Water intracellular

Hydroxyurea is a ribonucleotide reductase inhibitor that prevents DNA synthesis and traditionally has been used in chemotherapy regimens. Studies in the 1990s also found that hydroxyurea increases HbF levels as well as increasing the number of HbF-containing reticulocytes and intracellular HbF. Other beneficial effects of hydroxyurea include antioxidant properties, reduction of neutrophils and monocytes, increased intracellular water content leading to increased red cell deformability, decreased red cell adhesion to endothelium, and increased levels of nitric oxide, which is a regulator involved in physiologic disturbances.22... 

Mainly the water resonance can often be used as an indicator for inflammations or tumours, because effective relaxation times tend to be prolonged in tissue with increasing interstitial or intracellular water content. As reported in Section 3.2, lipids (mainly consisting of triglycerides) reveal more stable relaxation characteristics in all tissues and no significant alterations have been reported so far. 

Taurine is a sulphur amino acid, which is not present in protein (see text). For the calculation from the amount in fresh (wet) tissue, e.g. pmol/g fresh tissue, it is assumed that the intracellular water makes up 40% of the weight. 

The volume ratio interstitial intracellular water varies with age and body weight On a percentage basis, interstitial fluid volume is large in premature or normal neonates (up to 50% of body water), and smaller in the obese and the aged. 

Potma, E. O., de Boeij, W. R, and Wiersma, D. A. 2001. Eemtosecond dynamics of intracellular water probed with nonlinear optical Kerr effect microspectroscopy. Biophys. J. 80 3019-24. 

The body is composed of about 70% water by weight. The fluid portion of the blood (plasma) accounts for 6 liters or about 4% of that total. Intracellular water constitutes about 41 % while interstitial (between cells) fluid is 13%. The rest is extracellular. Therefore solubility in water will be an important factor in drug distribution. Fat depots within adipose and other fatty tissues are also important in that they can sequester lipophilic molecules and release them very slowly back into the general blood circulation. This is the case with tetrahydrocannabinol (THC), the psychoactive component of marijuana. It shows two periods of presence in the blood the first immediately after consumption and the second a more lingering presence for up to 27 days after use. 

The total water in the body of an animal can be conveniently divided into three compartments the plasma water, the interstitial water, and the intracellular water. The way a foreign compound distributes into these compartments will profoundly affect the plasma concentration. If a compound is only distributed in the plasma water (which is 3 L in man), the plasma concentration will obviously be much higher than if it is distributed in all extracellular water ( 14 L) or the total body water 40 L). This may be quantified as a parameter known as the volume of distribution (VD), which can be calculated as follows ... 

Furosemide rarely causes the syndrome of inappropriate antidiuretic hormone secretion (SIADH) (although it has been found useful in treating some patients with SIADH who cannot tolerate water restriction (428)). In furosemide-induced cases (SEDA-7, 246), serum ADH concentrations were raised, total body sodium was normal, total body potassium greatly reduced, and intracellular water raised at the expense of extracellular fluid volume. However, such cases are rare, and no new cases have been published since this complication was reported in SEDA-7. 

For example, Swift and Barr established the proton NMR data with 170 relaxation studies on frog skeletal muscles272. They also found that the water relaxation is enhanced in muscles in comparison with pure water272. Cooke and Wien273 observed on partially dried rabbit psoas fibers two phases of muscle water a small phase, less than 4—5% of the total water, which interacts strongly with the proteins and has short relaxation times and a major phase. .. with longer relaxation times a major fraction of the intracellular water exists in a less mobile form than water in a salt solution 273. ... 

Yamada T. 2001. TH-NMR studies of the intracellular water of skeletal muscle fibres under various... 

Some relevant volumes of body compartments are (in liters) plasma water (3), erythrocyte water (3), extracellular water excluding blood (11), and intracellular water (24). The total body water is approximately 41 L. A comparison of selected drugs with apparent volumes of distribution (in liters) approximating various body compartments is shown in Table 2.6. 

Kreuzer-Martin, H.W., Ehleringer, J.R., and Hegg, E.L. 2005. Oxygen isotopes indicate most intracellular water in log-phase Escherichia coli is derived from metabolism. Proc. Natl. Acad. Sci. U.S.A. 102 17337-17341. 

Explain how fat depots in mammalian adipose tissues are sources of intracellular water. 

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