• The Korean Journal of Pharmacology
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• v.21 no.2
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• pp.79-89
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• 1985

Mechanism of calcium transport inhibition of cardiac sarcoplasmic reticulum (SR) by oxygen free radicals was examined. Effects of oxygen free radicals generated by xanthine/xanthine oxidase (X/XO) system on isolated porcine ventricle SR were studied with respect to its calcium binding, lipid peroxidation, SH-group content and alteration of membrane protein components. The results are as follows. 1) Calcium binding of isolated SR was markedly inhibited by X/XO. 2) During the incubation of sarcoplasmic reticulum with xanthine/xanthine oxidase, there were marked inclose in lipid peroxidation and reduction of SH-group content. 3) An antioxidant, p-phenylenediamine effectively prevented the lipid peroxidation but partially prevented the calcium binding inhibition of X/XO treated SR. 4) The reduction of SH-group content of SR treated with X/XO was partially prevented by p-phenylendiamine. 5) When modifying SH-group of SR by treatment with DTNB, the inhibition of calcium binding activity was partially prevented. 6) On gel-permeation chromatography of X/XO-treated sarcoplasmic reticulum, there was an increase of small molecular weight products, probably protein degradation products. 7) Semicarbazide, which prevents the cross-linking reaction of protein components, did not affect the calcium binding inhibition of X/XO-treated SR. From these results, it is suggested that the inhibition of calcium binding of SR by oxygen free radicals results from the consequence of multiple changes of SR components, which are lipid peroxidation, SH-group oxidation and degradation of protein components.

• BMB Reports
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• v.43 no.3
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• pp.151-157
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• 2010

$Ca^{2+}$ is a universal signalling molecule that affects a variety of cellular processes including cardiac development. The majority of intracellular $Ca^{2+}$ is stored in the endoplasmic and sarcoplasmic reticulum of muscle and non-muscle cells. Calreticulin is a well studied $Ca^{2+}$-buffering protein in the endoplasmic reticulum, and calreticulin deficiency is embryonic lethal due to impaired cardiac development. Despite calsequestrin being the most abundant $Ca^{2+}$-buffering protein in the sarcoplasmic reticulum, viability is maintained in embryos without calsequestrin and normal $Ca^{2+}$ release and contractile function is observed. The $Ca^{2+}$ homeostasis regulated by the endoplasmic and sarcoplasmic reticulum is critical for the development and proper function of the heart.

• Journal of Chest Surgery
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• v.19 no.2
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• pp.197-208
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• 1986

Propranolol is one of clinically useful antiarrhythmic agents and electrophysiologically classified as group II. And the negative inotropic effect which is not related to adrenolytic effect has been demonstrated with high concentration of propranolol. On the other hand, it has been well known that the calcium plays a central role in excitation-contraction coupling process of myocardium and also in electrophysiological changes of cell membrane. Author studies the effect of propranolol on calcium uptake and release in sarcoplasmic reticulum and mitochondria prepared from porcine myocardium to investigate the mechanism of action of propranolol on myocardium. The results are summarized as follow: 1] The maximum Ca++-uptake of sarcoplasmic reticulum is inhibited by propranolol in a dose dependent manner. 2] The release of calcium from sarcoplasmic reticulum is not affected by propranolol but with higher than 1x10-3 M of propranolol, rate of calcium release from sarcoplasmic reticulum is decreased. 3] Propranolol inhibits the maximum uptake and uptake rate of calcium in mitochondria non-competitively. [Ki = 6.21 x 10-4 M] 4] The rate of Na+ induced calcium release from mitochondrion shows a function of [Na+]2 and is inhibited by propranolol with the concentration significantly lower than that affect the calcium uptake in sarcoplasmic reticulum and in mitochondria [Ki = 2.91 x 10-5 M]. These results suggest that propranolol affects the intracellular calcium homeostasis which may considered to be one of the mechanism of action of propranolol on myocardium.

