• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.3
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• pp.255-261
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• 2006

This study was Conducted to investigate the effect of ${\gamma}-PGA\;({\gamma}-poly\;glutamic\;acid)$ on Ca absorption and bone metabolism in rats. Weaned 4-week old male rats were fed Ca-deficient diets for 3 weeks after the adjustment period. Rats were divided into 6 groups and were fed experimental diets for four weeks. Experimental groups were basal (Ca deficient), control (Ca diet: Ca 0.45%), CP1(Ca 0.45%+casein phosphopeptide 1%), PG1(Ca 0.45%+gamma poly glutamic acid 1%), CPG (Ca 0.45%+casein phosphopeptide 1%+gamma poly glutamic acid 1%) and PG3(Ca 0.45%+gamma poly glutamic acid 3%). Though daily Ca intake and food intake of experimental groups showed no significant difference that of control group. The values of fecal Ca excretion and urinary Ca excretion in groups fed ${\gamma}-PGA$ were significantly lower than that in tile control group. The values of Ca absorption in groups fed ${\gamma}-PGA$ were significantly higher than that in the control group. The levels of femur Ca in ${\gamma}-PGA$ supplemented group were significantly increased compared to the control group. Also, breaking force of femur in ${\gamma}-PGA$ supplemented group showed about 40% increase compared to the control group. These results show that ${\gamma}-PGA$ supplement could be helpful to increase Ca absorption as well as to intensify the femur strength and to increase the Ca content of femur in rats.

• Proceedings of the Korean Society of Crop Science Conference
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• 2004.04a
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• pp.68-69
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• 2004

• Proceedings of the Materials Research Society of Korea Conference
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• 1999.11a
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• pp.28-28
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• 1999

• Proceedings of the Materials Research Society of Korea Conference
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• 1999.05a
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• pp.133-133
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• 1999

• Journal of the Korean Ceramic Society
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• v.37 no.12
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• pp.1178-1186
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• 2000

타일의 내마모성과 내산성을 향상시키기 위해 결정화유리가 최근에 새로운 유약 재료로서 소개되고 있다. 신 유약의 연구에 사용된 조성은 $Ca_2$ZrSi$_4$O$_{12}$ 상에 근접하는 CaO-ZrO$_2$-SiO$_2$계의 유리조성의 분말로, 마이크로파 가열 (2.45 GHz)에 의해서 900-120$0^{\circ}C$의 0-20분간 소성되어 평가되었다. 그 결과, 100$0^{\circ}C$ 이상에서 소성한 시편은 내부 결정화를 나타내었으며, 결정상은 미세(5$mu extrm{m}$)한 크기를 갖는 $Ca_2$ZrSi$_4$O$_{12}$가 주 결정상이며, $Ca_2$ZrSi$_4$O$_{12}$, CaSiO$_3$, SiO$_2$의 세 상이 나타났다. 소결체의 미세구조는 사용한 유리분말의 입도의 영향을 받았다. 미세분말 (<38$\mu\textrm{m}$)을 이용한 소결체의 조직이 조세분말 (45-150$\mu\textrm{m}$)의 경우보다 수축율면에서 높았으며 낮은 기공도를 갖는 미세구조를 가졌다. 마이크로파에 의한 유리분말의 소성은 1000-120$0^{\circ}C$ 구간에서 10분 이내 결정화가 완료되는 급속 가열 공정이었으며 CaO-ZrO$_2$-SiO$_2$계 결정화 유리 제조에 균일한 체적가열을 할 수 있었다.

• Journal of Ginseng Research
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• v.18 no.2
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• pp.95-101
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• 1994

Saponin of Panax ginseng (C.A. Meyer) is composed of Protopanaxatriol (PT) and Protopanaxa- diol (PD). We investigated the effects of PT and PD on the contractility and $^{45}Ca$ uptake in the pig coronary artery. Isometric tension in the helical strips and $^{45}Ca$ uptake in the ring strips were measured in the presence or absence of PT and PD. PT and PD did not affect the high K+ (40 mM)-induced contraction but relaxed the ACh-induced contraction in a dose4ependent manner (1~10 mg/dl). The vasorelaxing effect of PT on the ACh-induced contraction was more potent than that of PD. Those relaxations were partially suppressed by the rubbing of endothelium removal. ACh-induced contraction in the $Ca^{2+}$-free Tyrode's solution was suppressed by the pretreatment of PT or PD. Following the depletion of ACh-sensitive intracellular $Ca^{2+}$ pool, ACh-induced contraction was suppressed by the pratreatment of PT or PD. With the pretreatment of PT or PD, $^{45}Ca$ uptake by high K+ (43 mM) was not changed but that by ACh was suppressed in the pig coronary artery. From the above results, we suggested that the vasorelaxing effect of PT and PD of Panax ginseng was due to inhibition of intracellular $Ca^{2+}$ release, inhibition of $Ca^{2+}$ uptake via receptor-operated $Ca^{2+}$ channels and in part a release of vasorelaxing factor from endothelium in pig coronary artery.

