Biomaterial Database

Stratum corneum of frog skin: inferences for studies of Na entry and transport pool. 1977

S I Helman, and R S Fisher

Pieces of isolated stratum corneum from frog skins were studied. Preliminary data showed that approximately 56% of the total sodium of split skins was associated with the stratum corneum. In more detailed studies, the sodium space estimated with 22Na and the volume of tissue water were identical, averaging 0.95 mul/cm2. Thus, the stratum corneum contained approximately 0.11 mueq Na+/cm2. Similar determinations of the sucrose, mannitol, and inulin spaces of the stratum corneum gave mean values of 0.84, 2.21, and 1.84 mul/cm2, respectively. Surprisingly, the mannitol and inulin spaces were observed to be at least twice as large as the space occupied by the tissue water, and this can be interpreted to mean that mannitol and inulin bind in appreciable amounts and thus are unsuitable markers of the sodium space. Whereas the kinetics of sodium uptake and washout could be described simply, similar studies for sucrose, mannitol, and inulin were more complex and consistent with appreciable binding of the substances to the stratum corneum.

UI	MeSH Term	Description	Entries
D007444	Inulin	A starch found in the tubers and roots of many plants. Since it is hydrolyzable to FRUCTOSE, it is classified as a fructosan. It has been used in physiologic investigation for determination of the rate of glomerular function.
D008353	Mannitol	A diuretic and renal diagnostic aid related to sorbitol. It has little significant energy value as it is largely eliminated from the body before any metabolism can take place. It can be used to treat oliguria associated with kidney failure or other manifestations of inadequate renal function and has been used for determination of glomerular filtration rate. Mannitol is also commonly used as a research tool in cell biological studies, usually to control osmolarity.	(L)-Mannitol,Osmitrol,Osmofundin
D011894	Rana pipiens	A highly variable species of the family Ranidae in Canada, the United States and Central America. It is the most widely used Anuran in biomedical research.	Frog, Leopard,Leopard Frog,Lithobates pipiens,Frogs, Leopard,Leopard Frogs
D004848	Epithelium	The layers of EPITHELIAL CELLS which cover the inner and outer surfaces of the cutaneous, mucus, and serous tissues and glands of the body.	Mesothelium,Epithelial Tissue,Mesothelial Tissue,Epithelial Tissues,Mesothelial Tissues,Tissue, Epithelial,Tissue, Mesothelial,Tissues, Epithelial,Tissues, Mesothelial
D005110	Extracellular Space	Interstitial space between cells, occupied by INTERSTITIAL FLUID as well as amorphous and fibrous substances. For organisms with a CELL WALL, the extracellular space includes everything outside of the CELL MEMBRANE including the PERIPLASM and the cell wall.	Intercellular Space,Extracellular Spaces,Intercellular Spaces,Space, Extracellular,Space, Intercellular,Spaces, Extracellular,Spaces, Intercellular
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001692	Biological Transport	The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.	Transport, Biological,Biologic Transport,Transport, Biologic
D012867	Skin	The outer covering of the body that protects it from the environment. It is composed of the DERMIS and the EPIDERMIS.
D012964	Sodium	A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.	Sodium Ion Level,Sodium-23,Ion Level, Sodium,Level, Sodium Ion,Sodium 23
D013395	Sucrose	A nonreducing disaccharide composed of GLUCOSE and FRUCTOSE linked via their anomeric carbons. It is obtained commercially from SUGARCANE, sugar beet (BETA VULGARIS), and other plants and used extensively as a food and a sweetener.	Saccharose