• The Korean Journal of Physiology
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• v.26 no.2
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• pp.113-122
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• 1992

It is well known that chromaffin cells of adrenal medulla secrete catecholamine in response to sympathetic nerve activation and the influx of $Ca^{2+}$ through the voltage dependent $Ca^{2+}$ channels (VDCC) in the cell membrane do a major role in this secretory process. In this study, we explored the effect of divalent cations on VDCC of rat chromaffin cells. Rat (Sprague-Dawley rat, 150-250 gm) chromaffin cells were isolated and cultured. Standard giga seal, whole cell recording techniques were employed to study $Ca^{2+}$ current with external and internal solutions that could effectively isolate VDCC currents $(NMG\;in\;external\;and\;TEA\;and\;Cs^{2+}\;in\;internal\;solution)$. The voltage dependence and the inactivation time course of VDCC in our cells were identical to those of bovine chromaffin cells. A persistent inward current was first activated by depolarizing step pulse from the holding potential (H.P.) of -80 mV to -40 mV, increased to maximum amplitude at around +10 mV, and became smaller with progressively higher depolarizing pulses to reverse at around +60 mV. The inactivation time constant $(\tau)$, fitted from the long duration test potential (2 sec) was $1295.2{\pm}126.8$ msec $(n=20,\;1\;day\;of\;culture,\;mean\;{\pm}S.E.M.)$ and the kinetic parameters were not altered along the culture duration. Nicardipine $(10\;{\mu}M)$ blocked the current almost completely. Among treated divalent cations such as $Cd^{2+},\;Co^{2+},\;Ni^{2+},\;Zn^{2+}\;and\;,Mn^{2+},\;Cd^{2+}$ was the most potent blocker on VDCC. When the depolarizing step pulse from -80 mV to 10 mV was applied, the equilibrium dissociation constant $(K_d)$ of $Cd^{2+}\;was\;39\;{\mu}M,\;K_d\;of\;Co^{2+}\;was\;100\;{\mu}M\;and\;K_d\;of\;Ni^{2+}];was];780{\mu}M.$ The principal findings of this study are as follows. First, the majority of $Ca^{2+}$ channels in rat chromaffin cells are well classified to L-type $Ca^{2+}$ channel in the view of kinetics and pharmacology. Second, all divalent cations tested could block the $Ca^{2+}$ current and the most potent blocker among the tested was $Cd^{2+}$.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.1
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• pp.1-12
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• 2006

Pleomorphic adenoma is the most common benign tumor in salivary glands, and occurred in frequency of 60% in parotid gland tumors, and 50% in submandibular gland tumors, and 25% in sublingual gland tumors. Histopathologically, pleomorphic adenoma is composed of epithelial cells and mesenchymal tissues, and called 'mixed tumor' because of morphological divergency. The cell structures of luminal area are composed of polyhedral and cuboidal secretory epithelial cells and modified myoepithelial cells around it, and mesenchymal tissue is composed of some myoepithelial cells and stromal tissue. In stromal tissue, myxoid change, chondroid change, or hyalinization can be seen even if bone tissue. In many studies, tumor cells of pleomorphic adenoma containing modified myoepithelial cell participate in synthesis of glycosaminoglycans. In this study, tissue sample of pleomorphic adenoma of human salivary gland were obtained from 20 surgical specimens, and all specimens were routinely fixed in 10% formalin and embedded. Serial 4-8${\mu}m$ thick sections were cut from paraffin blocks. The histopathologic evaluation was done with light microscopy. And, with immunohistochemical staining, characteristics of glycosaminoglycan were observed. And, for biochemical analysis of glycosaminoglycan, isolation of crude glycosaminoglycan from tumor tissue and immuno-blot analysis were carried out. With transmission electromicroscopy, tumor cells and biologic behavior of pleomorphic adenoma were observed with distribution and expression of glycosaminoglycan in tumor cells, The results were obtained as follows: 1. In immunohistochemical study, chondroitin 4-sulfate is highly postively stained in myxoid stromal tissue, and chondroitin 6-sulfate is highly positively stained in chondroid mesenchymal tissue, both glycosaminoglycans are positively stained in non-luminal cell of ductal area. 2. Dermatan sulfate and keratan sulfate is positively stained in periductal non-luminal tumor cells. 3. In immunohistochemical study, heparan sulfate is weakly stained in luminal cells and non-luminal cells around duct, and chondroid mesenchymal tissue. 4. In transmission electromicroscopic view, the tumor cells are composed of modified myoepithelial cells, and contain many microfilaments and well developed rough endoplasmic reticulum. 5. In Immuno-Blot analysis, the expression of glycosaminoglycans is expressed mostly in chondroitin 6-sulfate and chondroitin 4-sulfate. From the results obtained in this study, tumor cells of pleomorphic adenoma are composed of modified myoepithelial cells, and glycosaminoglycans of chondroitin 4-sulfate and chondroitin 6-sulfate mostly participate in the development of pleomorphic adenoma, but dermatan sulfate, keratan sulfate and heparan sulfate glycosaminoglycans were expressed variably.