• The Korean Journal of Pharmacology
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• v.31 no.2
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• pp.207-217
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• 1995

To investigate the functional and immunological properties of the Ca-release channel in the sarcoplasmic reticulum(SR) of the eel skeletal muscle, $[^3H]ryanodine$ binding, SDS gel electrophoresis, $^{45}Ca\;release$ studies, and immunoblot assay were carried out in the SR of the eel skeletal muscle. Maximal binding sites(Bmax) and $K_D$ values of $[^3H]ryanodine$ for Ca-release channel of the SR of the eel skeletal muscle were $19.44{\pm}1.40\;pmole/mg$ protein and $15.55{\pm}1.69\;nM$, respectively. $[^3H]Ryanodine$ binding to RyR was increased by calcium and AMP. The SR of the eel skeletal muscle has two high molecular weight bands on the SDS PAGE. The mobility of upper band was more slower than the single band of the rabbit skeletal muscle, and that of the lower band was similar with the single band of canine cardiac muscle. Vesicular $^{45}Ca-release$ was activated by calcium. Ca-induced $^{45}Ca-release$ was significantly inhibited by $MgCl_2(2\;mM)$, ruthenium red$(10\;{/mu}M)$ or tetracaine(1 mM), but not by high concentration of calcium itself. AMP-induced $^{45}Ca-release$ was slightly occurred only in the absence of calcium, it was not inhibited by $MgCl_2$ or ruthenium red. Caffeine also increased $^{45}Ca-release$ from the SR vesicles, but it was not affected by $MgCl_2$ or ruthenium red. Polyclonal Ab against rat skeletal muscle RyR is reacted with that of rabbit, but not reacted with that of the eel skeletal muscle. These results suggested that ryanodine receptor of the SR of the eel skeletal muscle is showing some similar properties with that of mammalian skeletal muscle, but might be an another isotype channel having two bands which is less sensitive to AMP, not cross-reacted with antisera against rat RyR, and not inhibited by high concentration of calcium.

• Transactions on Electrical and Electronic Materials
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• v.15 no.1
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• pp.45-48
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• 2014

We have investigated the effects of an Ag capping layer on the emission characteristics of transparent organic light-emitting devices with Ca/Ag double-layer cathodes. The thickness of the Ag layer was varied from 10 to 30 nm, whereas the Ca was fixed to be a 10 nm in the Ca/Ag structure. The luminance and current efficiency on the cathode and anode sides are significantly dependent on the Ag thickness. For example, the current efficiency on the anode side increases from 8.4 to 11.7 cd/A, whereas, on the cathode side, it decreases from 3.2 to 0.2 cd/A as the Ag thickness increases from 10 to 30 nm. These changes in emission characteristics were investigated by measuring electroluminescence, transmission, and reflection spectra.

• Clinical and Experimental Reproductive Medicine
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• v.21 no.3
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• pp.285-296
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• 1994

Follicular oocytes were released from the graafian follicles of ovaries from 3-4 weeks old mice. The spontaenous maturation of these follicular oocyes was inhibited by the treatment of dbcAMP and progesterone and these oocytes were cultured for 2-8hr in the Modified Hank's balanced salt solution(MHBS). Ethylenediaminetetraaceticacid(EDTA) and calmoudulin antagonist, trifluoperazine (TFP) were treated to the culture medium in order to investigate whether these chemical agents inhibit calcium uptake into the oocyte and oocyte maturation. $^{45}Ca^{2+}$, 10-${\mu}$Ci/ml was added to the culture medium during the culture period. $^{45}Ca^{2+}$uptake into the oocytes was examined whether and when various kind of oocyte maturation inhibiting agents inhibit or stimulate the influx of calcium into oocytes. Dibutyryl cAMP and progesterone decrease $^{45}Ca^{2+}$uptake into the oocytes and synergistic inhibiting effect of dbcAMP and progesterone was prominent at much lower dosages. Calcium uptake into oocytes seems to be higher during first 2 hour culture period rather than next 4hr culture. After 8hr culture, calcium uptake level of the oocytes which GVBD already took place gradually approached to the level of those which were maintained at GV by the treatment of dbcAMP and progesterone. However, $^{45}Ca^{2+}$uptake into the GV maintained oocytes did not change at all even after 8hr culture period. In addition, calcium chelating agent, EDTA inhibited calcium uptake into oocytes as well as nuclear maturation of oocytes. Lower dosage used in the present study did not inhibit calcium uptake as well as oocyte maturation.

• Archives of Pharmacal Research
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• v.23 no.6
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• pp.633-636
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• 2000

Translationally controlled tumor protein (TCTP), also known as IgE-dependent histamine-releasing factor, is a growth-related tumor protein. Although the primary sequence of rat TCTP does not reveal any recognizable $Ca^{2+}$ -binding motif, previous studies have demonstrated that rat TCTP consisting of 172 amino acids is a $Ca^{2+}$ -binding protein. However. the region of TCTP required for $Ca^{2+}$ interaction has not been mapped to the molecule. Here, we reported that the $Ca^{2+}$ binding region of TCTP which was mapped by using a combination of deletion constructs of rat TCTP and $^{45}Ca^{2+}$-overlay assay. was confined to amino acid residues 81-112. This binding domain did not show any peculiar loop of calcium- binding motif such as CaLB domain and EF hand motif and it seems to be constituted of random coil regions neighboring the a helix. Thus, our data confirm that TCTP is a novel family of $Ca^{2+}$ -binding protein.