Endothelium plasma membrane

Another vasoactive substance produced by the endothelium is thromboxane A2 (TxA2). Normally, small amounts of TxA2 are released continuously however, increased synthesis appears to be associated with some cardiac diseases. Synthesized from arachidonic acid, a plasma membrane phospholipid, TxA2 is a potent vasoconstrictor. Furthermore, this substance stimulates platelet aggregation, suggesting that it plays a role in thrombotic events such as myocardial infarction (heart attack). Nonsteroidal anti-inflammatory drugs such as aspirin and ibuprofen block formation of TxA2 and reduce formation of blood clots. 

Figure 11.1 Ultrastructure of the human lung alveolar barrier. The tissue specimen is obtained via lung resection surgery. (A) Section through a septal wall of an alveolus. The wall is lined by a thin cellular layer formed by alveolar epithelial type I cells (ATI). Connective tissues (ct) separate ATI cells from the capillary endothelium (en) within which an erythrocyte (er) and granulocyte (gc) can be seen. The minimal distance between the alveolar airspace (ai) and erythrocyte is about 800-900 nm. The endothelial nucleus is denoted as n. (B) Details of the lung alveolar epithelial and endothelial barriers. Numerous caveolae (arrows) are seen in the apical and basal plasma membranes of an ATI cell as well as endothelial cell (en) membranes. Caveolae may partake transport of some solutes (e.g., albumin). (C) ATII cells (ATII) are often localised in the comers of alveoli where septal walls branch off. (D) ATII cells are characterised by numerous multilamellar bodies (mlb) which contain components of surfactant. A mitochondrion is denoted as mi.

Baxter IR, Young JC, Armstrong G, Foster N, Bogenschutz N, Cordova T, Peer WA, Hazen SP, Murphy AS, Harper JF. 2005. A plasma membrane H + -ATPase is required for the formation of proanthocyanidins in the seed coat endothelium of... 

Figure 46-1 Volume and distribution of total body water. Note that the intracellular and ECF compartments (ICF and ECF, respectively) are separated by cellular plasma membranes, and within the ECF, interstitial and intravascular fluids are separated by the capillary endothelium.The volumes indicated represent water and not total volume.

The diffusing capacity of the lung for carbon monoxide (CO) is a measure of the ability of the alveolar capillary membrane to transfer or conduct gases from the alveoli to the blood. This transport process is entirely a passive one brought about by diffusion. As described previously in Section 2.2, the barriers for diffusion consist of surfactant, alveolar epithelium, interstitital fluid, capillary endothelium, plasma, and the red blood cell membrane. 

The iron-cataiyzed generation of hydroxyl radicals accounts for much of the cytotoxicity of the element. The resultant lipid peroxidation causes damage to the plasma membrane and to intracellular membranes of the mitochondria and lysosomes (Hershko and Weatherall 1988). Free radicals have been implicated in iron-induced injury to many tissues, including lung (Adamson et al. 1993), kidney (Alfrey et al. 1989), endothelium (Brieland et al. 1992), and heart (Hershko et al. 1987 Link et al. 1993 Scott et al. 1985). Iron-catalyzed lipid peroxidation in cell culture systems and its sup-... 

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