Biomaterial Database

Urea uptake and translocation in toad urinary bladder: the effect of antidiuretic hormone. 1977

M Parisi, and O Candia

The uptake of C14-urea into everted and noneverted bladder sacs was compared, over short time periods (up to 2 min), with the transepithelial urea fluxes. This method allowed the study of the time course of urea uptake and distribution, while previously this problem was only studied in steady-state conditions. When mucosal uptake was studied no accumulation of C14-urea inside the tissue was observed, indicating that the mucosal border could be the limiting step. Comparative studies of urea and inulin uptake from the serosal side showed that urea equilibrated with the water epithelial cells in less than 30 sec. This accumulation suggested again that the mucosal border is an effective barrier for urea translocation. The kinetics of the increase in urea permeability induced by antidiuretic hormone was also studied and it was similar (T1/2:4.3 min) to the kinetics of the increase in water permeability induced by the hormone (T1/2:5.6 min). A strong parallelism was also observed between the time course of the increases in water and urea permeabilities induced by medium hypertonicity (T1/2 25 and 26 min, respectively). The values obtained for the permeability coefficient ktrans), either at rest or under ADH were similar to those previously reported employing steady-state techniques (28+/-8 and 432+/-25 cm-sec-1-10(-7), respectively).

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.
D009092	Mucous Membrane	An EPITHELIUM with MUCUS-secreting cells, such as GOBLET CELLS. It forms the lining of many body cavities, such as the DIGESTIVE TRACT, the RESPIRATORY TRACT, and the reproductive tract. Mucosa, rich in blood and lymph vessels, comprises an inner epithelium, a middle layer (lamina propria) of loose CONNECTIVE TISSUE, and an outer layer (muscularis mucosae) of SMOOTH MUSCLE CELLS that separates the mucosa from submucosa.	Lamina Propria,Mucosa,Mucosal Tissue,Muscularis Mucosae,Mucous Membranes,Membrane, Mucous,Membranes, Mucous,Mucosae, Muscularis,Mucosal Tissues,Propria, Lamina,Tissue, Mucosal,Tissues, Mucosal
D001743	Urinary Bladder	A musculomembranous sac along the URINARY TRACT. URINE flows from the KIDNEYS into the bladder via the ureters (URETER), and is held there until URINATION.	Bladder,Bladder Detrusor Muscle,Detrusor Urinae,Bladder Detrusor Muscles,Bladder, Urinary,Detrusor Muscle, Bladder,Detrusor Muscles, Bladder
D002024	Bufo marinus	A species of the true toads, Bufonidae, becoming fairly common in the southern United States and almost pantropical. The secretions from the skin glands of this species are very toxic to animals.	Rhinella marina,Toad, Giant,Toad, Marine,Giant Toad,Giant Toads,Marine Toad,Marine Toads,Toads, Giant,Toads, Marine
D002250	Carbon Radioisotopes	Unstable isotopes of carbon that decay or disintegrate emitting radiation. C atoms with atomic weights 10, 11, and 14-16 are radioactive carbon isotopes.	Radioisotopes, Carbon
D002463	Cell Membrane Permeability	A quality of cell membranes which permits the passage of solvents and solutes into and out of cells.	Permeability, Cell Membrane
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
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
D014508	Urea	A compound formed in the liver from ammonia produced by the deamination of amino acids. It is the principal end product of protein catabolism and constitutes about one half of the total urinary solids.	Basodexan,Carbamide,Carmol
D014667	Vasopressins	Antidiuretic hormones released by the NEUROHYPOPHYSIS of all vertebrates (structure varies with species) to regulate water balance and OSMOLARITY. In general, vasopressin is a nonapeptide consisting of a six-amino-acid ring with a cysteine 1 to cysteine 6 disulfide bridge or an octapeptide containing a CYSTINE. All mammals have arginine vasopressin except the pig with a lysine at position 8. Vasopressin, a vasoconstrictor, acts on the KIDNEY COLLECTING DUCTS to increase water reabsorption, increase blood volume and blood pressure.	Antidiuretic Hormone,Antidiuretic Hormones,beta-Hypophamine,Pitressin,Vasopressin,Vasopressin (USP),Hormone, Antidiuretic,beta Hypophamine