Tissue distribution, macromolecular

Creek, M.R. et al., Tissue distribution and macromolecular binding of extremely low doses of [14C]-benzene in B6C3F mice, Carcinogenesis, 18(12), 2421, 1997. 

Sosnowski, S., Wozniak, P. Lewandowska-Szumiel, M. (2006). Polyester scaffolds with bimodal pwre size distribution for tissue engineering. Macromolecular Bioscience 6(6) 425-434. 

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. 

The biodistribution of CN to various systemic tissues will determine the relative proportions of CN present at detoxification and target tissue or cellular sites. For example, inhaled or percutaneously absorbed CN enters the systemic circulation and only a small proportion of the absorbed dose will be available for first-pass detoxification, particularly in the liver. In contrast, a high proportion of a p.o. dose will pass through the liver and be available for first-pass detoxification. However, hepatic detoxification processes may be complex, since it has been demonstrated that dietary variations that cause alterations in hepatic sulfurtransferase activity do not correlate with CN toxicity (Rutkowski et ah, 1985), and extensive chemical or surgical injury to the liver does not increase the susceptibility of the mouse to CN toxicity (Rutkowski et ah, 1986). The influence of route on toxicity is probably due to the relative effects of plasma transulfuration, sequestration by erythrocytes, intracellular macromolecular binding, and the differential distribution to all tissues with a detoxification capacity. 

Hemicelluloses occur in structural variations differing in side-chain types, distribution, localization, and/or types and distribution of glycoside linkages in the macromolecular backbone. Polysaccharides might be differentiated from various points of view, such as function in plant tissues [reserve, supporting], primary structure, occurrence in plant tissues, etc. [15]. 

In conclusion, the macromolecular properties of polymers and their interactions with cell surfaces result in a specific pharmacokinetic behaviour of polymers. The routes of parenteral administration are far from being equivalent, e.g. the intraperi-toneal application often used cannot substitute the intravenous administration. Molecular parameters of the polymer circulating in the coitral compartment are changed in time not necessarily by a direct biological modification of the polymer but as a consequence of a selective processing of different fractions. The intracellular accumulation in secondary lysosomes is the only proven mode of persistence of a soluble polymer in tissues. Variations in the chemical structure of the polymer may result in a different pattern of polymer distribution in the body as a consequence of a different rate of cellular accumulation. 

---