• Archives of Pharmacal Research
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• 제12권2호
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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%.

• 동의생리병리학회지
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• 제16권6호
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• pp.1110-1116
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• 2002

The skin(皮膚) separates epidermis(皮) and dermis(膚) in Oriental medicine. epidermis and hair come from ectoderm as dermis comes from mesoderm in embryology. Epidermis and hair belong to the Metal(金) and dermis belongs to the Earth(土) in Oriental medicine. The lung is related to the skin and hair. The skin surface is nourished by the essence from the lung, and the. lung has the function of sending wei-qi(衛氣.: defensive Energy) to the skin surface to guarantee body resistance. The skin takes nourishment from blood(血) and express by qi(氣). The supply of nutrients to the lung and skin relies on the function of the spleen, pancreas and subcutis. Flaming of the heart fire may scorch the essence of the lung-metal, inducing dermatosis.

• Applied Microscopy
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• 제52권
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• pp.13.1-13.6
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• 2022

Microscopic structure of skin in two amphibious mudskipper fish; Boleophthalmus dussumieri Valenciennes, 1837 (B. dussumeri) and Periophthalmus waltoni Koumans, 1941 (P. waltoni) were investigated in relation to their lifestyle. The general structure of skin is the same among the two species. Epidermis in B. dussumeri was thicker significantly than P. waltoni. The dermal bulges were only well developed in the skin of B. dussumeri. Mucous cells were absent in the epidermis of P. waltoni but present in B. dussumeri. Both B. dussumeri and P. waltoni have well-developed swollen middle cells as a shared epidermal feature. The thickness of the middle cell layer of the epidermis in B. dussumeri was significantly greater than in P. waltoni. Capillaries in the dorsal and ventral parts of the body are more closely distributed to the epidermal surface in P. waltoni than in B. dussumeri. The diffusion distance in the dorsal epidermis of P. waltoni was less than that in the ventral epidermis of B. dussumeri. A comparative examination of the skin of mudskipper species suggests that, due to the more terrestrial lifestyle adopted by P. waltoni, the skin contributes more to respiration.

• Animal cells and systems
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• 제4권4호
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• pp.315-318
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• 2000

Structure of the skin in amphibious fish, Periophthalmus modestus, was described in relation to cutaneous respiration. The epidermis has no gland cell. The epidermis consists of three regions: outermost layer of one to five layers of flattened epithelial cells, middle layer of swollen epithelial cells instead of glandular cells and stratum germinativum of cuboidal cells. There are numerous blood capillaries in the outermost layer of the epidermis and diffusion distance between the blood of capillaries and the epidermis is about 1.4 Um. The middle layer of the epidermis appears to be a web-like structure due to the swollen epithelial cells. The stratum germinativum has a well-developed lymphatic space containing lymphocytes. There are numerous blood capillaries and elliptical area with acid mucopolysaccharides in stratum laxum of the dermis. The skin of Periophthalmus modestus may be an accessory respiratory organ for oxygen uptake during terrestrial or aquatic life.

• Animal cells and systems
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• 제11권2호
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• pp.155-160
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• 2007

The skin of the Korean bullheads, Pseudobagrus brevicorpus and P. koreanus, is composed of epidermis, dermis and subcutis. The epidermis has three layers, the outermost layer, middle layer and stratum germinativum. The epidermis consists of two types of gland cells, an unicellular mucous cell of sulfomucin and a large club cell having sometimes two nuclei. The epidermis has numerous intraepithelial blood vessels in P. brevicorpus but not at all in P. koreanus. Lymphatic spaces containing lymphocytes are well developed in mainly the stratum germinativum. The dermis lacks scales and consists mostly of bundles of coarse collagen fibers. The collagen bundles are arranged in parallel to each other in the dorsum and lateral region toward the dorsum, but vertically at intervals in the abdomen and lateral region toward the abdomen. Considering this unique skin structure, the two species are likely to exercise cutaneous respiration as a dual respiratory system to overcome hypoxic conditions which frequently occurs in their habitats.

• Journal of Pharmaceutical Investigation
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• 제19권1호
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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.

• Journal of Pharmaceutical Investigation
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• 제32권3호
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• pp.161-164
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• 2002

Gentisic acid is a skin-whitening agent which inhibits the tyrosinase activity, an essential enzyme in the process of biological synthesis of melanin. Since melanin is synthesized in melanocytes located between the viable epidermis and dermis layer, drug amount delivered into the epidermis/dermis layer can provide valuable information for the biological effect of skin-whitening agents. The purpose of this study was to prepare the gentisic acid patches with 2% dodecylamine as enhancer, and to observe the in vitro skin permeation and in vivo skin deposition of gentisic acid. Gentisic acid in DuroTak 87-2510 patch formulation permeated across hairless mouse skin at the rate of $40.79\;{\mu}g/cm^2/hr$. In vivo study showed that the gentisic acid amount in both the stratum corneum and the viable epidermis/dermis increased with the increase of application time. The amount of gentisic acid in the stratum corneum was higher than that in the epidermis/dermis layer, and was expected to provide a reservoir effect even after removing the patches. Thus, the patch formulation seems to be useful for the topical delivery of skin-whitening agent into the epidermis/dermis layer, the target site.

• Archives of Plastic Surgery
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• 제32권3호
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• pp.357-362
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• 2005

The aim of this study is to elucidate the effect of keratinase on epidermis of rat skin. Twenty-five male Sprague-Dolly rats were used. The hair on the back were removed and $2{\times}2cm$ area was marked. The rats were divided five groups; 1) Control group(Co), 2) Cleansing gel group(Cl), 3) Cleansing gel+keratinase group, 4) Exfoliant gel group(Ex), and 5) Exfoliant gel+ keratinase group(Ex+K). The solutions were applied to the back area twice a day for five days. On fifth day, the skins were harvested, fixed and prepared for histologic sections. The thickness of keratin layer, living epidermis, dermis, and cell layer number of living epidermis were measured. In the group containing keratinase(Cl+K, Ex+K), the thickness of keratin layer and living layer were thinner than other groups. However, there were no significant differences of the cell layer number of living epidermis and thickness of the dermis among the five groups. We think the keratinase may have the effect thinning the keratin layer as well as the thickness of living epidermis, without effecting the living cell and dermal component. The keratinase containing soap may be of benefit to remove the excess keratin layers in human.

• Animal cells and systems
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• 제7권1호
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• pp.43-47
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• 2003

The skin of the eel goby, Odontamblyopus lacepedii, consists of epidermis, dermis and subcutis. The epidermis has three layers: the outermost layer, middle layer and stratum germinativum. The outermost layer is composed of polygonal cells or rather flattened cells, and mucous gland cells of acid mucopolysaccharides. The middle layer consists mainly of swollen small or voluminous epidermal cells and shows a web-shaped structure. The thickness of the epidermis depends on the various sizes and the number of layers of the swollen cells. Well-developed lymphatic spaces containing lymphocytes exist in the stratum germinativum and small scales are embedded in the dermis. A large number of blood capillaries are present just below the basement membrane, and a definite area giving AB and PAS positive was present between the basement membrane and scales, Taste buds ave distributed on surface of the epidermis at intervals. Considering the structural features of the skin, it may be considered that O. lacepedii is more likely to be related to cutaneous respiration as a dual respiratory system.

• Animal cells and systems
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• 제12권2호
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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.