• Journal of Ginseng Research
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• v.15 no.2
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• pp.131-138
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• 1991

This study was carried out to investigate the development of endoplasmic reticulum and the formation of Protein body in the endosperm cell during seed formation of Panax ginseng C. A. Meyer with electron microscope. In the endosperm cell of early developmental process after pollination, vesicles that contain storage materials produced in rough endoplasmic reticulum incorporated into central vacuole. The central vacuole is gradually subdivided into several small-sized vacuoles and increased in number. Amorphous proteinaceous materials of high electron density are produced in rough endoplasmic reticulum. Rough endoplasmic reticulum increase in number and surround the protein body and vesicles circularly. Spherical proteinaceous granules with limited membrane appeared from the amorphous granules at the peripheral region of the rough endoplasmic reticulum. Gradually, storage materials are accumulated within the vacuole surrounded by spherosomes. Protein bodies are formed by interfusing between vacuoles and vesicles derived from rough endoplasmic reticulum which contained the amorphous protein of high electron density.

• Journal of Life Science
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• v.9 no.1
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• pp.90-92
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• 1999

Deficient thyroglobulin is one of the important causes of congenital hypothyroid goiter with a prevalence of -1/40,000 humans. We now demonstrate that in cog/cog mice showing hypothyroidism, four endoplasmic reticulum-molecular chaperones stably bind to thyroglobulin, providing insight into physiologic regulation of endoplasmic reticulum storage diseases.

• The Korean Journal of Zoology
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• v.33 no.2
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• pp.191-199
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• 1990

Sarcoplasmic reticulum subfractions were isolated from rabbit sarcoplasmic reticulum vesicles using ultracentrifugation in a continuous sucrose gradient (12.5% 50%) after French pressure treatment. And proteins in sarcoplasmic reticulum were detected by SDS-polyacrylamide gel electrophoresis and glycoproteins were identified through the reaction with 1251-concanavalin A.The electrophoresis showed that sarcoplasmic reticulum contained predominantly $Ca^2$+-AThase and calsequestrin along with high affinity calcium binding protein, intrinsic glycoprotein 160 Kd, 94 Kd, 80 Kd, 38 Kd, 34 Kd and 24 Kd proteins. Among these, the protein of about 80 Kd which has been known as one of heat shock proteins was especially enriched in the terminal cistemae of sarcoplasmic reticulum. Meanwhile, autoradiogram of 125 I-concanavalin A bound to the stained gels showed the distribution of glycoproteins which included 160 Kd glycoprotein, 94 Kd glycoprotein, calsequestrin and intrinsic glycoprotein Among these, the protein of about 160 Kd was especially enriched in longitudial sarcoplasmic reticulum and T-tubule, and the protein of about 94 Kd which has been known as one of glucose-regulated proteins was also enriched in T-tubule and sharply reduced in terminal cistemae.

• Journal of Animal Science and Technology
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• v.45 no.6
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• pp.967-974
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• 2003

This experiment was carried out to investigate the relationship of morphological characteristics between reticulum and abomasum of Korean native young goats age from 2 days to 150 days. Number of traits investigated in the reticulum in this experiment were 12[body weight, chest girth, body length, right and left reticulum length(R.L.), upper and lower reticulum length(U.L.), reticulum weight(R.W.), reticulum area(R.A.), upper and lower length of one polygon located at central part of reticulum(U.P.C.R.), right and left length of one polygon located at central part of reticulum(R.P.C.R.), thickness of polygon wall located at central part of reticulum(T.P.C.R.), thickness of polygon wall located at middle part of reticulum(T.P.M.R.), and thickness of polygon wall locared at edge part of reticulum(T.P.E.R.)] and items for abomasum were 12[length of between ostium omaso-abomasicum part and pylosica part in the abomasum(L.B.O.P.), broadest outer part of the abomasum(B.O.A.), weight of abomasum(W.O.A.), area of abomasum(A.O.A.), number of plicae abomasi in the abomasum(N.P.A.A.), thickness of abomasum well at cranial part(ostium omasoabomasicum) in the abomasum(T.A.C.A.), thickness of abomasum well at central part in the abomasum(T.A.P.A.), thickness of abomasum wall at light upper area of pylosica part in the abomasum(T.A.L.A.), length measured from the longest plica abomasi in the abomasum(L.L.P.A.), broadest measured from the longest plica abomasi in the abomasum(B.L.P.A.), area measured from the longest plica abomasi in the abomasum(A.L.P.A.), weight of longest plica abomasi in the abomasum(W.L.P.A.)]. The results were summarized as follows: 1. Number of coefficient of correlation obtained among 12 traits of the abomasum and 12 of the reticulum were 144, and coefficient of correlation of 114 were significant(P〈0.05). 2. Trait of abomasum weight have high correlation with 12 traits of reticulum. 3. Correlation coefficients and regression equation between body weight. VS. abomasum weight(r$_1$), and upper and lower length of one polygon located at central part of reticulum(U.P.C.R.) VS. abomasum weight(r$_2$) were r$_1$=0.8954$^{**}$ and Y=10.703+3.374X, r$_2$=0.8430$^{**}$ and Y=5.689+4.311X, respectively. 4. Correlation coefficients and regression equation between chest girth VS. abomasum weight(r$_1$), and body weight VS. abomasum weight(r$_2$) were r$_1$=0.8708$^{**}$ and Y=-17.219+1.227X, r$_2$=0.8589$^{**}$ and Y=- 17.616+1.290X, respectively.

