Urea transporter (UT) proteins, including isoforms of UT-A in kidney tubule epithelia and UT-B in vasa recta endothelia and erythrocytes, play an important role in the urine concentration mechanism by mediated an intra renal urea recycling, suggesting that functional inhibition of these proteins could have therapeutic use as a novel class of diuretic. Recently several classes of UT inhibitors h...

Marine elasmobranch fishes maintain high urea concentrations and therefore must minimize urea loss to the environment in order to reduce the energetic costs of urea production. Previous studies have identified a facilitated urea transporter in the kidney of the dogfish. We examined mechanisms of urea transport in the kidney of the little skate Raja erinacea using an isolated brush-border membra...

Urea synthesized commercially and formed naturally as a by-product of cellular metabolism is an important source of nitrogen (N) for primary producers in aquatic ecosystems. Although urea is usually present at ambient concentrations below 1 μM-N, it can contribute 50% or more of the total N used by planktonic communities. Urea may be produced intracellularly via purine catabolism and/or the ure...

Urea, in concentrations unique to the renal medulla, increases transcription and protein expression of several immediate-early genes (IEGs) including the zinc finger-containing transcription factor, Egr-1. In the present study, the proximal 1.2 kb of the murine Egr-1 5' -flanking sequence conferred urea-responsiveness to a heterologous luciferase reporter gene when transiently transfected into ...

Epithelial cells derived from the mammalian kidney medulla are responsive to urea at the levels of signal transduction and gene regulation. Hybridization of RNA harvested from control- and urea-treated murine inner medullary collecting duct (mIMCD3) cells with a cDNA expression array encoding stress-responsive genes suggested that heme oxygenase (HO)-1 mRNA was upregulated by urea. RNase protec...

Rhodosporidium toruloides and Tetradesmus obliquus pure mixed cultures were grown on primary brewery wastewater (PBWW), with without supplementation of sugarcane molasses (SCM) urea. R. developed in was not able to grow PBWW, or supplementation, but grew the microalga T. all media. In contrast, develop. Higher biomass productivity (149.3 mg L−1 h−1) obtained for culture using PBWW supplemented ...

this experiment was conducted to improve the nutritive value of barley stubble for two consecutive years. after harvesting crop, at first year, a completely randomized design, with a 3 × 3 factorial experiment was conducted in which 27 plots were divided into nine treatments. the treatments including zero, 2.5 and five percent urea each with zero, three and six percent molasses were mixed with ...

In osmoregulating teleost fish, urea is a minor nitrogen excretory product, whereas in osmoconforming marine elasmobranchs it serves as the major tissue organic solute and is retained at relatively high concentrations ( approximately 400 mmol/l). We tested the hypothesis that urea transport across liver mitochondria is carrier mediated in both teleost and elasmobranch fishes. Intact liver mitoc...