The access of drugs to variofis sites of action in the body is impeded by a succession of membranes. Likewise, the removal of a drug or foreign substance from the body is similarly dependent on the ability of the substance under consideration to permeate biological barriers. A con-committant problem generally arises concerning the overall time course of drug action: that of drug storage through binding or similar processes. Schanker (196h) however, has stated that "Although the mechanisms of localization and those of membrane transfer are in many respects different problems, there are some instances in which they are inseparable parts of the same problem." Examples include phenomena whereby the binding of a substance to the cell membrane is required for transport (Rosenberg and Wilbrandt, 1955; Peters; 1960; Lacko and Burger, 1961; Schwartz and Matsui, 1967; Stein, 1967).
From a functional standpoint, body membranes may be classified in three major categories (Schanker, 1962b); membranes several cell layers thick such as skin, those one cell layer thick such as the brush border epithelium of the intestine, and membranes less than one cell in thickness such as the cell membrane itself or the membranes of organelles (e.g. mitochondria). Thus, except for the barriers associated with subcellular structures, the cell membrane 6 (or plasma membrane as it is often called) may be considered the fundamental unit of body membranes in general.
| Identifer | oai:union.ndltd.org:vcu.edu/oai:scholarscompass.vcu.edu:etd-6028 |
| Date | 01 January 1972 |
| Creators | Putney, James W., Jr. |
| Publisher | VCU Scholars Compass |
| Source Sets | Virginia Commonwealth University |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Theses and Dissertations |
| Rights | © The Author |
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