• Applied Microscopy
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• v.22 no.2
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• pp.15-29
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• 1992

The gallbladder is known to have the function of the storage and the concentration of the bile produced by the liver. This function is carried out by the removal of water and inorganic electrolytes. Extrahepatic cholestasis or the impairment of excretion of the bile leads to the distension and loss of the function of the gallbladder. The purpose of this study was to examine the ultrastructural characteristics of the normal gallbladder epithelial cells, and their structural changes induced by the ligation of common bile duct of the rabbit. Common bile duct ligation was performed under ether anesthesia. The rabbits were sacrificed on the 1st, 3rd, 5th, 7th and 14th day, respectively after operations. The tissue blocks of the gallbladder were fixed in 2.5% glutaraldehyde-1.5% paraformaldehyde prior to fixation in 1% osmium tetroxide, and embedded in the araldite mixture, and observed with JEM 100 CX-II electron microscope. The results were as follows: 1. The normal gallbladder epithelium of adult rabbit demonstrated two cell types, the ordinary epthelial cell and the dark cell. The dark cells have electron dense cytoplasm, and were found much infrequently, whereas ordinary epthelial cells were found quite numerous. 2. The ordinary epthelial cells of normal gallbladder were provided with the regular microvilli at the free surface and the images of pinocytotic activities in the apical cytoplasm, and exhibit highly convoluted lateral surfaces with elaborated microfolds. These figures of the cells suggest that they are resorptive in functional activity. 3. In the early stages (1st, 3rd, 5th day groups) following the ligation, the apical cytoplasm of some cells is protruding from the free surface and lost their microvilli. Numerous mucous granules filled in the apical and supranuclear cytoplasm compactly. 4. In the late stages (7th, 14th day groups) following the ligation, many light cells containing mumerous mucous granules are seen, between the ordinary epthelial cells. Mucous granules are fused each other, and are discharged into the lumen from the apical cytoplasm. The lateral membranes are straight or undulating without any interdigitations. From the above results, it was concluded that in the cholestasis induced by the common bile duct ligation, there is a tendency for the mucosal epithelium of the rabbit gallbladder to have secretory rather than an absorptive function.

• Korean Journal of Plant Resources
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• v.8 no.3
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• pp.237-246
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• 1995

In this study, the callus was induced and regenerated from the immature embryo and ultrastructural characteristics of developmental stages in Citrus junos SIEB, were investigated. The yellowish callus was induced by 5 to 6 week of culture of citrus. In proliferation callus after 6 weeks of culture, large vacuole was formed by fusion between adjacent small ones. In the non-embryogenic callus cultured for 12weeks, re-differentiated cells of callus showed the large nucleus with globular nucleus and amyloplast with large size of starches. In the embryogenic callus cltured for 14-16 weeks, the active exocytosis occurred in cells, secretory vesicles appeared on cell membrane and small particles from cytoplasm were released to intercelluar space. In the embryogenic callus cultured for 24 weeks, a sperical type of chloroplast bounded on cytoplasm by double membrane and typical grana was dispersed equally among matrix. In the normal plantlet after 26 weeks of culture, a lot of vessels and companion cells apperaed in the leaf cell of plantlet. In the normal plantlet after 30 weeks of culture, the immature leaf showed many small companion cells, sieve tubes and central vacuole. Also, the secondary vacuole protruded into the central vacuole and elongated chloroplasts near plasma membrane. In the matured plant habituated on the soil, palisada tissue composed of orderly arranged cells contained the nucleus in the center of the cell and large vacuoles on either side of the nucleus.

• Korean Journal of Veterinary Research
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• v.37 no.1
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• pp.87-101
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• 1997

