Increase In Urea Content Research Articles

Blood urea content changes in man under hypokinesia.

It has been demonstrated that hypokinesia (diminished muscular activity) leads to an increase in blood urea content in man. Against this background the objective of this investigation was to determine blood urea content under hypokinesia (HK) on 17 physically healthy men aged 19-23 yr. They were divided into three groups: the 1st group (5 men) was examined under HK, the 2nd group (4 men) was studied during the background period (BGP) as well as in the readaptation period (RTP), and the 3rd group (8 men) was placed under ordinary conditions and served as control. For the simulation of the hypokinetic effect the men were kept under a rigorous bed rest regime for 16 days. Blood urea, blood creatinine, urine urea, and urine creatinine were measured. The results were processed statistically. The most pronounced increased urea content was observed in the men with an initial low concentration (3.3-4.2 mmole/liter). Variations in the urea concentration were analogous and manifested a reduction during the initial days and an elevation thereafter. Creatinine excretion and clearance were reduced uniformly and significantly during the initial 10 days of HK. It was concluded that diminished muscular activity induced an increase in urea content and a decrease in creatinine clearance in man.

Cell volume regulation in juveniles of xenopus laevis in hypertonic urea solution

Abstract o 1. Juvenile Xenopus laevis can be easily adapted to 300 mOsm urea in the external medium, which makes it possible to study cell volume regulatory mechanisms induced by a penetrating external substance (high osmolality and low tonicity). 2. Water loss was caused during the first days of adaptation. 3. Despite urea entrance, urea was not equally distributed, the internal concentration reached only about 1/3 of the external. 4. Increase of plasma osmolality above external level was observed due to an increase of Na + , Cl − and urea concentration. 5. Decrease of Na content and increase of urea content of the cell resulted together with a decrease of intracellular space. 6. Intracellular volume reduction was not regulated during the experimental period which clearly distinguishes this type of adaptation from adaptation to NaCl or impermeable mannitol.

Urea content and urea production via the ornithine-urea cycle pathway during the ontogenic development of two teleost fishes

1. 1. In the oviparous S. gairdnerii and in the ovoviviparous P. reticulata. the urea level is decreasing at the end of the embryonic development toward the low values found in adult fishes. 2. 2. In P. reticulata, the urea content increases sharply at the end of vitellogenesis and remains high in early embryos. 3. 3. These modifications in urea level can be related, at least partly, to the possibilities of urea formation through the urea cycle pathway. 4. 4. The differences in urea formation capabilities of the two species can be best explained when considering differences in the NH 2-group metabolism related to reproduction characteristics. 5. 5. Application of hyperosmotic media leads to an increase in urea content and formation during the embryonic development of both species.

Changes in composition of harvested mushrooms ( Agaricus bisporus)

Post-harvest changes in the biochemical composition of the mushroom were studied. Non-structural polysaccharide was found at levels greater than 10% dry wt in the fresh mushroom. After 4 days storage, the level had decreased to below 5% dry weight. The polysaccharide appeared to contain only glucose residues joined by α-1,4 and α-1,6 linkages. The chitin content of cell walls increased by ca 50% during 4 days storage, while cell wall glucan decreased. There was a large increase in urea content.