The UT-B urea transporter is the major urea transporter in red blood cells and kidney descending vasa recta. Humans and mice that lack UT-B have a mild urine-concentrating defect. Whether deletion of UT-B altered the expression of other transporter proteins involved in urinary concentration was tested. Fluorescence-based real-time reverse transcription-PCR and Northern blot analysis showed upre...

To determine if urea diffuses into reticulo-ruminal water (RRW) during urea dilution estimation of body composition, four 450-kg heifers were infused intravenously with a solution containing 65.05 g urea plus .95 g 15N-urea, after a 20-h removal of feed. Blood, urine and rumen fluid were collected before infusion and at various times for 120 min after infusion. Plasma 15N clearance was describe...

We studied the absorption, assimilation, translocation and distribution of nitrogen (N) from urea applied in autumn to leaves of 1-year-old potted Fuji/M26 apple (Malus domestica Borkh) trees. In early October, all leaves of each tree were painted with either 3% urea (enriched to 10 atom % with 15N) or water (control trees). Four trees were harvested before the treatment and N and amino acid co...

We probe the urea-denaturation mechanism using molecular dynamics simulations of an elementary "folding" event, namely, the formation of end-to-end contact in the linear hydrocarbon chain (HC) CH(3)(CH(2))(18)CH(3). Electrostatic effects are examined using a model HC in which one end of the chain is positively charged (+0.2e) and the other contains a negative charge (-0.2e). For these systems m...

We extended a region-based mathematical model of the renal medulla of the rat kidney, previously developed by us, to represent new anatomic findings on the vascular architecture in the rat inner medulla (IM). In the outer medulla (OM), tubules and vessels are organized around tightly packed vascular bundles; in the IM, the organization is centered around collecting duct clusters. In particular,...

Aceclofenac is a non-steroidal anti-inflammatory drug (NSAID) that exhibits analgesic, antipyretic and anti-inflammatory activities. It is practically insoluble in water. The effect of hydrotropes such as urea and sodium citrate and blends (urea + sodium citrate) on the solubility of aceclofenac was investigated. The enhancement in the solubility of aceclofenac was more than 5 and 25 folds in 3...

rh~~~~~, MARY &LEN. Renal response to solute loading in infant rats: relation to anatomical development. Am. J. Physiol. 2 19(4) : 10891097. 1970.--.Dehydrated infant rats, 10 and 20 days old, received acute urea and salt loads. Urea-loaded lo-day-old rats were unable to enhance urinary concentrating ability. In contrast, 20-day-old rats showed enhanced concentrating ability accompanied by a ri...

protein nutritional status of dairy cows. Milk urea nitrogen reflects the amount of urea found in milk and these values are closely correlated with the concentration of urea found in the blood. MUN values should not be used by themselves when evaluation a herd’s feeding program but can be used in conjunction with evaluating milk production records, feeding management practices, and dry matter, ...

1. To obtain information about the mechanism of the natriuresis induced by angiotensin, its effect on the distribution of electrolytes, urea and water in rabbit kidneys was examined. 2. In five control experiments, after infusion of normal saline at a low rate for several hours, the animals were killed and their kidneys removed and analysed for Nay K, C1, urea and water content at five levels f...