Body fluids distribution

Osmotic pressure plays a major role In the maintenance of this dynamic equilibrium within an individual. The factors responsible for compartmentallzation of body fluids appear to be largely osmotic and related to electrol5de concentration. This is further modified by the selective nature of the biomembranes. The body fluids distribute themselves across membrane structures in such a way as to equalize osmotic pressure. This state is one of osmotic equilibrium. 

After inorganic mercuric salts are absorbed and dissociated into the body fluids and in the blood, they are distributed between the plasma and erythrocytes. Aryl mercuric compounds and alkoxy mercuric compounds are decomposed to mercuric ions, which behave similarly. 

It is important to appreciate that the magnitude of the absorbed dose, the relative amounts of bio transformation product, and the distribution and elimination of metaboUtes and parent compound seen with a single exposure, may be modified by repeated exposures. For example, repeated exposure may enhance mechanisms responsible for biotransformation of the absorbed material, and thus modify the relative proportions of the metaboUtes and parent molecule, and thus the retention pattern of these materials. Clearly, this could influence the likelihood for target organ toxicity. Additionally, and particularly when there is a slow excretion rate, repeated exposures may increase the possibiUty for progressive loading of tissues and body fluids, and hence the potential for cumulative toxicity. 

Pharmacokinetic studies are designed to measure quantitatively the rate of uptake and metaboHsm of a material and determine the absorbed dose to determine the distribution of absorbed material and its metaboHtes among body fluids and tissues, and their rate of accumulation and efflux from the tissues and body fluids to determine the routes and relative rates of excretion of test material and metaboHtes and to determine the potential for binding to macromolecular and ceUular stmctures. 

It is generally assumed that ingested tritiated water is rapidly absorbed and uniformly distributed in the body fluids, with the result that the entire... 

ChEs present several amphiphilic and soluble homo-and hetero-oligomeric molecular forms in tissues and body fluids, with different tissue distributions (Fig. 1). 

FIGURE 10-2. Distribution of body fluids showing the extracellular fluid volume, intracellular body fluid volume, and total body fluids in a 70 kg adult. Extracellular volume (ECV) comprises 14 liters of total body fluid (42 liters). Plasma volume makes up approximately 3 liters of the 14 liters of ECV. Intracellular volume accounts for the remaining 28 liters of total body fluids with roughly 2 liters being located within the red blood cells. Blood volume (approximately 5 liters) is also depicted and is made up of primarily red blood cells and plasma. (Reprinted from Guyton AC, Hall JE. Textbook of Medical Physiology. 8th ed. Philadelphia Saunders, 1991 275, with permission.)... 

Because disturbances in fluid balance are routinely encountered in clinical medicine, it is essential to have a thorough understanding of body fluid compartments and the therapeutic use of fluids. Similarly, disturbances in serum sodium, potassium, calcium, phosphorus, and magnesium are ubiquitous and must be mastered by all clinicians. Dysregulation of fluid and/or electrolyte status has serious implications regarding the concepts of drug absorption, volumes of distribution, and toxicity. Similarly, many medications can disrupt fluid and/or electrolyte balance as an unintended consequence. 

Probably the most accessible techniques employed for Li+ analyses are AAS and FES [26]. Although both of these methods are destructive to the sample and are subject to significant interference effects, the methods have been developed and used successfully for many years. Li+ levels in solution, in body fluids, and in solubilized tissues have been determined, making a significant contribution to the understanding of Li+ distribution in the body, and of the membrane transport of Li+ in various systems. 

A hypothetical volume of body fluid into which the chemical distributes, ft is not a real volume, but is a proportionality constant relating the amount of chemical in the body to the measured concentration in blood or plasma. 

Distribution of in Selected Tissues and Body Fluids of Male Rats 24 and 48 Hours After... 

TABLE 2-4. Distribution of C in Selected Tissues and Body Fluids of Male Rats 24 and 48 Hours After a Single Oral Dose of 15 mg/kg [U- " C]-1,2-Dibromoethane ... 

Distribution relates to the reversible transfer of a substance between various parts of the organism, i.e., body fluids or tissues. 

Plasma protein binding of meropenem is approximately 2%. The volume of meropenem distribution is 15.7 to 26.68 L. Meropenem penetrates well into most body fluids and tissues, including cerebrospinal fluid, achieving concentrations... 

Sparfloxacin - Sparfloxacin is well absorbed following oral administration. Steady-state concentration was achieved on the first day by giving a loading dose that was double the daily dose. Oral absorption of sparfloxacin is unaffected by administration with milk or food, including high-fat meals. Sparfloxacin distributed well into the body. It penetrates well into body fluids and tissues. Sparfloxacin is metabolized by the liver. It is excreted in the feces (50%) and urine (50%). 

Distribution - INH readily diffuses into all body fluids (including cerebrospinal, pleural, and ascitic), tissues, organs, and excreta (saliva, sputum, feces). It also passes through the placental barrier and into breast milk in concentrations comparable to those in plasma. 

Absorption/Disthbution - When given orally, cycloserine is rapidly absorbed, reaching peak plasma concentrations in 4 to 8 hours. It is widely distributed throughout body fluids and tissues cerebrospinal fluid levels are similar to plasma. 

Distribution - Tinidazole is distributed into virtually all tissues and body fluids and crosses the blood-brain barrier. The apparent volume of distribution is approximately 50 L. Plasma protein binding of tinidazole is 12%. Tinidazole crosses the placental barrier and is secreted in breast milk. 

Higher concentration of drugs that distribute in body fluids increased distribution and often prolonged elimination half-life of fat-soluble drugs... 

They are well absorbed after oral administration with a bioavailability of 70-80%. They have a rather low protein binding, 20 0%, and are widely distributed in tissues, body fluids and bone. They are eliminated mainly by glomerular filtration and tubular secretion with a half-life of 3-7 hours. Up to 40% of the dose is metabolized by the liver. 

Unlike the genome the proteome is not a static but a dynamic and constantly changing entity that is cell- and tissue-specific and dependent on the environment. Because of the dynamic nature of protein expression and fimction, these properties need to be determined quantitatively in a time-dependent manner. Proteomics, the study of the proteome, involves the analysis of the complete pattern of the expressed proteins and their post-translational modifications in a cell, tissue, or body fluid. An integrated view of any living system hence requires an analysis that takes into account the spatial as well as temporal distribution of all the proteins in a cell or tissue. The analytical effort that is necessary to deliver such an integrated view is by several orders of magnitude more complicated than that of the recently finished human genome (Lander ef al. 2001 Venter et al. 2001). 

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