The development of trachea in fetuses on 60, 90 and 120 days of gestation and neonates of Korean native goats was investigated by microscopy and scanning and transmission electron microscopy. The results were summarized as follows; Light microscopic studies: 1. In the 60-day-old fetuses, the tracheal walls were differentiated and divided into four layers of the mucosa, submucosa, muscle and cartilage, and adventitia. The tracheal epithelium is composed of stratified ciliated columnar epithelium at 60- and 90-day-old fetuses while the epithelium observed at 120-day-old fetuses was pseudostraified ciliated colummar epithelium. 2. In the 90-day-old fetuses, tracheal glands extended into the submucosa and peripheral area of the tracheal cartilage. The blood vessels were observed in the submucosa and adventitia. The elastic and collagenous fibers were observed in the tracheal walls. 3. In the neonates, the tracheal walls consisted of mucosa with well-developed folds, submucosa, tracheal glands, muscle and cartilage, collagenous and elastic fibers, and adventitia, which were more developed than those of 120-day-old fetuses. The tracheal epithelium was developed as that in adults. Scanning electron microscopic studies: 4. In the 60-day-old fetuses, most of tracheal epithelial cells were nonciliated but short microvilli were sporadically observed on the luminal surface. On rare occasions, a few cells have solitary cilium. 5. In the 90-day-old fetuses, the ciliated cells appeared increasingly and cilia elongated longer than those of 60-day-old fetuses. 6. In the 120-day-old fetuses, the nonciliated cells covered with microvilli in dome-shape were barriered by thick carpet of cilia. The nonciliated cells also have many papillary projectons on the apical surface. 7. In the neonates, the nonciliated cells in tracheal epithelium were covered compactly with numerous cilia, and many secretory droplets were found on the cilia. Transmission electron microscopic studies: 8. In the 60-day-old fetuses, nonciliated cells of the tracheal epithelium contain large amounts of glycogen granules in the supernuclear and subnuclear areas meanwhile a few cell organelles were formed. Cilia were well formed along the apical cell membranes of the ciliated cells. Also found in the ciliated cells were basal corpuscles, mitochondria and short chains in granular endoplasmic reticulum(GER). Between the epithelial cells presented were well-defined junctional complex with zonula occludens and desmosomes. The nuclei were variable in size and shape. The more developed nucleoli were observed conspicuosly. 9. In the 90-day-old fetuses, nonciliated cells contained large glycogen granules. Accumulated glycogen granules were observed in the subnuclear and supranuclear portion of the cytoplasm. A few short microvilli were covered with glycocalyx. Ciliated cells contained numerous mitochondria and short chains of GER. 10. In the 120-day-old fetuses, the ciliated cells contained numerous mitochondria, abundant short chains of GER and nucleoli. Nonciliated cells contained some Golgi complex and mitochondria. The cell borders were well-defined and distinct junctional complex with zonula occludens, desmosomes, and interdigitorum. 11. In the neonates, well-developed goblet cells were observed in the tracheal epithelium. Ultrastructures of ciliated and nonciliated cells on the tracheal epithelia were similar in pattern as those in adults.

• Biomedical Science Letters
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• v.19 no.2
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• pp.158-163
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• 2013

Cholestatic liver is associated with hepatic inflammation and elevated proinflammatory cytokines. Recent studies indicate that certain cytokines can modulate bile secretion. In the present study, we have examined the role of interleukin (IL-2) on the bile secretion by a combination of study models. To examine the relevance of IL-2 on bile secretion, the expression of IL-2 and IL-2 receptor (IL-2R) of isolated normal and bile duct ligated (BDL) rats cholangiocytes was first measured by RT-PCR. In BDL rats, the expression of IL-2 and IL-2R was significantly increased compared with normal rats. To study the effect of IL-2 on bile secretion, bile flow was measured in normal and BDL rats. At the level of cholangiocytes, secretory responses of isolated bile duct unit (IBDU)s were quantified by videomicroscopy. The administrations of IL-2 had no significant effect on basal bile secretion in normal and BDL rats. There was no significant effect of IL-2 on basal bile ductular secretion as evidenced by no significant difference in luminal area of the IBDUs perfusedwith 100 pM of IL-2 from those of albumin carrier control. However, the secretin-stimulated bile ductular secretion was significantly (P < 0.01) inhibited by $34{\pm}4%$ (normal, n = 12), $21{\pm}5.3%$ (BDL 2 wk, n = 12) and $15{\pm}5.2%$ (BDL 4 wk, n = 12) with the co-administration of IL-2. As with other cytokines, physiologically relevant concentration of IL-2 can significantly inhibit secretin-stimulated bile ductular secretion. These findings support the important roles of cytokines in modulating bile secretion and may contribute to the cholestasis seen in cholestatic liver diseases.

• Journal of Haehwa Medicine
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• v.15 no.1
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• pp.141-160
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• 2006

The obtained results are summarized as follows 1. New findings are reporting year by year as for the study related to Anti-inflammatory mechanism of Bee Venom therapy. 2. The Anti-inflammatory effect of Bee Venom therapy is achieved through counterirritation, stimulations to adrenal cortex, immuno-regulation, antioxidation, removal of free radicals, modulation of AGP gene induction. 3. The chief components of Bee Venom related to Anti-inflammatory effect are Melittin, MCD peptide, Apamin, Adolapin etc. 4. Melittin binds to secretory phospholipase A2 and inhibits its enzymatic activity. 5. Melittin blocks neutophil O2-production. 6. MCD peptide(Peptide 401) stimulates the mast cell secrets histamine, Anti-inflammatory effect caused by this is 'conterirritation'. 7. Melittin & Apamin have an anti-inflammatory effect by inducing cortisone secretion. 8. MCD peptide & Apamin increase immunologic fuction by stimulating hypophysis & adrenal cortex and have an anti-inflammatory effect by inhibiting synthesis of prostaglandin from arachidonic acid. 9. Adolapin have an anti-inflammatory effect by inhibiting COX. 10. Bee Venom have an anti-inflammatory effect by suppressing AGP($\alpha$-acid glycoprotein). 11. Bee Venom have an anti-inflammatory effect by inhibiting NO, iNOS, PLA2, COX-2, TNF-$\alpha$, IL-1, NF-${\kappa}B$, MAP kinase.

