Tissue transport

FIGURE 5.13 Two basic types of biological transport are (a) transport within or between different cells or tissues and (b) transport into or out of cells. Proteins function in both of these phenomena. For example, the protein hemoglobin transports oxygen from the lungs to actively respiring tissues. Transport proteins of the other type are localized in cellular membranes, where they function in the uptake of specific nutrients, such as glucose (shown here) and amino acids, or the export of metabolites and waste products. 

Organ/tissue transport and/or perfusion fluid with antimicrobial or other drug agent, that is, preservation solutions. 

In vitro methods Flux across excised human or animal tissue Transport through epithelial cell monolayers... 

The coefficient of hydraulic permeability (Lp) of ozone-treated bean leaf tissue tends to decrease when measured by water loss or uptake (Fig. 6). Here, ozone-treated tissue was equilibrated with 0.2 M mannitol (approximately isotonic) immediately after exposure. The tissue was then either allowed to take up tritiated water or, after a period of tritiated water uptake, allowed to lose tritiated water into a mannitol solution. In both the influx and efflux experiments, ozone-treated tissue transported tritiated water at a lower rate than control tissue. 

Because plasma protein and tissue binding influences the amount of drug in each body compartment, the volume of distribution of a drug may be dose dependent (nonhnear). A limited number of binding sites may result in capacity-limited binding in plasma or tissues. Transport from the blood may also be capacity limited. Examples of dose-dependent volume changes show that the volume of distribution of recombinant human tumor necrosis factor (TNF) alpha decreases sharply with a fourfold increase in dose and that the volume of distribution of recombinant human DNase,... 

Mutagen in tissues transport diffusion Tissue dose mM mMh... 

Serum albumin circulates in the blood stream transporting essential nutrients such as fatty acids to peripheral tissue. Transported molecules, called ligands, often have a special affinity for selected binding sites on proteins and nucleic acids. In this experiment, the dynamics of ligand-protein interactions will be explored with the binding of the dye phenol red to bovine serum albumin. The technique of gel filtration will be used to separate the dye-protein complex. Data will be analyzed in order to construct binding curves. 

R.D. Fross, P.C. Wamke and D.R. Groothuis, Blood flow and blood-to-tissue transport in 9L gliosarcomas the role of the brain tumor model in drug delivery research, J. Neuro-Oncol. 11 (1991) 185-197. 

A steady-state diffuse reflectance spectroscopy instrument typically includes a broadband fight source, intermediate optics, spatially separated delivery-collection optical fiber probes,77 and a CCD-based grating spectrometer. Frequency-based approaches have also been pursued.78 Correlations between the glucose concentration and the tissue transport scattering coefficient have been observed.77,78... 

Fresh tissue transport from remote areas is more difficult and involves phytosanitary, export, and import permits (see above). We have had no problem in carrying fresh tissue on wet ice in Styrofoam containers as airline hold or canyon baggage from Central and South America, Asia,... 

Lithium occurs naturally as a mixture of the two stable isotopes Li (7%) and Li (93%). Until recently these have not been readily distinguished. We have developed a technique for the identification and estimation of the two stable isotopes using AAS techniques and have applied this to a pharmacokinetic study in humans (70). In a parallel study, Thellier, using neutron activation to measure Li in biological samples, has shown that lithium accumulates in the less well-myelinated areas of the central nervous system. The technique was extended to study the tissue transport of the two stable isotopes of lithium (71). 

The functions and fate of i.-ascorbic acid in humans and other primates are reviewed in this chapter. Topics included are use of subhuman primates for research in nutrition evolution and subsequent loss of ascorbic acid biosynthesis absorption, tissue transport, and distribution of ascorbic acid and catabolism, functions, and requirements of ascorbic acid. In retrospect, the insight provided by this chapter suggests new work areas of emphasis for developing better understanding of the vitamins role in human health. 

The compartments and barriers to methylmercury transport in the tissue compartments and placenta are shown in Figure 2-6. The cell membrane is assumed to be the barrier for methylmercury transport for all tissues except the brain and placenta. The barrier to methylmercury transport to the brain is the endothelial cell wall of the cerebral vascular system (the blood-brain barrier). The placenta is modeled as four compartments, with separate transfer constants for placental barrier and placental tissue transport. There is a tissue compartment for both the maternal and fetal sides of the placenta. 

GLUTS (small intestine) Small intestine, kidney, skeletal muscle, brain, and adipose tissue Transports fructose (not glucose)... 

Serine and Threonine Can Be Directly I laminated Peripheral Tissues Transport Nitrogen to the Liver... 

CFTR Exocrine tissue Transports Cl ions Cystic fibrosis... 

Transcellular Process by which matter passes through the cell membranes to reach the other side of a tissue. Transport electron carriers Group of carriers that catalyze electron flow across a membrane. 

Warnke PC, Blasberg RG, Groothuis DR. The effect of hyperosmotic blood-brain barrier disruption on blood-to-tissue transport in ENU-induced gliomas. Ann Neurol 1987 22 300-305. 

Quantitative and qualitative analysis of plasma and serum proteins forms an essential part of the clinical diagnosis of an increasing number of diseases. Electrophoretic separation of these proteins is an integral part of such analyses. Because of its role in tissue-to-tissue transport, changes in plasma protein composition may reflect metabofic disorders in all parts of the body. 

Burkhart, S. S. and Athanasiou, K. A. (July-August 2003). The twist-lock concept of tissue transport and future fixation without knots. Arthroscopy The Journal of Arthroscopic and Related Surgery, 19 (6), 613-625. 

The search for the site(s) of auxin transport has followed three main lines (1) transport experiments using tissues of differing anatomical-histological characteristics (2) macro- and microautoradiographic studies of tissue transporting auxin and (3) analyses of membrane fractions with specific binding properties. 

Differences in the structure of cell walls of various plants and their parts are related to the differentiation of the primary cells, cellulose crystalinity and the type and amount of non-cellulose polysaccharides. Deposition of additional layers of cellulose (in the form of clearly oriented parallel microfibrils), deposition of noncellulose polysaccharides and lignification of the polysaccharide network, which is due to polymerisation of phenolic compounds, results in the formation of thick secondary cell walls, which have various special functions. For example, they ensure the rigidity of tissues, transport of water and have protective and other functions. 

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