminest tablets only. These results indicated that combined administration of calcium and oral contraceptives must be cautiously.

• Journal of Yeungnam Medical Science
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• v.9 no.2
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• pp.359-381
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• 1992

This study was designed to investigate the effect of diazepam on the spontaneous contraction and oxytocin induced contraction of the isolated rat uterus. Female rat(Sprague-Dawley) pretreated with oophorectomy and 4 days administration of estrogen, weighing about 200 g, was sacrificed by cervical dislocation, and the uteruses were isolated. A longitudinal muscle strip was placed in temperature controlled($37^{\circ}C$) muscle chamber containing Locke's solution and myographied isometrically. Diazepam inhibited the spontaneous contraction and oxytocin induced contraction of the isolated rat uterus in a concentration-dependent manner. GABA, muscimol, a GABA A receptor agonist, bicuculline, a competitive GAGA A receptor antagonist, picrotoxin, a non competitive GABA A receptor antagonist, baclofen, a GABA B receptor agonist, and delta-aminovaleric acid, a GABA B receptor antagonist, did not affect on the spontaneous and oxytocin induced contraction of the isolated rat uterus. The inhibitory actions of diazepam on the spontaneous and oxytocin induced contraction were not affected by all the GABA receptor agonists and antagonists, but exceptionally potentiated by bicuculline. This potentiation-effect by bicuculline was not antagonized by muscimol. In normal calcium PSS, addition of calcium restored the spontaneous contraction preinhibited by diazepam and recovered the contractile of oxytocin preinhibited by diazepam. A23187, a calcium inophore, enhanced the restoration of both the spontaneous and oxytocin induced contraction by addition of calcium. In calcium-free PSS, diazepam suppressed the restoration of spontaneous motility by addition of calcium but allowed the recovery of spontaneous motility to a considerable extent. Diazepam could not inhibit some development of contractility by oxytocin in calcium-free PSS, but inhibited the increase in contractility by subsequent addition of calcium. These results suggest that the inhibitory action of diazepam on the rat uterine motility does not depend on or related to GABA receptors and that diazepam inhibits the extracellular calcium influx to suppress the spontaneous and oxytocin induced contractilities.

• Journal of the Korean Chemical Society
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• v.57 no.1
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• pp.99-103
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• 2013

The present communication deals with the Pharmacophore modeling, 3D QSAR and docking analysis on series of Pyrimidine derivatives as potential calcium channel blockers. The computational studies showed hydrogen bond donor, hydrogen bond acceptor, and hydrophobic group are important features for calcium channel blocking activity. These studies showed that Pyrimidine scaffold can be utilized for designing of novel calcium channels blockers for CVS disorders.

• Journal of Periodontal and Implant Science
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• v.26 no.3
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• pp.605-624
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• 1996

Various bonegraft materials and the technique of guided tissue regeneration have been used to regenerate lost periodontal tissue. Calcium sulfate has been known as a bone graft material because of good biocompatibility, rapid resorption and effective osteoinduction. It has been known that calcium sulfate works as a binder to stabilize the defect when it is used with synthetic graft materials. The effects on the regeneration of pericxiontal tissue were studied in dogs after grafting 3-wall intrabony defects with calcium carbonate and calcium sulfate and covering with calcium sulfate barrier. The 3-wall intrabony defectstdmm width, 4mm depth, 4mm length) were created in anterior area and treated with flap operation alone(contol group), with porous resorbable calcium carbonate graft alonetexperirnental group 1), with calcium sulfate graft alonetexperimental group 2) and with composite graft of 80% calcium carbonate and 20% calcium sulfate with calcium sulfate barriertexperimental group 3). Healing responses were histologically observed after 8 weeks and the results were as follows: 1. The alveolar bone formation was $0.59{\pm}0.19mm$ in the control group, $1.80{\pm}0.25mm$ in experimental group 1, $1.61{\pm}0.21mm$ in experimental group 2 and $1.94{\pm}0.11mm$ in experimental group 3 with statistically significant differences between control group and all experimental groups(P<0.05). There were statistically significant differences between experimental group 1 and group 2 (P<0.05). 2. The new cementum formation was $0.48{\pm}0.19mm$ in the control group. $1.72{\pm}0.26mm$ in experimental group 1, $1.43{\pm}0.17mm$ in experimental group 2, $1.89{\pm}0.15mm$ in experimental group 3 with statiscally significant differences between control group and all experimental groups (p<0.05). There were statistically significant differences between experimental group 1 and group 2, and between experimental group 2 and group 3(P<0.05). 3. The length of junctional epithelium was $1.61{\pm}0.20mm$ in the contol group, $0.95{\pm}0.06mm$ in experimental group 1, $1.34{\pm}0.16mm$ in experimental group 2, $1.08{\pm}0.11mm$ in experimental group 3 with statiscally significant differences between control group and experimental group 1. and btween control group and experimental group 3(p<0.05). There were statistically significant differences between experimental group 1 ,and group 2, and between experimental group 2 and group 3(P<0.05). 4. The connective tissue adhesion was $1.67{\pm}O.20mm$ in the control group, $1.33{\pm}0.24mm$ in experimental group 1. $1.23{\pm}0.16mm$ in experimental group 2, $1.08{\pm}0.14mm$ in experimental group 3 with statistically significant differences between control group and all experimental groups(p<0.05). There were nostatistically significant differences between all experimental groups. As a result, epithelial migration was not prevented when calcium sulfate was used alone, but new bone and cementum formation were enhanced. Epithelial migration was prevented and new bone and cementum formation were also enhanced when calcium carbonate was used alone and when both calcium carbonate and calcium sulfate were used.