• Applied Microscopy
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• v.18 no.2
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• pp.141-152
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• 1988

The developmental processes of the protein body are studied on endosperm cells of Panax ginseng during seed maturation periods. The spherosome, mitochondria, rough endoplasmic reticulum, and ribosome are observed and then are gradually increased in early endosperm cells. Protein body developed from vesicles produced by the rough endoplasmic reticulum and was formed at the enlarged ends of rough endoplasmic reticulum. Also, vacuole-like protein body was observed in associated with rough endoplasmic reticulum. Golgi complex is observed in associated with vacuole and its vesicles containing proteinaceous granules moved and accumulated to the vacuole. Proteinaceous granules are deposited in the spherical or oval shaped vacuole and gradually, vacuole is surrounded by the multi-membranous structure. Rough endoplasmic reticulum, ribosome, Golgi complex, and vacuole are observed in associated with protein body formation.

• The Korean Journal of Zoology
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• v.19 no.4
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• pp.161-170
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• 1976

Since caffeine inhibits the active uptake of Ca by the sarcoplasmic reticulum, the action of caffeine on the fragmented sarcoplasmic reticulum of rabbit skeletal muscle was studied. Caffeine seemed not to bind tightly to the sarcoplasmic reticulum. The determination of sulfhydryl content of the fragmented sarcoplasmic reticulum, however, suggested that caffeine in some unknown manner influences the protein moiety and thereby increases the sulfhydryl content. The inhibition of Ca uptake by caffeine therefore might be considered as due to the result of this change in protein sulfhydryl content.

• The Korean Journal of Physiology
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• v.20 no.2
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• pp.157-164
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• 1986

Since it has been reported that vanadate inhibits $Ca^{++}-ATPase$ activity without affecting $Ca^{++}$ uptake, this study was undertaken to investigate the effects of vanadate on $Ca^{++}-ATPase$ activity and $Ca^{++}$ uptake in the sarcoplasmic reticulum of rat skeletal muscle. The following results were obtained. 1) $Ca^{++}$ activated ATPase activity of the intact sarcoplasmic reticulum was significantly inhibited when vanadate was added to the incubation medium at concentration greater than $10^{-6}\;M$. However $Mg^{++}$-ATPase activity of the intact SR was not affected by vanadate at concentrations ranging from $10^{-7}\;to\;10^{-4}\;M.$ Similarly, $Ca^{++}-ATPase$ activity in sonicated sarcoplasmic reticulum was significantly reduced by vanadate at a concentration $10^{-7}$ M or higher. 2) The uptake of $Ca^{++}$ by isolated sarcoplasmic reticulum was also inhibited by vanadate under the conditions where the turnover rate of $Ca^{++}-ATPase$ was made to increase. These results suggest that the inhibition of $Ca^{++}$ uptake by vanadate may be correlated with that of $Ca^{++}-ATPase$ if experimental conditions are properly set.