Track topics on Twitter Track topics that are important to you
In the late 1980s, urea permeability measurements produced values that could not be explained by paracellular transport or lipid phase diffusion. The existence of urea transport proteins were thus proposed and less than a decade later, the first urea transporter was cloned. The family of urea transporters has two major subgroups, designated SLC14A1 (or UT-B) and Slc14A2 (or UT-A). UT-B and UT-A gene products are glycoproteins located in various extra-renal tissues however, a majority of the resulting isoforms are found in the kidney. The UT-B (Slc14A1) urea transporter was originally isolated from erythrocytes and two isoforms have been reported. In kidney, UT-B is located primarily in the descending vasa recta. The UT-A (Slc14A2) urea transporter yields six distinct isoforms, of which three are found chiefly in the kidney medulla. UT-A1 and UT-A3 are found in the inner medullary collecting duct (IMCD), while UT-A2 is located in the thin descending limb. These transporters are crucial to the kidney's ability to concentrate urine. The regulation of urea transporter activity in the IMCD involves acute modification through phosphorylation and subsequent movement to the plasma membrane. UT-A1 and UT-A3 accumulate in the plasma membrane in response to stimulation by vasopressin or hypertonicity. Long-term regulation of the urea transporters in the IMCD involves altering protein abundance in response to changes in hydration status, low protein diets, or adrenal steroids. Urea transporters have been studied using animal models of disease including diabetes mellitus, lithium intoxication, hypertension, and nephrotoxic drug responses. Exciting new genetically engineered mouse models are being developed to study these transporters.
Renal Division, Department of Medicine, and Department of Physiology, Emory University School of Medicine, Atlanta, GA, 30322, USA.
This article was published in the following journal.
Name: Pflugers Archiv : European journal of physiology
Urea transporters are membrane proteins that selectively allow urea molecules to pass through. It is not clear how these transporters allow rapid conduction of urea, a polar molecule, in spite of the ...
Urea is transported by urea transporter proteins in kidney, erythrocytes, and other tissues. Mice in which different urea transporters have been knocked out have urine-concentrating defects, which has...
The Xpert(®) MTB/RIF assay is widely used for Mycobacterium tuberculosis detection. However, specimen transport remains a challenge. PrimeStore Molecular Transport Medium(®) (PS-MTM) inactivates spe...
Data on quantitative metabolic liver functions in the life-threatening disease alcoholic hepatitis are scarce. Urea synthesis is an essential metabolic liver function that plays a key regulatory role ...
Mercury exists in the environment in various forms, all of which pose a risk to human health. Despite guidelines regulating the industrial release of mercury into the environment, humans continue to b...
In this short-term study a method for the evaluation of the metabolic competency of the urea cycle in vivo will be assessed. In order to monitor the efficacy of new treatment options for p...
RATIONALE: The urea cycle is the process in which nitrogen is removed from the blood and converted into urea, a waste product found in urine . Urea cycle disorders are inherited disorders ...
The purpose of this study is to investigate if wearing of compression stockings influences the skin moisture. Conservative stockings are compared with urea containing compression stockings...
The purpose of this study is to determine if acetohydroxamic acid (AHA) can prevent hydrolysis of urea by inhibiting the bacterial urease of gut flora of both healthy control adults as wel...
Biobank is a program which collects biological samples, health information and imaging data from consented patients and stored them at the core facility. These information would be used to...
The process of moving proteins from one cellular compartment (including extracellular) to another by various sorting and transport mechanisms such as gated transport, protein translocation, and vesicular transport.
A class of drugs producing both physiological and psychological effects through a variety of mechanisms. They can be divided into "specific" agents, e.g., affecting an identifiable molecular mechanism unique to target cells bearing receptors for that agent, and "nonspecific" agents, those producing effects on different target cells and acting by diverse molecular mechanisms. Those with nonspecific mechanisms are generally further classed according to whether they produce behavioral depression or stimulation. Those with specific mechanisms are classed by locus of action or specific therapeutic use. (From Gilman AG, et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th ed, p252)
The process of moving specific RNA molecules from one cellular compartment or region to another by various sorting and transport mechanisms.
Gated transport mechanisms by which proteins or RNA are moved across the NUCLEAR MEMBRANE.
The urea concentration of the blood stated in terms of nitrogen content. Serum (plasma) urea nitrogen is approximately 12% higher than blood urea nitrogen concentration because of the greater protein content of red blood cells. Increases in blood or serum urea nitrogen are referred to as azotemia and may have prerenal, renal, or postrenal causes. (From Saunders Dictionary & Encyclopedia of Laboratory Medicine and Technology, 1984)
Within medicine, nutrition (the study of food and the effect of its components on the body) has many different roles. Appropriate nutrition can help prevent certain diseases, or treat others. In critically ill patients, artificial feeding by tubes need t...
Bioinformatics is the application of computer software and hardware to the management of biological data to create useful information. Computers are used to gather, store, analyze and integrate biological and genetic information which can then be applied...
Chronic kidney disease (CKD), also known as chronic renal disease, is a progressive loss in renal function over a period of months or years. The symptoms of worsening kidney function are non-specific, and might include feeling generally unwell and experi...