• Korean Journal of Environmental Biology
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• v.19 no.1
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• pp.1-6
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• 2001

Many researchers have been studied with guard cell protoplasts and detached epidermis as they think that properly stabilized protoplasts and detached epidermis retain many of the properties of intact guard cells. However, some studies have shown that stomata in detached epidermis behave differently, both quantitatively and qualitatively, from those in the intact leaf. Stomata in the intact leaf are very sensitive to environmental factors such as light, $CO_2$ and osmotic stress, but stomata in detached epidermis are less sensitive to these factors than those in the intact leaf. The clearest evidence to suggest the different response between detached epidermis and intact leaf obtained from the experiments with heavy metal, cadmium. 3-weeks old Commelina. communis was transferred to and grown in Hoagland solution in the presence or absence of 5 mM $Cd^{2+}$ for 4 days. The application of $Cd^{2+}$ showed about 70% inhibition of stomatal conductance when measured at various light intensity (100-1,000 $\mu$mole $m^{-2}s^{-1}). However, stomata in detached epidermis floated on an incubation medium containing 100 $\mu$M $Cd^{2+}$ opened to a degree of about 8.38 fm, but the stomata treated with no cadmium opened to 3.74 ${\mu}{\textrm}{m}$. These results were unexpected as the intact leaf grown in a Hoagland solution containing cadmium showed very negative physiological responses. These results showed that stomata in detached epidermis and in the intact leaf could respond reversely. Therefore, it is possible that we now misunderstand how stomata open in real natural condition.

• Applied Microscopy
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• v.20 no.1
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• pp.1-16
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• 1990

The epidermal tissue of Korean planaria Phagocata vivida(Ijima et Kaburaki) is composed of the simple columnar epithelium. The ventral epidermis of this animals is thinner than the dorsal epidermis and has a furrow in the median line in which dark cell is observed. The clear cells which are electron-lucent are located either side of the dark cells. Those are compactly covered with long cilia. The free surface of the latero-ventral epidermis is tightly contacted with the earth and this epidermal free surface has a great number of short cilia, and a lot of C-type of basophilic granule cell are migrated into the cytoplasm of epithelium from mesenchyme passing through the basement membrane and then this granules are put out of latero-ventral free surface. Dorsal epidermis is thickest among the whole epidermis of these animals and the rhabdite granules are more distributed in dorsal epidermis than in ventral epidermis. According to the cytochemical and ultrastructural research, composed epidermis of this planaria are divided into nine type cells, that is, ciliated columnar epithelium, dark cell, mucous cell, rhabdite-forming cell, sunk round cell, A type, B type, C type and D type of basophilic granule cell.

• Korean Journal of Medicinal Crop Science
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• v.21 no.5
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• pp.342-347
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• 2013

This study was carried out to investigate change of ginsenoside contents according to tissue ratio in ginseng root by age and diameter. The epidermis-cortex and xylem-pith extent, fresh weight, dry weight of ginseng increased with the root age increase. They increased higher in xylem-pith than in epidermis-cortex. The ratio of epidermis-cortex decreased and xylem-pith increased as the main root diameter increased. In case of same diameter, the xylem-pith ratio increased by the increase of root age. The epidermis-cortex ratio was 4 > 5 > 6 years, respectively. The total 10 ginsenosides of epidermis- cortex increased with the root age increase. However, the total ginsenoside of xylem-pith decreased and it was 2~5 times lower than epidermis-cortex. The most of ginsenoside contents existed in epidermis-cortex. The diameter decrease in main root is related to the increase of epidermis-cortex ratio. It leads to increase of ginsenoside contents. In order to select high level of ginsenoside cultivar, it suggested that it should be selected main root having narrow diameter and lower epidermis- cortex ratio.

• Korean Journal of Environmental Biology
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• v.23 no.3 s.59
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• pp.221-227
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• 2005

The effects of light and $CO_2$ on the electrophysiological characteristics of guard cells in the intact leaf and isolated epidermis have been investigated. Fast hyperpolarization of guard cell apoplastic PD in the intact leaf was recorded reaching up to around 7 mV and 20 mV in response to light and $CO_2$. Whenever the experiments were attempted with isolated epidermis, there was no response to light and $CO_2$. In order to determine the influence of the mesophyll cells, the apoplastic PD of guard cells in isolated epidermis was measured in the presence of the mesophyll supernatant or the control medium. The apoplastic PD in isolated epidermis was hyperpolarized to -7mV, changing from -22mV to -29mV at 40 min. But, when isolated epidermis was incubated with the supernatant from mesophyll cells incubated in the light, the apoplastic PD in isolated epidermis was hyperpolarized to -19 mV, changing from -22 mV to -40.5 mV. $CO_2$ also caused a change of 0.1 to 0.3 pH unit in the intact leaf. However, this change was absent in isolated epidermis. A vibrating probe was used to detect the change in electrical currents at the surface of excised intact leaves and isolated epidermis. The reading of excised intact leaves in the dark was $0.5\muA\;cm^{-2},$ remaining steady until illuminated. Light increased the current on the surface of excised leaves to about $0.8\muA\;cm^{-2},$. However, light had no effect in the current on the surface of isolated epidermis. Apoplastic pH changes across the stomatal complex in response to light and dark were measured both in the intact leaves and isolated epidermis over the same time period using pH micro-electrodes. The guard cell wall of intact leaf was acidified to 2.5 pH unit, falling from pH 7.5 to pH 5.0 in the first 10 min. in the light. At the same time the guard cell wall pH of isolated epidermis fell from pH 7.5 to pH 7.0 at 10 min. The guard cell wall pH of isolated epidermis incubated in the mesophyll supernatant fell from pH 7.6 to pH 6.7 at 10 min. Likewise, It could be imagined that an electrical signal, chemicals and hormones propagated from the mesophyll in response to light and $CO_2$ could control a fast stomatal response.