• The Korean Journal of Physiology
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• v.27 no.2
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• pp.175-183
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• 1993

There are many report suggesting that influx and intracellular calcium concentration $([Ca^{2+}]_i)$ are related to cell signalling in various cells. However, it has not been reported that calcium channel activation is affected by the substances involved in signal transduction pathways in the mouse eggs. In this study, the effects of isoprenaline (ISP) and cyclic AMP on calcium influx through calcium channels were investigated to show their relationship with the signal transduction process in unfertilized mouse eggs. Using whole cell voltage clamp techniques, calcium currents, elicited by the depolarizing pulses of 300 ms duration (from -50 mV to 50 mV in 10 mV increments) from a holding potential of -80 mV, were recorded. The current-voltage (I-V) relation of calcium currents was shown to be bell-shaped; the current began to activate at -50 mV and reached its maximum $(-1.33{\pm}0.16\;nA:\;mean{\pm}S.E.,\;n=7)$ at -10 mV, then decayed at around 50 mV. Calcium currents were fully activated within $7\;ms{\sim}20\;ms$ and completely inactivated 200 ms after onset of the step pulse. ISP within the concentration ranges of $10^{-8}\;M{\sim}10^{-4}\;M$ dose-dependently increased the amplitude calcium current. The permeable cyclic AMP analogue,8-bromocyclic AMP, also increased its maximal amplitude by 46ft at $10^{-5}\;M$, while protein kinase inhibitor (PKI), which is known to inhibit 0.02 phosphorylating units of cyclic AMP-dependent protein kinase (PKA) per microgram decreased calcium currents. Currents recorded in the presence of PKI were resistant to increase by the application of $10^{-5}\;M$. Also, PKI inhibited the calcium current increase elicited by ISP treatment. These results suggest that $\beta-adrenergic$ regulation of the calcium channel is mediated by the cAMP-dependent protein kinase. This signal transduction pathway might play a role in regulating $[Ca^{2+}]_i$, level due to the increase of calcium influx in mouse eggs.

• Journal of Environmental Health Sciences
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• v.14 no.2
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• pp.73-87
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• 1988

This study was performed to investigate the effect of lactose in 4 different concentrations against the protective effect of calcium on the acute lead poisoning in rats after 4 weeks treatment. In this animal experiment, 70 albino male weanling rats (50-70g of body weight) of Sprague-Dawley strain were used. Lead was dissolved in the distilled water and intubated at the dose of 400mg lead (as acetate)/ kg of body weight/day. Calcium and lactose were administered in drinking water ad libiturn dissolved with the solution of 0.7% calcium gluconate mixed with 40, 80, 160 and 320mM lacotse respectively. The results obtained were summarized as follows: 1. The rate of body weight gain in all treated groups turned out to be lower than that in the control group during 4 weeks treatment. The slow-down of body weight gain was the most significantly observed in the group treated with lead only ( p < 0.05). 2. The relative spleen weight in lead only treated group was significantly lower than that of lead + calcium, lead + calcium + 80mM lactose treated group ( p < 0.05). 3. The value of RBC, WBC, Hb and Hct showed a decreasing tendency in the group treated with lead only ( p < 0.05), however, a significant decrease was not observed in the group treated with lead + calcium. On the other hand, the protective effect of calcium was deteriorated in the group treated with lead + calcium + lactose. 4. The activity of $\delta$-aminolevulinic acid dehydratase ($\delta$-ALAD activity) showed the same tendency as No. 2. 5. The lead concentration in the blood (PbB) showed an increasing tendency and the interrelation among the different groups was also identical with No. 2. 6. With a statistical approach, it was found out that the activity of $\delta$-ALAD and the lead concentration in the blood show a relation of inverse proportion(r=-0.7301). The diagram was interpreted with the logarithmic equation InY = 5.5357-0.0251X (X:PbB, Y:$\delta$-ALAD activity). 7. In the histopathological findings of the kidney, the protective effect of calcium was observed. However, the protective effect of calcium was restricted in the group treated with lead + calcium + lactose. As a conclusion, the intensity of the acute ingested lead poisoning was obviously reduced by calcium, however, the protective effect of calcium was deteriorated in proportion with the concentration of the lactose to be administered. On the other hand, it was also noted that the deterioration was lightly restrained in the group treated with the physiological concentration of 80mM lactose than the results shown in the groups treated with lactose of other concentrations.