In the terminal part of the kidney collecting duct, rapid urea reabsorption is essential to maintaining medullary hypertonicity, allowing maximal urinary concentration to occur. This process is mediated by facilitated urea transporters on both apical and basolateral membranes. Our previous studies have identified three rat urea transporters involved in the urinary concentrating mechanism, UT1, ...

Urea is a protein unfolding agent that can accumulate to locally high concentrations in tissues of many organisms. We used Drosophila melanogaster to test the hypothesis that urea loading would promote formation of isoaspartate (beta-carboxyl-linked aspartate), a common form of protein damage that occurs most readily in unstructured polypeptides and flexible regions of folded proteins. Ten popu...

Abstract This study sought to compare the efficiency of different nitrogen (N) fertilizer forms applied perennial ryegrass swards that were rotationally grazed by dairy cows or sheep under Irish conditions for two three years. A 3 × 2 factorial random complete block design plot arrangement was used calcium ammonium nitrate (CAN), urea and + N-(n-butyl) thiophosphoric triamide (urea NBPT) at 150...

The electrical activity of the caecum was recorded during periods of two months in 5 ewes receiving different diets. For a similar amount of dry matter ingested, the frequency of caecal contractions was diminished on concentrates with urea versus hay ad libitum but not on concentrates without urea. The frequency also decreased when the level of food intake on hay diet or on concentrates without...

This study extends permeability (P) data on chloride, urea and water in red blood cells (RBC), and concludes that the urea transporter (UT-B) does not transport water. P of chick, duck, Amphiuma means, dog and human RBC to (36)Cl(-), (14)C-urea and (3)H2O was determined under self-exchange conditions. At 25°C and pH 7.2-7.5, PCl is 0.94 × 10(-4)-2.15 × 10(-4) cm s(-1) for all RBC species at [Cl...

experiments were carried out in a commercial orchard during 1994, 1995 and 1996 to determine the influence of chemical thinning on characterisics of fruit and alternate bearing of native olive (olea europea l) cvs. dezfoul and fishomi at early fruitlet stage. in 1994, branch sprays of naphthalene acetic acid (100, 150 and 200 mg/l), naphthalene acetamide (200 and 300 mg/l) and urea (0.6 and 1.2...

Case report A 47-year-old woman was admitted to the Royal Sussex County Hospital on 11 June 1968 in renal failure due to chronic pyelonephritis. Investigations. Hb 52%4, WBC 7200/m3, blood urea 346 mg/100 ml, creatinine clearance 4-2 ml/min, serum sodium 140 mEq/l, calcium 8-0 mg/100 ml, phosphate 12-2 mg/100 ml, alkaline phosphatase 16-0 KA Units; urinary sodium 26 mEq/l, potassium 22-3 mEq/l,...

Chaffed wheat straw was treated with a seven per cent solution of urea and sealed for three weeks before feeding to sheep. Mature wethers received either this urea-treated straw or straw that had received an equivalent amount of urea mixed in with it at feeding. Both straws were fed either with or without lupins at 200 g/hd/d for seven weeks. DM intake was increased both by the urea treatment a...

In normal rats, vasopressin and hyperosmolality enhance urea permeability (P(urea)) in the terminal, but not in the initial inner medullary collecting duct (IMCD), a process thought to occur through the UT-A1 urea transporter. In the terminal IMCD, UT-A1 is detected as 97- and 117-kDa glycoproteins. However, in the initial IMCD, only the 97-kDa form is detected. During streptozotocin-induced di...