• Archives of Pharmacal Research
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• v.12 no.2
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• pp.143-147
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• 1989

The urea effect on skin permeation of clonidine was investigated to reduce a log time and to increase a permeability. ICR mouse skin and human skin were used and were assumed to be a two-layer membrane consisted of stratum corneum and viable epidermis. The urea acted as a skin denaturant and humectant in the whole epidermis. Also it enhanced the skin permeability of clonidine about 3.5 times. On the other hand, it enhanced the skin permeability by acting as a humectant in the viable epidermis. But the urea effect on the whole epidermis was shown to be greater than that on the viable epidermis. Therefore, it was found that the effect of urea was greater on the stratum corneum than the viable epidermis. Variation of enhancing effect according to the concentration of urea was not found in the range of 1% to 20%.

• Journal of Plant Biology
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• v.39 no.3
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• pp.189-195
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• 1996

The major cuticular components have been shown to be synthesized in the epidermis. Therefore, cloning of epidermis-specific genes could yield information to be used to isolate and characterize the enzymes involved in the cuticle biosynthesis. A subtractive cDNA library was prepared from Senecio odorus in which epidermis-specific cDNAs were enriched. Differential screening of the library using epidermal and non-epidermal probes revealed two cDNAs. One of them designated epi425 was identified, based on the sequence homology, as a member of a new class in the LTP gene family and the other clone designated epi23 as a gene encoding an aldehyde decarbonylase. Northern blot analyses showed that epi425 and epi23 cDNAs hybridized with a transcript of about 600 and 2, 100 nucleotides, respectively, from the epidermis but not from the non-epidermal tissues. Further characterization of these clones will provide more information on the mechanism of the cuticle biosynthesis.

• Journal of Pharmaceutical Investigation
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• v.19 no.1
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• pp.39-46
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• 1989

The clonidine transport mechanism through the skin was investigated with assumptions that epidermis is heterogeneous and two-layer membrane. Immobilization of clonidine was not found in stratum corneum but in viable epidermis. The sorption in the viable epidermis agreed with the dual sorption theory. Diffusion coefficient in stratum corneum was five order magnitude less than that in viable epidermis. In viable epidermis, the ratio of true diffusivity to apparent diffusivity increased initially then decreased as a function of clonidine concentration, and the true diffusivity was always larger than the apparent diffusivity.

• Animal cells and systems
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• v.12 no.2
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• pp.85-91
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• 2008

Structure and mucosubstance histochemistry in the epidermis of five teleostean species, i. e., spotty belly, Agrammus agrammus, devil stinger, Inimicus japonicus, stone fish, Erosa erosa, cubed snailfish, Liparis tessellatus, and Japanese bluefish, Scombrops boops were investigated. The epidermis of five species studied is composed of three layers: superficial, middle, and basal layer. The superficial layer is comprised of rather flattened cells. Mucous cells, the type commonly found in fishes are completely lacking in the epidermis of devil stinger, stone fish, and cubed snailfish. The epidermis of devil stinger and stone fish have multicellular glands which do not have mucosubstances. The skin surface of them is covered with mucous layer. The superficial cells in the epidermis of devil stinger, stone fish, and cubed snailfish are mucus-secreting cells. The composition and the amount of the mucosubstances vary in species and body regions. The mucous layer on the skin surface and superficial epidermal cells of devil stinger contain a mixture of neutral and acidic(sulfated and nonsulfated) mucosubstances. In stone fish, the mucous layer has acidic(sulfated and non-sulfated) mucin and the superficial epidermal cells contain neutral mucin. In cubed snailfish, the type of epidermal mucosubstances is identified as a mixture of neutral and acidic(non-sulfated) mucin. The mucous cells of the epidermis in spotty belly and Japanese bluefish contain neutral mucin.

• Toxicological Research
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• v.5 no.2
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• pp.89-96
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• 1989

Rapid and complete epidermal-dermal separation procedure were determined in neonatal rat skin by light microscopic observation and by compairing enzyme activities in the separated epidermis. Microscopic appearance demonstrated the at four different separation procedures used in the study resulted in good separation of epidermis from dermis` heating method (i.e., immersion in 55C water for 30 sec, followed by immersion in 0-4C water) and microwave irradiation for 10 sec were saving time.

• Applied Microscopy
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• v.28 no.3
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• pp.307-314
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• 1998

The author has undertaken this study for demonstrating the relationship between keratinization and proliferation as well as remodeling of epidermis. Healthy ICR strain male mice, weighing about $20\sim25gm$, were used as experimental animals. Under the general anesthesia with ether the skins of experimental animals were subjected to a dorsal, transverse, full-thickness incision with 0.5cm in length, and removed them on 3rd day, 7th day and 2nd week after operation Specimens were prepared for electron microscopic study. The results obtained were as follows: The epidermis of 3rd day group is made up of $7\sim8$ keratinocytes. The new epidermal cells are grown beneath the necrotic tissue. Keratohyaline granules (KHGs) are visible in some granular cells. Various sited-KHGs are seen in granular layer cell, and in spinous cell ribosomes, tonofilaments and lamellar granules are seen. The epidermis of 7th day group is made up of $7\sim8$ keratinocytes. Numerous KHGs are seen in granular layer cells. KHGs are located in granular layer cells as well as spinous layer cells. The epidermis of End week group is composed of one-layered basal cell and $1\sim2$ layered superficial cells. Various sized-KHGs are observed in granular layer cells. The results of the present study suggest that as the epidermis should be keratinized during proliferation and remodeling process, so keratinization of the epidermis would play a major role of wound healing process.