A specialized barrier in the kidney, consisting of the fenestrated CAPILLARY ENDOTHELIUM; GLOMERULAR BASEMENT MEMBRANE; and glomerular epithelium (PODOCYTES). The barrier prevents the filtration of PLASMA PROTEINS.

Highly differentiated epithelial cells of the visceral layer of BOWMAN CAPSULE of the KIDNEY. They are composed of a cell body with major CELL SURFACE EXTENSIONS and secondary fingerlike extensions called pedicels. They enwrap the KIDNEY GLOMERULUS capillaries with their cell surface extensions forming a filtration structure. The pedicels of neighboring podocytes interdigitate with each other leaving between them filtration slits that are bridged by an extracellular structure impermeable to large macromolecules called the slit diaphragm, and provide the last barrier to protein loss in the KIDNEY.

The layer of EXTRACELLULAR MATRIX that lies between the ENDOTHELIUM of the glomerular capillaries and the PODOCYTES of the inner or visceral layer of the BOWMAN CAPSULE. It is the product of these two cell types. It acts as a physical barrier and an ion-selective filter.

A cluster of convoluted capillaries beginning at each nephric tubule in the kidney and held together by connective tissue.

A sucrose polymer of high molecular weight.

The volume of water filtered out of plasma through glomerular capillary walls into Bowman's capsules per unit of time. It is considered to be equivalent to INULIN clearance.

A condition characterized by severe PROTEINURIA, greater than 3.5 g/day in an average adult. The substantial loss of protein in the urine results in complications such as HYPOPROTEINEMIA; generalized EDEMA; HYPERTENSION; and HYPERLIPIDEMIAS. Diseases associated with nephrotic syndrome generally cause chronic kidney dysfunction.

The presence of proteins in the urine, an indicator of KIDNEY DISEASES.

The presence of albumin in the urine, an indicator of KIDNEY DISEASES.

A clinicopathological syndrome or diagnostic term for a type of glomerular injury that has multiple causes, primary or secondary. Clinical features include PROTEINURIA, reduced GLOMERULAR FILTRATION RATE, and EDEMA. Kidney biopsy initially indicates focal segmental glomerular consolidation (hyalinosis) or scarring which can progress to globally sclerotic glomeruli leading to eventual KIDNEY FAILURE.

Property of membranes and other structures to permit passage of light, heat, gases, liquids, metabolites, and mineral ions.

Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.

Pathological processes of the KIDNEY or its component tissues.

Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.

Fluorescent probe capable of being conjugated to tissue and proteins. It is used as a label in fluorescent antibody staining procedures as well as protein- and amino acid-binding techniques.

KIDNEY injuries associated with diabetes mellitus and affecting KIDNEY GLOMERULUS; ARTERIOLES; KIDNEY TUBULES; and the interstitium. Clinical signs include persistent PROTEINURIA, from microalbuminuria progressing to ALBUMINURIA of greater than 300 mg/24 h, leading to reduced GLOMERULAR FILTRATION RATE and END-STAGE RENAL DISEASE.

A major protein in the BLOOD. It is important in maintaining the colloidal osmotic pressure and transporting large organic molecules.

Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.

Creatinine is a waste product that's generated from muscle metabolism, typically filtered through the kidneys and released in urine, with increased levels in blood indicating impaired kidney function.

Laboratory tests used to evaluate how well the kidneys are working through examination of blood and urine.

A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.

A process of separating particulate matter from a fluid, such as air or a liquid, by passing the fluid carrier through a medium that will not pass the particulates. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

PUROMYCIN derivative that lacks the methoxyphenylalanyl group on the amine of the sugar ring. It is an antibiotic with antineoplastic properties and can cause nephrosis.

Pathological processes of the KIDNEY without inflammatory or neoplastic components. Nephrosis may be a primary disorder or secondary complication of other diseases. It is characterized by the NEPHROTIC SYNDROME indicating the presence of PROTEINURIA and HYPOALBUMINEMIA with accompanying EDEMA.

Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.

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.

The circulation of the BLOOD through the vessels of the KIDNEY.

An extracellular cystatin subtype that is abundantly expressed in bodily fluids. It may play a role in the inhibition of interstitial CYSTEINE PROTEASES.

A kidney disease with no or minimal histological glomerular changes on light microscopy and with no immune deposits. It is characterized by lipid accumulation in the epithelial cells of KIDNEY TUBULES and in the URINE. Patients usually show NEPHROTIC SYNDROME indicating the presence of PROTEINURIA with accompanying EDEMA.

Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.

Conditions in which the KIDNEYS perform below the normal level for more than three months. Chronic kidney insufficiency is classified by five stages according to the decline in GLOMERULAR FILTRATION RATE and the degree of kidney damage (as measured by the level of PROTEINURIA). The most severe form is the end-stage renal disease (CHRONIC KIDNEY FAILURE). (Kidney Foundation: Kidney Disease Outcome Quality Initiative, 2002)

A technetium imaging agent used in renal scintigraphy, computed tomography, lung ventilation imaging, gastrointestinal scintigraphy, and many other procedures which employ radionuclide imaging agents.

Water-soluble proteins found in egg whites, blood, lymph, and other tissues and fluids. They coagulate upon heating.

Specialized non-fenestrated tightly-joined ENDOTHELIAL CELLS with TIGHT JUNCTIONS that form a transport barrier for certain substances between the cerebral capillaries and the BRAIN tissue.

A contrast medium in diagnostic radiology with properties similar to those of diatrizoic acid. It is used primarily as its sodium and meglumine (IOTHALAMATE MEGLUMINE) salts.

A darkly stained mat-like EXTRACELLULAR MATRIX (ECM) that separates cell layers, such as EPITHELIUM from ENDOTHELIUM or a layer of CONNECTIVE TISSUE. The ECM layer that supports an overlying EPITHELIUM or ENDOTHELIUM is called basal lamina. Basement membrane (BM) can be formed by the fusion of either two adjacent basal laminae or a basal lamina with an adjacent reticular lamina of connective tissue. BM, composed mainly of TYPE IV COLLAGEN; glycoprotein LAMININ; and PROTEOGLYCAN, provides barriers as well as channels between interacting cell layers.

The property of blood capillary ENDOTHELIUM that allows for the selective exchange of substances between the blood and surrounding tissues and through membranous barriers such as the BLOOD-AIR BARRIER; BLOOD-AQUEOUS BARRIER; BLOOD-BRAIN BARRIER; BLOOD-NERVE BARRIER; BLOOD-RETINAL BARRIER; and BLOOD-TESTIS BARRIER. Small lipid-soluble molecules such as carbon dioxide and oxygen move freely by diffusion. Water and water-soluble molecules cannot pass through the endothelial walls and are dependent on microscopic pores. These pores show narrow areas (TIGHT JUNCTIONS) which may limit large molecule movement.

The minute vessels that connect the arterioles and venules.

The end-stage of CHRONIC RENAL INSUFFICIENCY. It is characterized by the severe irreversible kidney damage (as measured by the level of PROTEINURIA) and the reduction in GLOMERULAR FILTRATION RATE to less than 15 ml per min (Kidney Foundation: Kidney Disease Outcome Quality Initiative, 2002). These patients generally require HEMODIALYSIS or KIDNEY TRANSPLANTATION.