• Applied Microscopy
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• v.18 no.2
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• pp.153-166
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• 1988

The fine structure of the salivary glands of the pine moth, Dendrolimus spectabilis Butler, at the last larval period is observed using light and electron microscopes. The moths have single paired tubular salivary glands which openings are connected to the oral cavity through the upper jaw. By the external morphology and its functions, the glands are subdivided into three regions which are anterior reabsorptive region, middle storage region and posterior secretory region. Along the inner canal of the salivary gland two columns of the large glandular cells are connected each other and oriented to ring-like forms. By this cellular orientation, the glands have long and large tubular structure. From anterior to posterior region large nuclei of the glands are ramified like twigs of the tree, and in the cytoplasm of the cell numerous mitochondria and vacuoles are seen. Moreover, basal plasma membranes of the gland cells are heavily infolded. The anterior region of the glands keeps several characteristics related to the reabsorption of the material from the inner cavity to the glandular cells whereas, main salivary material is synthesized and secreted through the long and convoluted posterior region. The apical plasma membranes of the cells are the most heavily invaginated at the posterior regoin, but trachea and tracheoles are distributed only at the middle and posterior regions. In the cytoplasm of the middle region Golgi complexes appeared at the vicinity of the vesicles, and at the posterior region of the salivary glands multivesicular bodies are also observed.

• Applied Microscopy
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• v.20 no.1
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• pp.105-119
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• 1990

In order to know the morphological characteristics and changes according to the developmental stage, the comparative observations have been studied by light and electron microscope on the midgut(gastric caecum, stomach) of the grasshopper(Oxya sinuosa Mistshenko). The results obtained are summarized as follow : In light microscopic level, the cuboidal shaped cells of the gastric caecum in the 5th instar nymph are differentiated the columnar epithelium in the adult. A number of pigment granules are appeared in the gastric caecum of the 5th instar nymph, however the pigment granules were absent in the adult. Indistinct or undifferentiated folds of the epithelial layer were appeared in the 5th instar nymph, whereas the well-developed folds were appeared the gastric caecum in the adult. The well-developed muscular layers are seen in the 5th instar numph, however in the adult the muscular layers are appeared thin or a few layers. In electron microscopic level, in the midgut epithelium, a number of well-developed rER, a few lipid droplets, multi vesicular bodies, small vesicles and glycogen granules were found. Two types of the pigment granules in the gastric caecum of the 5th instar nymph were appeared, whereas the whorl-membrane, a few secretory granules and one type of the gastro-entero-endocrine cell were found in the adult midgut. The light and dark cells could be distinguished in the stomach epithelim of the 5th instar nymph.

• Molecules and Cells
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• v.41 no.4
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• pp.290-300
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• 2018

Using an in vitro model of intestinal organoids derived from intestinal crypts, we examined effects of indole-3-carbinol (I3C), a phytochemical that has anticancer and aryl hydrocarbon receptor (AhR)-activating abilities and thus is sold as a dietary supplement, on the development of intestinal organoids and investigated the underlying mechanisms. I3C inhibited the in vitro development of mouse intestinal organoids. Addition of ${\alpha}$-naphthoflavone, an AhR antagonist or AhR siRNA transfection, suppressed I3C function, suggesting that I3C-mediated interference with organoid development is AhR-dependent. I3C increased the expression of Muc2 and lysozyme, lineage-specific genes for goblet cells and Paneth cells, respectively, but inhibits the expression of IAP, a marker gene for enterocytes. In the intestines of mice treated with I3C, the number of goblet cells was reduced, but the number of Paneth cells and the depth and length of crypts and villi were not changed. I3C increased the level of active nonphosphorylated ${\beta}$-catenin, but suppressed the Notch signal. As a result, expression of Hes1, a Notch target gene and a transcriptional repressor that plays a key role in enterocyte differentiation, was reduced, whereas expression of Math1, involved in the differentiation of secretory lineages, was increased. These results provide direct evidence for the role of AhR in the regulation of the development of intestinal stem cells and indicate that such regulation is likely mediated by regulation of Wnt and Notch signals.